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1. Bridging Legends and Science: Field Evidence of a Large Tsunami that Affected the Kingdom of Tonga in the 15th Century

Author

Franck Lavigne, Julie Morin, Patrick Wassmer, Olivier Weller, Taaniela Kula, Ana V. Maea, Karim Kelfoun, Fatima Mokadem, Raphael Paris, Mukhamad Ngainul Malawani, Audrey Faral, Mhammed Benbakkar, Ségolène Saulnier-Copard, Céline M. Vidal, Tu’I’ahai Tu’I’afitu, Fuka Kitekei’aho, Martine Trautmann, and Christopher Gomez

Subjects
tsunami, megablock, sedimentology, radiocarbon dating, bioclasts, legend, Science
Abstract

The pre-colonial history (i.e. before the 16th century) of Tonga and West Polynesia still suffers from major gaps despite significant scientific advances in recent years, particularly in the field of archaeology. By the 14th century, the powerful Tu’i Tonga kingdom united the islands of the Tongan archipelago under a centralised authority and, according to tradition, extended its influence to neighbouring island groups in the Central Pacific. However, some periods of deep crisis were identified, e.g. in the mid- 15th century, marked by an abrupt cessation of inter-archipelago migration on the deep seas in the Pacific, significant cultural changes, and a decrease in accessible natural resources. The origins of these disturbances are still debated, and they are usually assigned to internal political problems or loss of external influence vis-à-vis neighboring chiefdoms. However, the hypothesis of a major natural disaster was rarely suggested up to now, while field evidence points to the occurrence of a very large tsunami in the past, including the presence of numerous megablocks that were deposited by a “red wave” (or peau kula, which also mean tsunami in the Tongan language) according to a local myth. Drawing on a body of new evidence from sedimentary signatures and radiocarbon dating of charcoal and marine bioclasts, geomorphology, and sedimentology, in support of previously published archaeological data, we argue that a large tsunami inundated large areas of Tongatapu island in the mid-15th century with runup heights up to 30 m, and that the Tu’i Tonga kingdom was severely impacted by this event. We also discuss the likely sources of this tsunami.

Published
2021
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2. Die Mehrsprachigkeit im DaF-Unterricht Am Beispiel von multilingualer Sprach- und Textarbeit in den sprachwissenschaftlichen Modulen im Master 1 und 2 an der Univ-Oran

Author

Fatima Mokadem

Subjects
Multilingualism, foreign language, Deutsch acquisition, multilingual text work, didactic and methodical competence, Stylistics, Translating and interpreting, P306-310
Abstract

Multilingualism in Deutschlessons:The case of multilingual language and text work in the linguistic in Masters 1 and 2 units at the Univ-Oran The fact that Algerians grow up multilingual and also acquire other languages simultaneously, successively or in a controlled manner in preschool, elementary school, middle school and high school summarizes the entire linguistic situation in Algeria as well as reality of the Algerian educational system. We would like to show in this paper how this multilingual competence is used in the Deutsch as a foreign language classes among students with advanced levels (Master 1 and 2) through texts analysis in Algerian Arabic, Standard Arabic, Berber, French, English and Deutsch to impart knowledge in the areas of stylistics, discourse analysis and cultural semiotics, and also to analyze and discuss examples from our seminars. We are at some conclusions through this research, specifically that the teacher must react very flexibly to the respective classroom or extra-curricular situation, pay attention to the aspect of Deutsch as a foreign language when teaching technical or linguistic content, carefully select the topics and documents and provide appropriate measures and aids to facilitate language acquisition. As part of the training of our master's students at University of Oran2, research projects are focused on "stylistic analysis of texts in Standard Arabic, Deutsch, French, Berber and Algerian Arabic, discourse analysis, intercultural dimensions of learning in Algeria as well as specialist teaching. This variability allows students to try out the knowledge they have acquired during their training in practice and build up appropriate skills that help them to successfully plan, implement and evaluate flexible bilingual or plurilingual work in Deutsch classes.

Published
2016

3. Der Einsatz vom Film und von Filmsequenzen für einen handlungsorientierten DaF-Unterricht im LMD-Ausbildungssystem an Der Universität Oran

Author

Fatima Mokadem

Subjects
Action orientation, Deutsch calsses, communicative competence, intercultural competence, film stations, German films, Translating and interpreting, P306-310
Abstract

The use of film and film sequences for an action learning in German classes under LMD system at the University of Oran The aim of this article is to undertake a research on the use of German films in Algerian GFL classes. Due to the -constantly growing- globalization, language and cultural knowledge are becoming more important than ever before for individuals and society. If you speak several languages today, you also have more opportunities in professional life. Foreign cultures always come with foreign languages. However, without staying in the countries of the target language, it is very difficult to really get to know the culture. Nevertheless, most Algerian pupils and GFL students will only encounter the foreign language and the foreign culture at school or at university. The teacher in Deutsch lessons becomes a very important element in the transfer of culture, mostly with the support of didactic means (textbooks, films, pictures, textbooks...etc). In doing so, he must observe the basic principles of media didactics, the methods of using the medium of film and the competence goals of the curriculum. So, the focus is directed onto teaching, and what happens in the classrooms determines how well this new culture is conveyed. Using examples from our seminars, we would like to present and analyze some of the methods reinforcing the appeal to the film in order to develop different skills among Algerian GFL learners.

Published
2014

4. Frauenbilder in der Liebeslyrik Bertolt Brechts und Nizar Qabbanis

Author

Fatima Mokadem

Subjects
Translating and interpreting, P306-310
Abstract

Images of women in the love poetry of Bertolt Brecht and Nizar Qabbani The aim of this article is to scientifically and precisely examine the image of women in the language of B. Brecht and N. Qabbani's love poetry, which would allow to identify their similarities and differences. Ultimately, an attempt is made here to identify the cultural parallels between B. Brecht's and N. Qabbani's love poetry, which depicts women. In order to ensure this accuracy in the context of the present contribution and at the same time to present the diversity of the imagination of the female, it is necessary to examine individual images and motives to begin. This contribution aims to analyze the pictorial vocabulary used by Qabbani and Brecht to represent the feminine. At the same time, it is clarified how both poets proceed in the design of feminine patterns using the example of mother, lover and wife, i.e. how they "condense" the found female reality.

Published
2011

5. Zu Bertolt Brechts Sonett „Über Kleists ´Prinz von Homburg´

Author

Fatima Mokadem

Subjects
art-critical sonnets, literary tradition, Heinrich von Kleist's last work, Translating and interpreting, P306-310
Abstract

On Bertolt Brecht's sonnet "About Kleist's 'Prinz von Homburg' In addition to his plays, socio-critical, war and love poems, Bertolt Brecht (b. 1898, died 1956) wrote eight art-critical sonnets. which he called "Studies" and published in 1951 in the 11th issue of "Versuche". These sonnets were written during the exile in the years 1934-1940. Brecht is referring here to classic, mostly literary (both lyrical and dramatic) works whose authors are considered classics in the sense of Brecht. Without exception, the sonnets in question deal with works of the past, more than half of the analyzes in the “Studies” refer to works of the German classics, three of them to those of the Weimar Classic. The "Studies" published in 1951 are not about an overall assessment of a classic work, positive or negative, but about conveying reservations about traditional literary material, which Brecht considers worthy of being examined and looked at again. These include the sonnet "About Kleist's play 'Der Prinz von Homburg'", which refers to the play "Prinz Friedrich von Homburg", which stands at the end of German classicism and which Heinrich von Kleist wrote between 1809 and 1811 as the last work before his suicide Has. In this contribution, which I presented as a lecture at the Humboldt University in Berlin in June 2010, I attempt to carry out a linguistic analysis of this sonnet in three points. First I give a brief overview of the development of Heinrich von Kleist's drama "Der Prinz Friedrich von Homburg", then about the critical sonnets "Studies" by Bertolt Brecht, then historical and socio-critical aspects are explained using examples from B. Brecht's sonnet "Über Kleists' Prince of Homburg'” highlighted.

Published
2010

6. Das Frauenbild in Bertolt Brechts und Nizar Kabbanis Liebeslyrik

Author

Fatima Mokadem

Subjects
Das Frauenbild, die Frauenrolle, die Liebesdichtung B. Brechts und N. Kabbanis, Thematisierung von Frauenwelt, Thematisierung von gesellschaftlichen Tabus., Translating and interpreting, P306-310
Abstract

Das Ziel dieses Beitrags ist das Frauenbild in der Sprache B. Brechts und N. Kabbanis Liebeslyrik zu untersuchen. Hier wird versucht zu identifizieren, inwieweit und in welchem Rahmen sich B. Brecht und N. Kabbani in ihrer Liebeslyrik den Kampf gegen Tabus der Thematisierung von Frauen und die Revolutionierung der Frauenwelt zum Ziel gesetzt haben. Dieser Beitrag verfolgt die Absicht, die Spezifik des Vokabulars zu analysieren.

