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Your search keyword '"Youssef Nohra"' showing total 2 results
Start Over Author "Youssef Nohra" Topic 01 natural sciences
2 results on '"Youssef Nohra"'

1. New Jurassic amber outcrops from Lebanon

Author

Antoine El-Samrani, Youssef Nohra, Dany Azar, Vincent Perrichot, Sibelle Maksoud, Raymond Gèze, 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), Department of Natural Sciences, Lebanese University [Beirut] (LU), 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 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)-Centre National de la Recherche Scientifique (CNRS), and Lebanese University [Beirut]

Subjects
infrared spectrum, 010506 paleontology, Paleontology, FTIR, Outcrop, Late Jurassic, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Lebanon, 010502 geochemistry & geophysics, 01 natural sciences, Cretaceous, 0105 earth and related environmental sciences
Abstract

International audience; Amber predating the Lower Cretaceous is extremely rare. During the past two decades, records of discoveries of amber sites have increased considerably worldwide. We report herein the discovery of ten new outcrops of amber from the Late Jurassic in Lebanon, in addition to other nine outcrops described by Azar et al. (2010). Some of these outcrops gave large centimetric sized amber pieces. Each of these new amber outcrops is described, and its infrared spectrum is given. Though the Jurassic amber yielded to date no more than some fungal inclusions, this discovery is significant and promising especially in the reconstruction of the paleoenvironment.

Published
2013
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2. Chemical Characterization and Botanical Origin of French Ambers

Author

Youssef Nohra, Dany Azar, Vincent Perrichot, Laurent Le Pollès, Laurent Jeanneau, 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), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Lebanese University [Beirut] (LU), Université Libanaise, 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 de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Molecular composition, Cupressaceae, Spectrophotometry, Infrared, Tetrahydronaphthalenes, Plant composition, Pharmaceutical Science, Araucariaceae, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, GEOF, Gas Chromatography-Mass Spectrometry, Analytical Chemistry, Paleontology, Drug Discovery, Botany, Dicarboxylic Acids, 0105 earth and related environmental sciences, Pharmacology, biology, Molecular Structure, Terpenes, Organic Chemistry, Fabaceae, Plants, biology.organism_classification, Cretaceous, Amber, Cheirolepidiaceae, Tracheophyta, Complementary and alternative medicine, Molecular Medicine, France, Cenomanian, Diterpenes, Geology
Abstract

International audience; The molecular composition of 10 Cretaceous andone Eocene ambers from France was analyzed by infraredspectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy,and thermochemolysis gas chromatography−massspectrometry. The terpenoids identified in the samples wereused as biomarkers for the botanical origin of the resins. TheCretaceous samples, comprising the so-called Alpine, Anjou,Charentese, Provence, Pyrenean, and Vendean ambers, rangedfrom the Albian−Cenomanian transition to the early Santonian(100 to 85 Ma) and correspond to class Ib resins typical ofconifers. The extinct conifer family Cheirolepidiaceae wasproposed as the plant source of Pyrenean and brown Charenteseambers. Araucariaceae or Cheirolepidiaceae were the plant sourcesof the Cenomanian Alpine, Anjou, and yellow Charentese ambers.The Santonian ambers of Provence and Vendée were found to derive from the Cupressaceae. The Eocene Oise amber (ca. 53Ma) is a class Ic resin typical of angiosperms and was produced by a Fabaceae. The evolution of resin sources from the earlyCretaceous to the Eocene periods is discussed. Finally, a possible fingerprint hitherto unveiled is proposed for cheirolepidiaceousresins, defined by the simultaneous presence of phenolic diterpenoids, labdanoic acids, callitrisate structures, and their respectivederivatives.

Published
2015
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