Published
2009

7. Der Sprachpluralismus und die Sprachpflege in Algerischen Theater: Der Fall des Theaterstückes „El Ajouad' von Abdelkader Alloula

Author

Fatima Mokadem

Subjects
Language maintenance, High standard language, mother tongue, contribution of artists and writers., Translating and interpreting, P306-310
Abstract

Linguistic Pluralism and Language Maintenancein the Algerian theatre: The case of the play "El Ajouad" by Abdelkader Alloula This article is primarily intended as a linguistic contribution within the large and diverse complex of Alloula's research, including literary, linguistic and theater results. Brecht is one of the central figures in international theater history, both as a theater practitioner and playwright and as an important theoretician and aesthetician. He had a strong influence on the German language and had an effect on it. Thanks to this dual competence as a practitioner and a theoretician, Brecht presents an extremely interesting subject of investigation.The well-known Algerian dramaturge Abdelkader Alloula was inspired by Brecht. He said this publicly in a conversation with university teacher and researcher Mhamed Djellid(Oktober 1985 ; 10):“Brecht was and remains a role model in my work through his theoretical writings and his artistic work. I will even say that he is my spiritual father and better still my friend and my faithful companion”.Like Brecht, Abdelakder Alloula worked on the Algerian language so creatively, cultivated it so passionately and nurtured it from the soil of the standard written language. In the piece "El Ajouad" there is a lot to say and also to learn about this language work.

Published
2008

8. Multi-millennial human impacts and climate change during the Maya early Anthropocene: implications on hydro-sedimentary dynamics and socio-environmental trajectories (Naachtun, Guatemala)

Author

Cyril Castanet, Louise Purdue, Marc Testé, Aline Garnier, Anne-Lise Develle-Vincent, Fatima Mokadem, Christine Hatté, Caroline Gauthier, Philippe Lanos, Philippe Dufresne, Eva Lemonnier, Lydie Dussol, Julien Hiquet, Philippe Nondédéo, Université Paris 8 Vincennes-Saint-Denis (UP8), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Culture et Environnements, Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne (UP1), Archéologie des Amériques (ArchAm), Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Petén Norte NAACHTUN (2010–2022, dir. P. Nondédéo, supports: Ministère de l'Europe et des Affaires Etrangères MEAE, Centre National de la Recherche Scientifique CNRS, Université Paris 1 Panthéon-Sorbonne, Pacunam foundation, Perenco company, Simone et Cino Del Duca foundation), MAYANAT (2020–2021, coord. C. Castanet, supports: Institut Écologie et Environnement INEE of the CNRS), HYDROAGRO (2014–2016, coord. E. Lemonnier, C. Castanet, supports: Université Paris 1 Panthéon-Sorbonne)., ANR-11-LABX-0046,Dynamite,Dynamiques Territoriales et spatiales(2011), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Rennes 2 (UR2), and Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Archeology, Global and Planetary Change, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Geology, Central America, [SHS.GEO]Humanities and Social Sciences/Geography, Sedimentology, [SDE.ES]Environmental Sciences/Environmental and Society, Naachtun, Maya, Erosion, Anthropocene, Wetland, Polje, Paleolimnology, Geoarcheology, Hydrology, Bajo, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, Anthropization
Abstract

International audience; During the Maya early Anthropocene (2000 BCE e 1000 CE) in Mesoamerica, socio-environmental in-teractions contributed to the rise and decline of the ancient Maya civilisation. At the scale of the exploitation territories of the Maya cities, the temporal variations of hydrological and sedimentary dynamics in response to anthropogenic and climate drivers are still poorly known. This constrains diachronic analyses of socio-ecosystems and, more particularly, of water and soil resources in the hinterlands. This manuscript analyses and presents a regional comparison of the dynamics of one of the most transformed hydrosystems and morpho-sedimentary systems by the societies of the Southern Maya Lowlands (SMLs), during the second half of the Holocene. It focuses on the lake basin of the polje named El Infierno bajo and its watershed, which was the main water storage area for the Maya city of Naachtun e a large regional capital between 150 and 950 CE e, and which contains many remains of hydraulic and agrarian structures. This integrated palaeolimnological, geoarchaeological and hydrological approach, based on the analyses of morpho sedimentary archives, LiDAR altimetry data and hydrological data, resulted in the construction of hydro-sedimentary baselines (pre- syn- and post-ancient Maya anthropogenic impacts). Currently, the intermittent lake (civale) of this bajo responds to strong seasonal and interannual hydrological variabilities, under climate control. During the past 5500 years, hydro-sedimentary fluctuations were marked by the alternation of seven main hydrological periods (HP),characterised by high and low lake levels (alternately perennial, intermittent and dry lake) and six main erosion and sediment transfer periods (ESTP), marked by strong and low alluvial and colluvial detrital inputs in the lowlands. Anthropogenic and climate forcings have independently or jointly controlled the hydrologic and sedimentary budgets of the lake basin. Lithofacies, depositional processes, accumulation rates and drivers of the anthropogenic detrital inputs – the so-called “Maya clays” –, are analysed and quantified from ∼1500 BCE to ∼1150 CE. It thus reveals one of the longest periods of occupation and exploitation of natural resources of the SMLs, for over 2500 years during the Preclassic, Classic and Post-classic Maya periods. The hydro-sedimentary dynamics in the bajos of the SMLs Elevated Interior Region (EIR), such as El Infierno, enabled the long-term exploitation of water and soil resources for agrarian purposes, thanks to the construction of hydraulic and agrarian palimpsest landscapes shaped by the socio-ecosystems.

Published
2022

9. A 22,000-year tephrostratigraphy record of unidentified volcanic eruptions from Ternate and Tidore islands (North Maluku, Indonesia)

Author

Audrey Faral, Franck Lavigne, Bachtiar W. Mutaqin, Fatima Mokadem, Rahim Achmad, Rohima Wahyu Ningrum, Pierre Lahitte, Danang Sri Hadmoko, Estuning Tyas Wulan Mei, Université Paris Cité (UPCité), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne - UFR Géographie (UP1 UFR08), Université Paris 1 Panthéon-Sorbonne (UP1), Department of Geography, Universitas Gadjah Mada (UGM), Ternate Khairun University Kampus I, and Faculty of Geography, Universitas Gadjah Mada (UGM)

Subjects
Radiocarbon dating, Geophysics, Geochemistry, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Tephrostratigraphy, ComputingMilieux_MISCELLANEOUS, Eruptive history, Caldera
Abstract

Studying past eruptions provides a unique opportunity to improve understanding of volcanic hazards, especially in Indonesia, where volcanic eruptions are frequently deadly and destructive. As part of a recent approach to identifying and characterizing past volcanic events, we present the first reconstruction of the eruptive history of the Ternate and Tidore Islands (North Maluku, Indonesia) for the last 22,000 years cal. BP. This interdisciplinary study (geomorphology, tephrochronology, sedimentology, geochronology, geochemistry) consists of the first stratigraphic and chronological continuum from eruptive deposits established in a set of fifteen sections in Ternate, Tidore and Maitara islands. Sedimentological and geochemical data from tephrostratigraphy studies and radiocarbon dating suggest that these islands experienced at least four major explosive events from c. 22,000 to 740 years cal. BP. The earliest event is a Plinian eruption leading to the caldera formation of Telaga volcano on the island of Tidore, c. 22,000–17,500 cal. BP. The Gamalama volcano on Ternate, whose current eruptive activity is essentially strombolian or phreatomagmatic, experienced as well a pumice eruption dated to c. 18,000 cal BP. A third event dated to c. 14,500-13,000 cal. BP, associated with a succession of abundant pyroclastic deposits of scoria, pumice, and ash, is related with the phreatomagmatic eruption at the origin of the formation of the Ngade maar on Ternate Island. Although no eruptions of Kie Matubu volcano on Tidore Island have been filled out by people since their presence in the region from the 16th century, this survey identifies two late Holocene eruptions, c. 2500 cal BP and 740 cal BP. This chronostratigraphic framework from the late Pleistocene to recent eruptions in North Maluku region provides new perspectives in managing predictive and warning information for potential eruptions that may occur on these small, vulnerable volcanic islands in the future.

Published
2022

10. Nature, exploitation et gestion de la ressource édaphique dans les Basses Terre mayas : cas de l’agrosystème des bajos du territoire de Naachtun au Préclassique et au Classique (Petén, Guatemala)

Author

Cyril Castanet, Amaury Fernandes, Lydie Dussol, Eugénie Dautriche, Aline Garnier, Marc Testé, Julien Cavero, Christine Hatté, Louise Purdue, Anne-Lise Develle-Vincent, Fatima Mokadem, Eva Lemonnier, Gyorgy Sipos, Clement Virmoux, Philippe Nondédéo, Université Paris 8 Vincennes-Saint-Denis (UP8), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Culture et Environnements, Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Université Paris 1 Panthéon-Sorbonne (UP1), Archéologie des Amériques (ArchAm), Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Dussol, Lydie, Université Nice Sophia Antipolis (1965 - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)

Subjects
[SHS.ARCHEO] Humanities and Social Sciences/Archaeology and Prehistory, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, [SDE.ES] Environmental Sciences/Environmental and Society, [SDE.ES]Environmental Sciences/Environmental and Society, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2021

12. The kingdom of Tonga devastated by a megatsunami in the mid-15th century

Author

Fuka Kitekei’aho, Wassmer Patrick, Franck Lavigne, Tu’I’ahai Tu’I’afitu, Faral Audrey, Mukhamad Ngainul Malawani, Céline Vidal, Weller Olivier, Raphaël Paris, Gomez Christopher, Ana V. Maea, Fatima Mokadem, Ségolène Saulnier-Copard, Julie Morin, Karim Kelfoun, Kula Taaniela, and Mhammed Benbakkar

Subjects
Kingdom, History, Ancient history
Abstract

The pre-colonial history of Tonga and West Polynesia still suffers from major gaps because its reconstruction is essentially based on legends left by oral tradition, and by archaeological evidence somehow difficult to interpret. By the fourteenth century, the powerful Tu'i Tonga kingdom united the islands of the Tongan archipelago under a centralised authority and, according to tradition, extended its influence to neighbouring island groups in the Central Pacific. However, some periods of deep crisis were identified, e.g. in the mid- 15th century, marked by an abrupt cessation of inter-archipelago migration on the deep seas in the Pacific, significant cultural changes, and a decrease in accessible natural resources. The origins of these disturbances are still debated, and are usually assigned to internal political problems or loss of external influence vis-à-vis neighboring states. However, the hypothesis of a major natural disaster was never suggested up to now.Drawing on a body of new evidence from sedimentary signatures and radiocarbon dating of charcoal and marine bioclasts, geomorphology, and sedimentology, in support of previously published archaeological data, we argue that the Tu’i Tonga kingdom was severely impacted by a megatsunami in the mid-15th century. We also discuss the likely sources of this event, which happened in an isolated region of the world before the European maritime “great discoveries”. This tsunami could be the source of vivid local myths that strongly suggest that a giant wave covered almost the entire island of Tongatapu at one time.

Published
2021

13. Evolution of a debris-covered glacier in the Kerguelen Archipelago (49°S, 69°E) over the past 15,000 years constrained by in situ cosmogenic 36Cl dating

Author

Irene Schimmelpfennig, Vincent Favier, Joanna Charton, Vincent Jomelli, Fatima Mokadem, Fanny Brun, Didier Bourlès, Georges Aumaître, Karim Keddadouche, Deborah Verfaillie, and Adrien Gilbert

Subjects
In situ, geography, geography.geographical_feature_category, Archipelago, Glacier, Physical geography, Debris, Geology
Abstract

Debris-covered glaciers constitute a substantial part of the worldwide cryosphere (Scherler et al. 2018). However, their long-term response to multi-millennial climate variability has rarely been studied, in particular in the Southern Hemisphere. The presence of both debris-covered and debris-free glaciers on Kerguelen Archipelago (49°S, 69°E) offers therefore an excellent opportunity to investigate and compare long-term evolution of these two types of glaciers. To do so, we used the cosmogenic 36Cl surface dating method on moraine boulders that allows to establish temporal constraints of glacier oscillation. We provide here the first Late Glacial and Holocene glacier chronology of a still active debris-covered glacier from the archipelago: the Gentil Glacier. Results show that the Gentil Glacier advanced once at ~14.3 ka, i.e. during the Late Glacial (19.0 – 11.6 ka), and re-advanced during the Late Holocene at ~2.6 ka (Charton et al., 2020). Both debris-covered and debris-free glaciers experienced a broadly synchronous advance during the Late Glacial, that may be assigned to the Antarctic Cold Reversal event (14.5 – 12.9 ka) (Jomelli et al., 2017; 2018). This suggests that both types (debris-covered and debris-free) of glaciers at Kerguelen were sensitive to large amplitude temperature fluctuations recorded in Antarctic ice cores (WAIS divide Project Members, 2013), associated with increased precipitations (Van der Putten, 2015). However, during the Late Holocene, the advance at about ~2.6 ka was not observed on other glaciers and seems to be a specific response of the debris-covered Gentil Glacier, either related to distinct ice dynamics or an individual response to precipitation changes. Charton et al., 2020 : Ant. Sci. 1-13Jomelli et al., 2017 : Quat. Sci. Rev. 162, 128-144Jomelli et al., 2018 : Quat. Sci. Rev. 183, 110-123Scherler et al., 2018 : GRL. 45, 11,798-11,805Van der Putten et al., 2015 : Quat. Sci. Rev. 122, 142-157WAIS Divide Project Members, 2013: Nature. 500, 440-444

Published
2021

14. Dynamics and sustainability of the Maya socio-ecosystem of the hinterland of Naachtun, between 1500 BCE and 1000 CE (Southern Maya Lowlands, Petén, Guatemala)

Author

Philippe Lanos, Hemmamuthé Goudiaby, Julien Hiquet, Antoine Dorison, Cyril Castanet, Nicole Limondin-Lozouet, Aline Garnier, Sandrine Grouard, Lydie Dussol, Louise Purdue, Anne-Lise Develle-Vincent, Fatima Mokadem, György Sipos, Noémie Tomadini, Marc Testé, Carlos Morales-Aguilar, Eva Lemonnier, Christine Hatté, Philippe Nondédéo, and Julien Cavero

Subjects
Geography, Agroforestry, Sustainability, Maya, Ecosystem
Abstract

In the Southern Maya Lowlands (SML), several scientific and technical obstacles hinder the knowledge of environmental and socio-environmental dynamics, that have occurred at the scale of the territories of the cities. This includes the research topic itself (nature-culture interface), the tropical forest (morphological studies and access to the field) and the morphological and sedimentary archives (taphonomy and discontinuity). The study of the socio-ecosystem of Naachtun (150-950 CE), a Maya city of the Classic period, is not exempt from these constraints. Recently, large-scale work in SML was conducted based on LiDAR analyses and fieldwork. They have profoundly renewed our knowledge of the complexity of landscape transformation and natural environments through the action of the ancient Maya (Canuto et al. 2018). They have provided new research perspectives which allow us to examine the following questions.How did natural resource availability (water, soil and biological resources) change in the territory of the city, with respect to climate change and social demand? How did the ancient Maya adapt their resource management strategies to these changes? How important were socio-environmental risks to the resilience and sustainability of the socio-ecosystem? In order to answer these questions, a new systemic, interdisciplinary and multiscalar research program has been implemented. It includes geoarchaeology (alluvial and agrarian), archaeogeography (LiDAR analysis, spatial analysis), palaeoecology and bioarchaeology [archaeobotany (study of phytoliths, anthrocology, pedoanthracology) zooarchaeology (vertebrate and conchyological fauna remains)], spatial archaeology (agglomeration processes, power relays), palaeodemography and geochronology (14C, OSL). Current and pre-anthropic reference frames (hydrological, pedological and ecological) have also been established.Our results reaveal the complexity of the Maya palimpsest territories produced during the ~ 1500 BCE - 1000 CE period (Preclassic and Classic periods). Hydrosedimentary flows have fluctuated in response to climate change and anthropogenic impacts, controlling the spatiotemporal dynamics of resources (water and soils). Lake levels and erosion have fluctuated according to pluricentennial-scale periods. All compartments of the hydrosystem and the sediment system were subject to transformations, to manage water and soils. A mosaic of agricultural and agroforestry strategies was developed throughout the micro-region (morphologies, practices, cropping systems, fuel economy). Intensive wetland systems and irrigated farming systems were established in poljes, sinkholes and valleys (raised fields and drained fields). In addition, in the hilly areas, agrarian systems based on terraced agriculture, rain-fed farming systems, slash-and-burn, arboriculture and horticulture systems were established. The Maya socio-ecosystem which emerged in this micro-region lasted for more than 2500 years. It experienced shits and continuities and its dynamics are framed around six main multi-secular periods. Its decline was part of the profound changes that took place in the territories of the SML cities between 750 and 1050 CE. The sustainability of this socio-ecosystem during the demographic peak of the Late and Terminal Classic (750-950 CE), before the abandonment of the epicenter of the city of Naachtun (~950 CE), is estimated and discussed in relation to the environmental carrying capacity, social demand, climate and its own resilience.

Published
2021

15. Stratigraphy - Sédimentologie

Author

Bertrand Kervazo, Catherine Ferrier, Michel Fialin, Frédéric Maksud, Fatima Mokadem, Jean-François Pastre, Bernard Gély, Evelyne Debard, Sébastien Nomade, Nicolas Rividi, Ségolène Saulnier-Copard, LGP CNRS - UMR8591 Laboratoire de Géographie Physique - Environnements Quaternaires et Actuels, De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Centre de Microanalyse Camparis-CNRS, Université Paris 6, Université Pierre et Marie Curie - Paris 6 (UPMC), DRAC Auvergne-Rhône-Alpes, Direction régionale des affaires culturelles Occitanie (DRAC Occitanie), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Plateforme Camparis - Plateforme analytique MEN (Microanalyses en sciences de l’Environnement) [Paris], Observatoire des sciences de l'univers Ecce Terra [Paris] (OSU ECCE TERRA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Observatoire des sciences de l'univers Ecce Terra [Paris] (ECCE TERRA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Basalt, 010506 paleontology, geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, Pleistocene, Cryptotephra, Geochemistry, Upper Pleistocene, 01 natural sciences, Chauvet-Pont d'Arc cave, Bas-Vivarais volcanism, Maar, Cave, [SDU]Sciences of the Universe [physics], Phreatomagmatic eruption, Upper Paleolithic, General Earth and Planetary Sciences, Tephra, Aurignacian, Geology, 0105 earth and related environmental sciences, General Environmental Science, Phreatomagmatism
Abstract

International audience; A cryptotephra belonging to the Upper Pleistocene volcanism of the Bas-Vivarais was identified for the first time in the sedimentary infilling of the entrance area of the Chauvet-Pont d'Arc cave. This slightly reworked tephra fall is characterized by its heavy minerals assemblage, among which magnesian olivine, enstatite, and chromian diopside issued from peridotites and olivine and diopside of basaltic origin. This composition likely refers to a phreatomagmatic eruption of a maar-crater. The 14 C datings of the cryptotephra beds are contemporaneous with the Aurignacian settlement and paintings, that is, an age slightly older or close to 36 ka. Among the maar-craters from the Bas-Vivarais, the Ray-Pic maar have the closest 40 Ar/ 39 Ar age (36.2 ± 11.3 / 32.2 ± 11.1 ka). By contrast, the Vestide-du-Pal, the biggest maar-crater of this country, seems to have a younger age, but the 40 Ar/ 39 Ar dating was measured on a basalt which could have occurred later and been the source of the tephra-fall, since its tephras contain the same minerals of unknown origin as those found in Chauvet Cave. This discovery strengthens the previous hypothesis according to which the humans living in the Chauvet-Pont d'Arc area during the Upper Paleolithic have witnessed eruptions from the Bas-Vivarais volcanic field and other phenomena.

Published
2021

16. Nature et dynamique du socio-écosystème maya du territoire de subsistance de la cité de Naachtun entre 1500 BCE et 1000 CE (Petén, Guatemala)

Author

Cyril Castanet, Philippe Nondédéo, Lydie Dussol, Marc Testé, Louise Purdue, Julien Hiquet, Eva Lemonnier, Aline Garnier, Antoine Dorison, Noémie Tomadini, Sandrine Grouard, Hemmamuthé Goudiaby, Carlos Morales Aguilar, Nicole Limondin-Lozouet, Julien Cavero, Anne-Lise Develle-Vincent, Christine Hatté, Caroline Gauthier, Philippe Lanos, Fatima Mokadem, György Sipos, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), and Nondédéo, Philippe

Subjects
[SHS.ENVIR] Humanities and Social Sciences/Environmental studies, [SHS.ENVIR]Humanities and Social Sciences/Environmental studies, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2021

17. Volcanic risks on Ternate and Tidore islands (North Maluku, Indonesia)

Author

Audrey Faral, Franck Lavigne, Bachtiar Mutaqin, Fatima Mokadem, Rahim Achmad, Pierre Lahitte, Danang Sri Hadmoko, Estuning Tyas Wulan Mei, and Faral, Audrey

Subjects
[SDU.STU.GM] Sciences of the Universe [physics]/Earth Sciences/Geomorphology, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology
Published
2021

19. A debris-covered glacier at Kerguelen (49°S, 69°E) over the past 15 000 years

Author

Georges Aumaître, Vincent Favier, Vincent Jomelli, Didier Bourlès, Joanna Charton, Adrien Gilbert, Irene Schimmelpfennig, Karim Keddadouche, Fanny Brun, Deborah Verfaillie, Fatima Mokadem, Université Paris 1 Panthéon-Sorbonne (UP1), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Catholique de Louvain = Catholic University of Louvain (UCL), Université Grenoble Alpes (UGA), French INSU LEFE Glacepreker project, IPEV Kesaaco 1048 project, and ANR-11-LABX-0046,Dynamite,Dynamiques Territoriales et spatiales(2011)

Subjects
010504 meteorology & atmospheric sciences, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, glacier fluctuations, Antarctic Cold Reversal, in situ cosmogenic chlorine-36 dating, Ice core, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Paleoclimatology, paleoclimate, Cryosphere, Glacial period, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, sub-Antarctic, Geology, Glacier, 13. Climate action, Moraine, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Physical geography
Abstract

ASTER Team: Georges Aumaître, Didier L. Bourlès and Karim Keddadouche; International audience; Debris-covered glaciers constitute a large part of the world's cryosphere. However, little is known about their long-term response to multi-millennial climate variability, in particular in the Southern Hemisphere. Here, we provide first insights into the response of a debris-covered glacier to multi-millennial climate variability in the sub-Antarctic Kerguelen Archipelago, which can be compared to that of recently investigated debris-free glaciers. We focus on the Gentil Glacier and present thirteen new 36 Cl cosmic-ray exposure ages from moraine boulders. The Gentil Glacier experienced at least two glacial advancesthe first one during the Late Glacial (19.0-11.6 ka) at ~14.3 ka and the second one during the Late Holocene at ~2.6 ka. Both debris-covered and debris-free glaciers advanced broadly synchronously during the Late Glacial, most probably during the Antarctic Cold Reversal event (14.5-12.9 ka). This suggests that both glacier types at Kerguelen were sensitive to abrupt temperature changes recorded in Antarctic ice cores, associated with increased moisture. However, during the late Holocene, the advance at about ~2.6 ka was not observed in other glaciers and seems to be an original feature of the debris-covered Gentil Glacier, either related to distinct dynamics or distinct sensitivity to precipitation changes.

Published
2021

20. Dynamique du socio-écosystème maya du territoire de subsistance de la cité de Naachtun (Petén, Guatemala) entre 1500 av. et 1000 apr. J.-C. Développements méthodologiques et résultats préliminaires d'une approche systémique multiscalaire

Author

Cyril Castanet, Philippe Nondédéo, Lydie Dussol, Marc Testé, Louise Purdue, Julien Hiquet, Eva Lemonnier, Aline Garnier, Hemmamuthé Goudiaby, Antoine Dorison, Noémie Tomadini, Carlos Morales Aguilar, Nicole Limondin-Lozouet, Julien Cavero, Anne-Lise Develle-Vincent, Christine Hatté, Philippe Lanos, Fatima Mokadem, György Sipos, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Université Paris 8 Vincennes-Saint-Denis - Département de Géographie, Université Paris 8 Vincennes-Saint-Denis (UP8), Archéologie des Amériques (ArchAm), Université Paris 1 Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Culture et Environnements, Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Archéozoologie, archéobotanique : sociétés, pratiques et environnements (AASPE), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géochrononologie Traceurs Archéométrie (GEOTRAC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Géosciences Rennes (GR), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), University of Szeged [Szeged], Collège international des sciences territoriales (CIST), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)

Subjects
territoire, Resilience, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Socio-ecosystem, risques, [SHS.GEO]Humanities and Social Sciences/Geography, [SHS.ANTHRO-SE]Humanities and Social Sciences/Social Anthropology and ethnology, socio-écosystème, Resources, résilience, [SHS]Humanities and Social Sciences, ressources, Maya, [SDE]Environmental Sciences, Risks, Territory
Abstract

International audience; In the centre of the Mayan Lowlands, several scientific and technical obstacles hinder the understanding of long-term socio-environmental dynamics, at the scale of the territories of the cities. The study of the socio-ecosystem of Naachtun, a Maya city of the Classic period, is not exempt from these constraints. How did natural resources (water, soil and living resources) along with management strategies change, in the past in the territory of this city, with special respect to climate, social demands and relation with nature of the ancient Mayas? What were the associated socio-environmental risks and how did the resilience of the socio-ecosystem change? In order to answer these questions by removing these obstacles, new systemic, interdisciplinary and multiscalar, methodological research is being implemented (geoarchaeology, archaeogeography, palaeoecology, archaeobotany, archaeozoology and geochronology). Preliminary results reveal the complexity of the Mayan palimpsest territories produced during the ~ 1500 BCE-1000 CE period and inform the cross dynamics of hydrosystems, agrosystems and sociosystems.; Dans le cœur des Basses Terres mayas, plusieurs verrous scientifiques et techniques constituent des obstacles à la connaissance des dynamiques socio-environnementales, survenues aux échelles des territoires des cités sur la longue durée. L’étude du socio-écosystème de Naachtun, cité maya de la période Classique, n’échappe pas à ces contraintes. Quelles furent les évolutions des ressources (eau, sol et vivant) et de leurs gestions dans ce territoire, en regard du climat, de la demande sociale et du rapport à la nature des anciens Mayas? Quels furent les risques socio-environnementaux associés à ces évolutions ainsi que la résilience du socio-écosystème? Afin de répondre à ces questions en levant ces obstacles, de nouveaux développements méthodologiques systémiques, interdisciplinaires et multiscalaires sont mis en œuvre (géoarchéologie, archéogéographie, paléoécologie, archéobotanique, archéozoologie, archéologie et géochronologie). Les résultats préliminaires révèlent la complexité des territoires palimpsestes mayas produits durant l’épisode ~ 1500 av.-1000 apr. J.-C. et renseignent les dynamiques croisées des hydrosystèmes, des agrosystèmes et des socio-systèmes.

Published
2020

21. The procurement of obsidian at Arslantepe (Eastern Anatolia) during the Chalcolithic and Early Bronze Age: Connections with Anatolia and Caucasus

Author

Giulio Palumbi, Bernard Gratuze, Marcella Frangipane, Fatima Mokadem, M. Massussi, Ebru Akköprü, Anne-Kyria Robin, Damase Mouralis, F. Balossi Restelli, Daniel Brunstein, Identité et Différenciation de l’Espace, de l’Environnement et des Sociétés (IDEES), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire Homme et Société (IRIHS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Lieux, Identités, eSpaces, Activités (LISA), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), IRAMAT - Centre Ernest Babelon (IRAMAT-CEB), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Identités et Différenciation de l'Environnement des Espaces et des Sociétés (IDEES), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Institut de Recherche Interdisciplinaire Homme et Société (IRIHS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), and Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)

Subjects
Obsidian, 010506 paleontology, Caucasus, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, Obsidian, Arslantepe, Eastern Anatolia, Caucasus, Portable XRF, LA-ICP-MS, 01 natural sciences, Sequence (geology), Procurement, Bronze Age, 0601 history and archaeology, 0105 earth and related environmental sciences, Earth-Surface Processes, Middle East, Preferential choice, [SHS.STAT]Humanities and Social Sciences/Methods and statistics, 060102 archaeology, Portable XRF, 06 humanities and the arts, Chalcolithic, [SHS.GEO]Humanities and Social Sciences/Geography, Arslantepe, Archaeology, [SDE.ES]Environmental Sciences/Environmental and Society, Eastern Anatolia, Geography, Large group
Abstract

International audience; Arslantepe is a höyük (= tell) located within the fertile Malatya Plain, near the right bank of the Euphrates River. The site is excavated since more than 55 years by the Italian Sapienza University archaeologists and reveals periods from at least the sixth millennium BCE until the final destruction of the Neo-Hittite town. This long sequence records the changing relations and connections with various civilizations and regions of the Near East. Using the chemical characterization of a large group of artefacts (388 analysed), we propose, in this paper, a new sourcing of the obsidian used by the inhabitants of Arslantepe from the beginning of the Late Chalcolithic to the end of the Early Bronze Age. The method is based on the portable XRF analyse of the artefacts and their attribution to a geological source using our database collected within the ongoing " GeObs " project (resp. D. Mouralis) in the Eastern Anatolia as well as previous published data in Central Anatolia and Caucasus. Moreover, the chemical characterization is coupled with the techno-functional determination of the artefacts. The present study conducted by an interdisciplinary research group allows to precise the procurement of obsidian in Arslantepe and to better understand the external relations of the site over time. This research also questions and discusses the preferential choice of the obsidian sources through time, in relation with various factors such as distance, quality and abundance of the raw material as well as socio-cultural influences.

Published
2018

22. Glacier extent in sub-Antarctic Kerguelen archipelago from MIS 3 period: Evidence from 36Cl dating

Author

Vincent Favier, Amaelle Landais, Vincent Jomelli, Fatima Mokadem, Claude Legentil, Deborah Verfaillie, Didier Bourlès, Daniel Brunstein, Irene Schimmelpfennig, Georges Aumaître, Karim Keddadouche, Vincent Rinterknecht, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut des Géosciences de l’Environnement (IGE), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Lieux, Identités, eSpaces, Activités (LISA), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Unité de Recherche Great Ice, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), DEES, University of St Andrews [Scotland], Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )

Subjects
Archeology, 010504 meteorology & atmospheric sciences, MIS 2-4, Antarctic ice sheet, 010502 geochemistry & geophysics, 01 natural sciences, Kerguelen, Antarctic Cold Reversal, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Deglaciation, 36Cl cosmic-ray exposure dating, 14. Life underwater, Glacial period, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, Geology, Glacier, Last Glacial Maximum, Glacier fluctuations, 13. Climate action, Moraine, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Archipelago, Physical geography
Abstract

International audience; Documenting sub-Antarctic glacier variations during the local last glacial maximum is of major interest to better understand their sensitivity to atmospheric and oceanic temperature changes in conjunction with Antarctic ice sheet changes. However, data are sparse because evidence of earlier glacier extents is for most sub-Antarctic islands located offshore making their observation complex. Here, we present 22 cosmogenic 36Cl surface exposure ages obtained from five sites at Kerguelen to document the glacial history. The 36Cl ages from roche moutonnee surfaces, erratics and boulders collected on moraines span from 41.9 ± 4.4 ka to 14.3 ± 1.1 ka. Ice began to retreat on the eastern part of the main island before 41.4 ± 4.4 ka. Slow deglaciation occurred from ∼41 to ∼29 ka. There is no evidence of advances between 29 ka and the Antarctic Cold Reversal (ACR) period (∼14.5–12.9 ka) period. During the ACR, however, the Bontemps and possibly Belvedere moraines were formed by the advance of a Cook Ice Cap outlet glacier and a local glacier on the Presque Ile Jeanne d’Arc, respectively. This glacier evolution differs partly from that of glaciers in New Zealand and in Patagonia. These asynchronous glacier changes in the sub-Antarctic region are however in agreement with sea surface temperature changes recorded around Antarctica, which suggest differences in the climate evolution of the Indo-Pacific and Atlantic sectors of Antarctica.

Published
2018

23. Reassessing the stable (δ88/86Sr) and radiogenic (87Sr/86Sr) strontium isotopic composition of marine inputs

Author

Ian J. Parkinson, Christopher R. Pearce, Kevin W. Burton, Fatima Mokadem, Jérôme Gaillardet, Bruce L. A. Charlier, Department of Earth and Environmental Sciences [Milton Keynes], The Open University [Milton Keynes] (OU), University of Bristol [Bristol], Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences [Durham], Durham University, and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Strontium, Radiogenic nuclide, Geochemistry, chemistry.chemical_element, Mineralogy, Weathering, [SHS.GEO]Humanities and Social Sciences/Geography, strontium isotope, Isotopes of strontium, Diagenesis, chemistry.chemical_compound, chemistry, 13. Climate action, Geochemistry and Petrology, Enhanced weathering, Carbonate, Seawater, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, Geology
Abstract

The stable strontium isotope system (δ88/86Sr) has recently been suggested to be a suitable proxy for determining variations in the strength of the marine carbonate system, the principal output flux of oceanic Sr. However, in order to be able to interpret carbonate-driven variations in δ88/86Srseawater a robust understanding of δ88/86Srinput is required. Surprisingly only a limited amount of δ88/86Sr data currently exists for rivers and hydrothermal fluids, thus this study assesses the variability of δ88/86Sr and 87Sr/86Sr in global rivers, hydrothermal fluids and porewaters, as well as minor marine Sr sources such as continental dust, rainwater and glacial ice. Our analyses broadly confirm the findings of Krabbenhoft et al. (2010), and reveal flux-weighted δ88/86Srriverine and 87Sr/86Srriverine compositions of 0.32‰ and 0.71299 respectively. The hydrothermal fluids analysed in this study are consistent with an end-member δ88/86Srhydrothermal composition that is the same as the oceanic crust at ∼0.24‰, although three samples that display δ88/86Sr compositions offset from the seawater-hydrothermal mixing trend suggest that the precipitation of alteration phases such as anhydrite may drive δ88/86Srhydrothermal to higher values. Porewater fluids obtained from sediment cores in the Atlantic and Pacific Oceans have δ88/86Sr compositions within error of seawater (0.39‰), implying that the diagenetic flux of Sr may not significantly affect the δ88/86Sr composition of seawater. Continental loess samples have δ88/86Sr compositions that are consistently lighter than, or equal to, terrestrial silicates, with their tendency to lower values thought to reflect the preferential removal of heavier Sr isotopes into solution during weathering. Finally, rainwater and glacial ice samples have δ88/86Sr compositions that are also isotopically lighter than their associated water sources, a factor that may be attributed to interaction with isotopically light loess and additional Sr contributions from the bedrock. Together, the principal marine inputs define flux-weighted oceanic δ88/86Srinput and 87Sr/86Srinput compositions of 0.32‰ and 0.71161. These values are consistent with an elevated supply of riverine Sr to the oceans due to increased post-glacial weathering, but require the enhanced weathering of exposed carbonate shelves during glacial periods or significant changes in the rate of carbonate burial to match observed changes in the 87Sr/86Sr ratio of seawater. Our results confirm that, providing a diagenetically robust proxy can be found, the δ88/86Sr and 87Sr/86Sr isotope systems should provide a useful proxy for investigating changes in the marine carbonate system through time.

Published
2015

24. Sub-Antartic glacier extensions in the Kerguelen region (49° S, Indian Ocean) over the past 24 000 years constrained by 36Cl moraine dating

Author

Georges Aumaître, Irene Schimmelpfennig, Vincent Jomelli, Fatima Mokadem, Didier Bourlès, Didier Swingedouw, Karim Keddadouche, Vincent Favier, Claude Legentil, Emmanuel Chapron, Deborah Verfaillie, Vincent Rinterknecht, Elisabeth Michel, Alain Jaouen, Daniel Brunstein, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Géographie de l'environnement (GEODE), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Biogéosystèmes Continentaux - UMR7327, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Paléocéanographie (PALEOCEAN), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), L'Institut polaire français Paul-Emile Victor (IPEV), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), CNRS-INSU, ANR-10-EQPX-0024,ASTER-CEREGE,PLATEFORME DE GEOCHIMIE ISOTOPIQUE ASTER/CEREGE(2010), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), ANR-10-EQPX-0024/10-EQPX-0024,ASTER-CEREGE,PLATEFORME DE GEOCHIMIE ISOTOPIQUE ASTER/CEREGE(2010), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut de Recherche pour le Développement (IRD)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)

Subjects
Archeology, 010504 meteorology & atmospheric sciences, 36 cl cosmic-ray exposure dating, Climate change, 010502 geochemistry & geophysics, 01 natural sciences, Kerguelen, Ice core, Deglaciation, 36Cl cosmic-ray exposure dating, 14. Life underwater, Glacial period, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, Geology, Last Glacial Maximum, Glacier, Glacier fluctuations, [SHS.GEO]Humanities and Social Sciences/Geography, Oceanography, 13. Climate action, Moraine, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, [SDU]Sciences of the Universe [physics], late glacial
Abstract

International audience; Similar to many other regions in the world, glaciers in the southern sub-polar regions are currently retreating. In the Kerguelen Islands (49°S, 69°E), the mass balance of the Cook Ice Cap (CIC), the largest ice cap in the region, experimented dramatic shrinking between 1960 and 2013 with retreat rates among the highest in the world. This observation needs to be evaluated in a long-term context. However, data on the past glacier extents are sparse in the sub-Antartic regions. To investigate the deglaciation pattern since the Last Glacial Maximum (LGM) period, we present the first 13 cosmogenic 36Cl surface exposure ages from four sites in the Kerguelen Islands. The 36Cl ages from erratic and moraine boulders span from 24.4±2.7 ka to 0.3±0.1 ka. We combined these ages with extisting glacio-marine radiocarbon ages and bathymetric data to document the temporal and spatial changes of the island's glacial history. Ice began to retreat on the main island before 24.4±2.7 ka until around the time of the Antartic Cold Reversal (ACR) period (-14.5-12.9 ka), during which the Bontemps moraine was formed by the advance of a CIC outlet glacier. Deglacication continued during the Holocene probably until 3 ka with evidence of miror advances during the last millennium. This chronology is in pace with majeor changes in the ᵟ18O in a recent West Antartica ice core record, showing that Kerguelen Islands glaciers are particularly sensitive and relevant to document climate change in the southern polar regions.

Published
2017

25. 10Be cosmic-ray exposure dating of moraines and rock avalanches in the Upper Romanche valley (French Alps): Evidence of two glacial advances during the Late Glacial/Holocene transition

Author

Vincent Rinterknecht, Fatima Mokadem, Melody Biette, Laëtitia Léanni, Marie Chenet, V. Robert, Daniel Brunstein, Erwan Roussel, Vincent Jomelli, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géographie Physique et Environnementale (GEOLAB), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut Polytechnique des Sciences Avancées (IPSA), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Centre National de la Recherche Scientifique (CNRS)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne (UCA), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris 1 Panthéon-Sorbonne (UP1), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne (UCA)-Institut Sciences de l'Homme et de la Société (IR SHS UNILIM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)

Subjects
010506 paleontology, Archeology, 10Be cosmic-ray exposure dating, 010504 meteorology & atmospheric sciences, 01 natural sciences, Allerød oscillation, Paleontology, Deglaciation, Younger Dryas, Glacial period, French Alps, Geomorphology, Ecology, Evolution, Behavior and Systematics, Holocene, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Global and Planetary Change, geography, geography.geographical_feature_category, Geology, Glacier, Glacier fluctuations, [SHS.GEO]Humanities and Social Sciences/Geography, U-shaped valley, Late Glacial, 13. Climate action, Moraine
Abstract

Cosmic-ray exposure (CRE) dating of moraines allow glacier fluctuations and past climate change reconstructions. In the French Alps, there is a lack of moraine dating for the Late Glacial/Holocene transition period. Here we present a chronology of glacier advances in the Upper Romanche valley (French Alps – Massif des Ecrins) based on 10 Be CRE dating. CRE ages of moraines of 13.0 ± 1.1 ka and 12.4 ± 1.5 ka provide evidence for two stages of glacial advance or standstill at the end of the Late Glacial. The CRE dating of a rock avalanche deposit at 12.2 ± 1.5 ka is attributed to post-glacial debuttressing and reveals rapid deglaciation at the end of the Late Glacial. A CRE age of 7.1 ± 0.7 ka of a second mass-wasting, whose triggering factor is unidentified so far, indicates that up to an altitude of 2300 m a.s.l., the valley was ice-free as of ∼7 kyr at the latest. The re-evaluation of 21 moraine 10 Be CRE ages from nine glacial valleys across the Alps shows multiple glacial advances occurring at the Late Glacial/Holocene transition. These results lead to a re-evaluation of the importance of cooling events during the Allerod and the Younger Dryas in the Alps.

Published
2016

26. Arslantepe (Eastern Anatolia) : procurement of obsidian from Anatolian geological sources during the Chalcolithic and Middle Bronze Age

Author

Damase Mouralis, Massimo Massussi, Ebru Akköprü, Francesca Balossi, Korhan Erturaç, Delphine Grancher, Bernard GRATUZE, Fatima Mokadem, Catherine Kuzucuoğlu, Giulio Palumbi, Anne-Kyria Robin, Université d'Orléans, SCD, Identités et Différenciation de l'Environnement des Espaces et des Sociétés (IDEES), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Institut de Recherche Interdisciplinaire Homme et Société (IRIHS), Normandie Université (NU)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], Yüzüncü Yıl University, Van, Turkey, University of Sakarya, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), IRAMAT - Centre Ernest Babelon (IRAMAT-CEB), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Montaigne-Université de Technologie de Belfort-Montbeliard (UTBM), ARCHEORIENT - Environnements et sociétés de l'Orient ancien (Archéorient), Université Lumière - Lyon 2 (UL2)-Centre National de la Recherche Scientifique (CNRS), IAOS International Association for Obsidian Studies, Regional Aeolian Archaeological Museum 'Luigi Bernabò Brea', Identité et Différenciation de l’Espace, de l’Environnement et des Sociétés (IDEES), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire Homme et Société (IRIHS), Normandie Université (NU), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire Homme et Société (IRIHS), and Normandie Université (NU)-Université de Caen Normandie (UNICAEN)

Subjects
Obsidian, Bronze Age, Eastern Anatolia, [SHS.ARCHEO] Humanities and Social Sciences/Archaeology and Prehistory, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, [CHIM] Chemical Sciences, [CHIM]Chemical Sciences, Geochemical analyses, LA-ICP-MS, Chalcolithic
Abstract

International audience; Arslantepe is a höyük (i.e. tell), located within the fertile Malatya Plain, some 12 km from the right bank of the Euphrates River. The long sequence of the site covers several millennia, from at least the 6thmillennium B.C. until the final destruction of the Neo-Hittite town. The archaeological site benefits of a more than fifty years of excavations by the Italian Archaeological Mission (La Sapienza University, Rome). Its long history reflects the changing relations and connections with various civilizations in the Near East (Frangipane 2011). During the earliest phases (Chalcolithic), Arslantepe is connected with the Syro-Mesopotamian world. However, during the Early Bronze Age Arslantepe‘s external relations are reoriented towards eastern Anatolia and Transcaucasia. During these periods, Arslantepe also had connections with Central Anatolia that grow during the 2ndmillennium B.C. with the rising Hittite civilization.This talk focuses on the sourcing of obsidian artifacts collected in Arslantepe. Four hundred artifacts, belonging to eight archaeological levels, from Late Chalcolithic to Middle Bronze Age, were analyzed. These analyzes include technological and typological study together with geochemistry using a portable XRF analyzer. The geochemical data have then been compared with the GeObs database which includes more than 600 geological samples, precisely positioned within space (latitude and longitude) and time (according to volcanic and stratigraphic settings).This database includes 14 sources (i.e. volcanoes) and 34 sub-sources (outcrops with specific volcanic settings) from the Anatolian volcanoes. This talk has three main scopes: 1) studying how the procurement of obsidian change according to the technological and typological kinds of artifacts; 2) understanding the changing external relations through time on obsidian procurement, using the very clear archaeological stratigraphy revealed at the Arslantepe; and 3) showing whether the obsidian procurement indicates same spatial and social connections than other artifacts; and presenting when the obsidian procurement show some different patterns.

Published
2016

27. Unradiogenic lead in Earth’s upper mantle

Author

Olivier Alard, Kevin W. Burton, Jason Harvey, Abdelmouhcine Gannoun, Ian J. Parkinson, Fatima Mokadem, Bénédicte Cenki-Tok, Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU), Dynamique de la Lithosphere, Géosciences Montpellier, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Manteau et Interfaces, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Radiogenic nuclide, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Continental crust, Geochemistry, Volcanology, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 13. Climate action, General Earth and Planetary Sciences, Structural geology, Seabed, Geology, 0105 earth and related environmental sciences
Abstract

International audience; The mantle and continental crust--Earth's main silicate reservoirs--have a lead isotope composition that is too radiogenic to have evolved from primitive Solar System material over 4.57 billion years1. To account for this imbalance, it has been suggested that unradiogenic lead may have partitioned into the metallic core2, 3, 4 or lower continental crust5. Alternatively, radiogenic lead could have been added to Earth later by meteorite impacts6. Unradiogenic lead was discovered in fragments of mantle rocks exhumed in the Horoman massif, Japan, implying that the mantle itself may provide a complementary reservoir of unradiogenic lead7. However, it is unclear why this unradiogenic component is not sampled by the melting that generates oceanic basalts8. Here we present double-spike lead isotope data for abyssal peridotite rocks, considered to represent suboceanic mantle, exposed on the Atlantic Ocean floor. We find that sulphides dated at about 1.83 billion years old and trapped as inclusions in silicate minerals preserve extremely unradiogenic lead isotope compositions. This unradiogenic lead could have been prevented from adding significantly to oceanic basalts if either the silicates shield the sulphide inclusions or if the sulphides reside in refractory mantle rocks that are rarely sampled during melting. We conclude that the lead isotope composition of the silicate Earth could be largely balanced by unradiogenic lead in sulphide in the mantle.

Published
2012

28. Controls on stable strontium isotope fractionation in coccolithophores with implications for the marine Sr cycle

Author

Kevin W. Burton, Jonathan J. Tyler, Rosalind E. M. Rickaby, Emily I. Stevenson, Fatima Mokadem, Ian J. Parkinson, Fabrice Minoletti, Michaël Hermoso, Department of Earth Sciences [Oxford], University of Oxford [Oxford], Department of Earth and Environmental Sciences [Ann Arbor], University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, School of Earth and Environmental Sciences [Adelaide], University of Adelaide, Institut des Sciences de la Terre de Paris (iSTeP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), University of Bristol [Bristol], Department of Earth Sciences [Durham], Durham University, and University of Oxford

Subjects
Calcite, 010504 meteorology & atmospheric sciences, Isotope, biology, Coccolithophore, Mineralogy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Fractionation, 010502 geochemistry & geophysics, biology.organism_classification, 01 natural sciences, Isotopes of strontium, chemistry.chemical_compound, Isotope fractionation, chemistry, 13. Climate action, Geochemistry and Petrology, Environmental chemistry, 14. Life underwater, Gephyrocapsa oceanica, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Emiliania huxleyi
Abstract

The controls on stable Sr isotope fractionation into the calcite produced by the coccolithophore species Emiliania huxleyi , Coccolithus pelagicus spp. braarudii and Gephyrocapsa oceanica are investigated . Each species has been cultured under controlled laboratory conditions at a range of temperatures (10–25 °C) to test the potential of δ 88/86 Sr as a proxy for growth rate and/or sea surface temperature. Coccolithophores are one of the most abundant pelagic calcifiers; since Sr substitutes to some degree for Ca in their calcite coccoliths, coccolithophores represent a significant output of Sr from seawater, potentially influencing the δ 88/86 Sr mass balance in the modern oceans. The coccoliths are investigated for their δ 88/86 Sr, Sr/Ca, and δ 18 O measured as function of temperature. As temperature is increased all species show a negative stable Sr isotopic fractionation, related to a temperature controlled growth rate. We infer the shift of δ 88/86 Sr to lighter values as indicative of a kinetic control on the isotope fractionation, revealing the potential of δ 88/86 Sr as a proxy for growth rate, which in these experiments is primarily dictated by temperature. The results from these experiments indicate that coccolithophore calcite incorporates Sr with a very light δ 88/86 Sr isotope composition as low as ∼0‰.

Published
2014

29. The behaviour of magnesium and its isotopes during glacial weathering in an ancient shield terrain in West Greenland

Author

Josh Wimpenny, Fatima Mokadem, Abdelmouhcine Gannoun, Rachael H. James, Kevin W. Burton, Sigurður R. Gislason, Department of Earth and Environmental Sciences [Milton Keynes], The Open University [Milton Keynes] (OU), Department of Earth Sciences [Oxford], University of Oxford [Oxford], National Oceanography Centre [Southampton] (NOC), University of Southampton, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institute of Earth Sciences [University of Iceland], University of Iceland [Reykjavik], and University of Oxford

Subjects
Hydrology, 010504 meteorology & atmospheric sciences, Carbonate minerals, Sediment, Weathering, 010502 geochemistry & geophysics, 01 natural sciences, Geophysics, Isotope fractionation, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], Silicate minerals, Environmental chemistry, [SDE]Environmental Sciences, Earth and Planetary Sciences (miscellaneous), [CHIM]Chemical Sciences, Glacial period, Dissolved load, Isotopes of magnesium, geographic locations, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

The magnesium (Mg) isotope composition of rivers is sensitive to changes in the balance of primary mineral dissolution and secondary mineral formation. As these processes are regulated by climate then changes to the Earth's climate system, such as the onset of glaciation, could potentially alter the isotopic behaviour of Mg in rivers. To investigate how Mg isotopes behave during glacial weathering, we have determined the Mg concentration and Mg isotope ratio for the dissolved, suspended and bedload phases of glacial and non-glacial rivers in west Greenland. This region is essentially monolithological and there is little biological activity; hence isotope variations largely result from differences in weathering processes. Dissolved Mg in rivers is always enriched in the light Mg isotopes relative to the bedload (δ26Mg=-0.4%),and the glacial rivers have lighter Mg isotope compositions (δ26Mg -1 to -1.3%) than the non-glacial rivers (δ26Mg ~ -0.6%). Enrichment of light Mg in the dissolved load is consistent with the preferential uptake of heavy Mg from solution during the formation of secondary silicate minerals. However, evidence from saturation state modelling suggests that little secondary mineral formation is likely to have occurred in the glacial rivers because the concentration of dissolved solids is very low. Moreover, the glacial derived suspended sediment has identical Mg isotope ratios to the bedload. These observations suggest that the formation of secondary weathering minerals is not controlling the behaviour of Mg isotopes in these rivers. Rather, variations in the δ26Mg value of the dissolved load are attributed to incongruent weathering of the solid phase: preferential dissolution of carbonate minerals, which have low δ26Mg (-1.1 to -5.2%), imparts a more negative δ26Mg signal to the glacial river waters. Although our study indicates that the Mg isotopic composition of the dissolved load is sensitive to changes in weathering congruence, it is unlikely that glaciation will result in major changes in the δ26Mg composition of continental runoff. © 2011 Elsevier B.V.

Published
2011

30. Glacial effects on weathering processes: New insights from the elemental and lithium isotopic composition of West Greenland rivers

Author

Abdelmouhcine Gannoun, Fatima Mokadem, Josh Wimpenny, Sigurður R. Gislason, Kevin W. Burton, Rachael H. James, Department of Earth and Environmental Sciences [Milton Keynes], The Open University [Milton Keynes] (OU), National Oceanography Centre [Southampton] (NOC), University of Southampton, Department of Earth Sciences [Oxford], University of Oxford [Oxford], Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institute of Earth Sciences [University of Iceland], University of Iceland [Reykjavik], and University of Oxford

Subjects
010504 meteorology & atmospheric sciences, Geochemistry, Weathering, engineering.material, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Deglaciation, [CHIM]Chemical Sciences, Glacial period, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Total suspended solids, Total dissolved solids, Geophysics, Oceanography, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, engineering, Clay minerals, Geology, Biotite, Gneiss
Abstract

Greenland is by far the dominant source of glacial runoff to the oceans but the controls on the chemical and isotopic composition of this runoff are poorly known. To better constrain glacial effects on weathering processes, we have conducted elemental and lithium isotope analyses of glacial and non-glacial rivers in gneiss catchments in West Greenland. The glacial rivers have high total suspended solids (0.5 g l? 1) and low total dissolved solids (12 ?Scm? 1) relative to the non-glacial rivers, and they contain a higher proportion of dissolved Ca2+ and K+ because of subglacial, preferential, weathering of trace carbonates and biotite. The glacial rivers also have high SO42? because of the oxidation of trace sulphides under the ice. Both glacial and non-glacial rivers have high ?7Li (respectively, not, vert, similar 26‰ and not, vert, similar 30‰) relative to the rocks from which the Li is derived (not, vert, similar 8‰). Saturation state modelling suggests that this is due to the formation of Fe-oxyhydroxides in the non-glacial rivers, with preferential uptake of 6Li during inner sphere sorption of Li+ on the Fe-oxyhydroxide surface. Glacial rivers, however, are undersaturated with respect to clay minerals and Fe-oxyhydroxides. Nevertheless, leaching of suspended sediments indicates that not, vert, similar 65% of the Li in these sediments is associated with Fe-oxyhydroxide phases, and the ?7Li value of this Li is low, not, vert, similar 5‰. These results suggest that these Fe-oxyhydroxides formed under the ice, as a product of sulphide oxidation, with preferential uptake of 6Li onto the mineral surface. Solubilisation of Li from these Fe-oxyhydroxide phases is unlikely to represent a significant flux of Li to the oceans. Moreover, because the difference between the ?7Li values of glacial vs non-glacial rivers is small, glaciation has not had a significant impact on the Li isotopic composition of the riverine flux delivered to the oceans in the past, even at the height of the last deglaciation.

Published
2010

31. The relationship between riverine lithium isotope composition and silicate weathering rates in Iceland

Author

Romain Millot, Kevin W. Burton, Sigurdur R. Gislason, Fatima Mokadem, Nicolas Vigier, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Iceland [Reykjavik], Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), and Sorbonne Université (SU)

Subjects
basalt, 010504 meteorology & atmospheric sciences, Geochemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Weathering, Li isotopes, 010502 geochemistry & geophysics, 01 natural sciences, chemistry.chemical_compound, Isotope fractionation, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Basalt, Continental crust, Sediment, erosion, Silicate, rivers, Geophysics, silicate weathering, chemistry, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Erosion, Sedimentary rock, Geology
Abstract

This study presents lithium isotope and elemental data for the dissolved phase and suspended and bedload sediments of the major Icelandic rivers. For the dissolved phase, δ7Li values range between 10.1‰ and 23.8‰, while river sediments display lower and much more homogeneous values (δ7Li = 3.1‰-4.8‰), close to the composition of unweathered Mid-Ocean Ridge Basalt (MORB). High δ7Li values are associated with high K/Li, Na/Li and Mg/Li ratios, in waters draining mainly old and weathered basalt catchments, whereas low δ7Li rivers are located in younger parts of the island. Simple mixing between precipitation, Li-rich hydrothermal springs and basalt weathering is unable to explain the entire range of δ7Li values. Instead, a simple model of Li uptake by secondary minerals, associated with clay-water Li isotope fractionation (Δ7Li ranging from - 1‰ to - 7.5‰) can explain both water and sediment δ7Li values. A negative correlation is observed between basalt chemical erosion rates and δ7Li measured in Icelandic rivers, and an empirical law is inferred. Comparison with literature data suggests that this relationship may be applicable at a more global scale, and, if confirmed, could be of particular use for estimating the evolution of continental weathering preserved in marine sedimentary records. However, more data are now needed for rivers draining silicates typical of the continental crust, in order to refine large scale modelling. © 2009 Elsevier B.V. All rights reserved.

Published
2009

32. Riverine behaviour of uranium and lithium isotopes in an actively glaciated basaltic terrain

Author

Sigurður R. Gislason, Rachael H. James, Kevin W. Burton, Philip A.E. Pogge von Strandmann, Fatima Mokadem, Peter van Calsteren, Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU), Institute of Earth Sciences [University of Iceland], University of Iceland [Reykjavik], Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Geochemistry, chemistry.chemical_element, Weathering, 010502 geochemistry & geophysics, 01 natural sciences, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Bed load, Isotopes of uranium, Trace element, 15. Life on land, Uranium, Geophysics, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, Erosion, population characteristics, Suspended load, Dissolved load, Geology, geographic locations
Abstract

This study presents U and Li isotope and major and trace element data for the dissolved load, suspended particulates and bedload for Icelandic rivers draining predominantly basaltic catchments. Physical erosion rates range from 920 to 2084 t/km2/yr, with the higher values associated with glacier-fed rivers. Chemical erosion rates range from 45 to 91 t/km2/yr, with lower rates being associated with glacier-fed rivers. Uranium activity ratios, (234U/238U), are close to secular equilibrium in the suspended and bedloads, but all dissolved load samples show values greater than unity, ranging from 1.13 to 2.41. The highest (234U/238U) values are found in glacier-fed rivers, and can be attributed to α-recoil effects, as grinding by glaciers locally enhances rates of physical weathering. Activity ratios in glacial rivers decrease with distance from the glacial source due to input from non-glacial tributaries which have high levels of dissolved uranium and lower activity ratios. In contrast, in non-glacial rivers, uranium activity ratios increase with distance downstream due to continued weathering in soils and of bedrock. The δ7Li value of the suspended load is always lower than that of the bedload due to preferential retention of 6Li in secondary minerals during weathering. In turn, the δ7Li value of the dissolved load is always greater than that of the bedload, ranging from 17.0 to 43.7‰. δ7Li for the dissolved load decreases with increasing levels of dissolved silicon, and the saturation index of secondary minerals, which suggests that δ7Li decreases with increasing chemical weathering. There is no correlation between δ7Li values and uranium activity ratios for the dissolved load for non-glacial rivers, but for glacier-fed rivers there is an increase in δ7Li with increasing (234U/238U), suggesting that where physical comminution of mineral grains by glaciers is high, chemical weathering is suppressed, and vice-versa. © 2006 Elsevier B.V. All rights reserved.

Published
2006

33. 238U–230Th disequilibrium in recent basalts and dynamic melting beneath the Kenya rift

Author

Ray Macdonald, Fatima Mokadem, L. E. Thomas, Nick Rogers, Chris J. Hawkesworth, Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU), Lancaster Environment Centre, Lancaster University, University of Bristol [Bristol], Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Basalt, Rift, 010504 meteorology & atmospheric sciences, Trace element, Geochemistry, Geology, Fractionation, Secular equilibrium, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Mantle plume, 13. Climate action, Geochemistry and Petrology, Chondrite, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Trace element and U-series isotope analyses are presented for a suite of recent ( 10 × chondrite and the LREE between 60 and 200 × chondrite. REE fractionation is consistent with melting a garnet lherzolite source region with between 2% and 6% modal garnet. Other trace element ratios are distinct from OIB, notably Zr/Hf which ranges from 43 to 48, whilst at a given Zr content the Zr/Hf ratio is significantly greater than that found in OIB. (238U/232Th) range from 0.362 to 1.036, (230Th/232Th) from 0.503 to 1.109, with (230Th/238U) ranging from 0.783 to 2.966. All but two samples are in 230Th excess or in secular equilibrium. Samples with elevated (238U/232Th), also have Rb/Cs > 120, but unexceptional 208Pb/206Pb and hence κPb values. These samples have experienced U and Cs loss and are excluded from further consideration. Of the unaltered samples, all have (238U/232Th) generally lower than OIB, with maximum values of < 0.8, and some < 0.6. The maximum (230Th/238U) is 1.39, similar to OIB. Although none of the basalts has a primary composition, (230Th/238U) does not vary systematically with indices of fractionation, and comparison with evolved rocks from Kenya indicates that 238U–230Th disequilibrium in the basalts is not the product of fractionation and crustal residence, but a product of melt generation. The maximum (230Th/238U) that can be generated by batch melting, assuming a source mineralogy consistent with the REE variation is 1.05 and so the variation in (230Th/238U) is attributed to more complex models of melt generation and/or transport. Both dynamic melting and equilibrium porous flow suggest mantle upwelling rates of ≤ 2 cm year− 1. It is suggested that the Kenya basalts represent melts derived from lithospheric mantle that has been thermally reactivated by and incorporated into the underlying (East African) mantle plume.

Published
2006

34. The influence of weathering process on riverine osmium isotopes in a basaltic terrain

Author

Abdelmouhcine Gannoun, Kevin W. Burton, Nathalie Vigier, Sigurdur R. Gíslason, Nick Rogers, Fatima Mokadem, Bergur Sigfússon, Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Geophysics, 010504 meteorology & atmospheric sciences, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, [SDU]Sciences of the Universe [physics], Earth and Planetary Sciences (miscellaneous), 15. Life on land, 010502 geochemistry & geophysics, 01 natural sciences, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

This study presents Os isotope and comprehensive major and trace element data for the dissolved load, suspended particulates and bedload for Icelandic rivers, draining predominantly basaltic catchments that range in age from historic to ca. 12 Ma. Hydrothermal waters and precipitation have also been analysed. Both Os and Re concentrations are greater in the suspended load than the bedload, while Re/Os ratios are lower, suggesting that both elements are concentrated in weathering resistant minerals. Despite this elemental fractionation the suspended particulates and bedload for each river yield indistinguishable 187Os/188Os isotope compositions that range from 0.136 to 0.292. In contrast, the dissolved load (< 0.2 μm filtered) often possesses a significantly more radiogenic Os isotope composition than the corresponding suspended or bed load with 187Os/188Os ratios ranging from 0.15 to 1.04. The isotope and elemental data for the dissolved load can be explained in terms of an unradiogenic contribution from congruent basalt weathering (and/or hydrothermal input) and a radiogenic contribution that arises from two distinct processes. For the glacier-fed rivers there is a covariation between 187Os/188Os and the extent of glacial cover in the catchment, and this is most readily explained by the entrainment of seawater aerosols into precipitation and subsequent glacial melting. While for direct-runoff (and spring-fed rivers) there is a covariation between 187Os/188Os and the age of the bedrock in the catchment, that cannot be explained by congruent weathering of old basalt. Calculations indicate that those direct-runoff rivers with radiogenic 187Os/188Os values are also undersaturated with respect to the primary basalt minerals olivine, pyroxene and plagioclase, indicating that these phases are unstable and prone to preferential dissolution. Published Re-Os isotope data indicate that the same phases possess exceptionally high 187Re/ 188Os ratios and thus evolve to radiogenic 187 Os/188Os compositions in very short time intervals. Taken together, these results indicate that incongruent (preferential) weathering of certain primary basalt minerals can impart a radiogenic Os isotope composition to the dissolved riverine load. Nevertheless, overall the Os isotope signal to the Oceans from Icelandic rivers is little affected because rivers with unradiogenic 187Os/ 188Os values and a high discharge dominate the Os flux. © 2006 Elsevier B.V. All rights reserved.

Published
2006

35. Growth rates of the deep-sea scleractinia Desmophyllum cristagalli and Enallopsammia rostrata

Author

Jess F. Adkins, Steve O'Shea, S.-L. Wang, Fatima Mokadem, Gideon M. Henderson, Caltech Department of Astronomy [Pasadena], California Institute of Technology (CALTECH), Department of Earth Sciences [Oxford], University of Oxford [Oxford], National Institute of Water and Atmospheric Research [Wellington] (NIWA), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, Range (biology), Coral, Climate change, Scleractinia, 01 natural sciences, Deep sea, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), [CHIM]Chemical Sciences, 14. Life underwater, Growth rate, Transect, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Radionuclide, biology, 010604 marine biology & hydrobiology, biology.organism_classification, Geophysics, Oceanography, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [SDE]Environmental Sciences, Geology
Abstract

With uranium rich skeletons and density bands similar to their surface coral counterparts, deep-sea scleractinia are a promising archive of past climate. To improve the utility of fossil samples as monitors of deep ocean variability, we have measured 210 Pb and 226 Ra activities in a variety of modern specimens to constrain the range of growth rates. Mechanical and chemical cleaning of each sample are required to isolate the radionuclides trapped in the coral skeleton from surface contaminants. However, in many cases mechanically cleaned samples show the same overall growth rate as parallel transects of samples subjected to the full chemical and mechanical cleaning but with much higher overall activities. Three samples of Desmophyllum cristagalli show a range of vertical extension rates from 0.5 mm/yr to 2 mm/yr, consistent with previous estimates. A single Enallopsammia rostrata from the North Atlantic is over 100 years old. Its average radial growth rate is 0.07 mm/yr, and the clear banding in this direction is not consistent with annual periodicity. A minimum vertical extension rate of 5 mm/yr is estimated from the 210 Pb data. Both of these species are found in the fossil record and, with the growth rates determined here, can record about 100 years of climate change. The growth rates will allow the reconstruction of climate at subdecadal resolution in D. cristagalli and even higher resolution in E. rostrata. D 2004 Elsevier B.V. All rights reserved.

Published
2004

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