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Amazonian Dark Earths (ADEs) are unusually fertile soils characterised by elevated concentrations of microscopic charcoal particles, which confer their distinctive colouration. Frequent occurrences of pre-Columbian artefacts at ADE sites led to their ubiquitous classification as Anthrosols (soils of anthropic origin). However, it remains unclear how indigenous peoples created areas of high fertility in one of the most nutrient-impoverished environments on Earth. Here, we report new data from a well-studied ADE site in the Brazilian Amazon, which compel us to reconsider its anthropic origin. The amounts of phosphorus and calcium—two of the least abundant macronutrients in the region—are orders of magnitude higher in ADE profiles than in the surrounding soil. The elevated levels of phosphorus and calcium, which are often interpreted as evidence of human activity at other sites, correlate spatially with trace elements that indicate exogenous mineral sources rather than in situ deposition. Stable isotope ratios of neodymium, strontium, and radiocarbon activity of microcharcoal particles also indicate exogenous inputs from alluvial deposition of carbon and mineral elements to ADE profiles, beginning several thousands of years before the earliest evidence of soil management for plant cultivation in the region. Our data suggest that indigenous peoples harnessed natural processes of landscape formation, which led to the unique properties of ADEs, but were not responsible for their genesis. If corroborated elsewhere, this hypothesis would transform our understanding of human influence in Amazonia, opening new frontiers for the sustainable use of tropical landscapes going forward., Amazonian Dark Earth is soil that has had mysteriously high fertility since ancient times, despite the fact that surrounding soils have very low nutrients. Here the authors’ use of isotope reconstructions indicate that these soils predate human settlement and could have alluvial and burning origins.

The analysis of minor/microelements in anthropogenic soils resulting from past settlement activities in different environmental conditions and geographical regions is not well-known. The study aimed to determine whether minor/microelements are suitable proxy indicators of past human activities of Archaeological Dark Earth (ADE) soils from two past hilltop settlements- Ziavi-Galenkuito in Ghana and Dřevic hillfort, Czech Republic. Total and plant-available (Mehlich 3) contents of minor/microelements were determined using portable X-Ray Fluorescence spectrometry and Inductively coupled plasma mass spectrometry, respectively. The black color of the soils from Ziavi-Galenkuito and Dřevic hillfort contrasted the brownish Ferric Acrisol and greyish Luvic Cambisol control, respectively. The contents of total and plant-available Cu, Zn, Mn, Sr, and total Rb was substantially higher in both sites compared to their control of the same geological substrates. The highest total and plant-available Mn content in Ziavi-Galenkuito may indicate specific intensive settlement activities in a comparatively shorter duration. The highest total Cu, Zn, Sr, and Rb content in the soil from Dřevic hillfort compared to Ziavi-Galenkuito related to longevity and intensity of the past human activities. Total Cu, Zn, Mn, and Sr can well reflect past human activities from different geographical regions according to their significant correlations from both studied sites. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. In the calculation of enrichment factors in ADE soils for geoarchaeological purposes, total Mn, Cu, Zn, and Sr are more suitable. Enrichment by minor/microelements can be reliable enough in predicting past human activities in ADE soils of different geology and climatic conditions, even after hundreds of years.

International audience; Catastrophic events (climatic, tectonic, volcanic, etc.) frequently cause geomorphological instability, which interrupts normal pedogenesis and switches the processes of surface erosion and/or sedimentation. These processes have an effect on the distribution of ancient settlements and can be the cause of the abandonment of cities. In the Lerma Valley, particularly in the Tres Mezquites area, surveys and extensive excavations have been conducted to estimate the nature and density of pre-Hispanic settlements on the alluvial plain and in the piedmonts. Most of the archaeological structures are covered by dark clayey soils (Vertisols). This includes the PA3_El Pitayo site, where an accumulation of black earth has been detected on the floors and walls of a collapsed building. We have studied in detail the Vertisols and the black earth around the site to establish to what extent this dark earth is an in situ product of the soil-forming factors, or if its accumulation is due to erosion/sedimentation processes, which could affect the occupation of the site, or the result of anthropic activity for leveling. The Vertisols and the dark earth are characterized by different means (physical, chemical, micromorphology, clay mineralogy, and radiocarbon dating). The results show that both the Vertisols and the black earth are very clayey, with angular blocky structures and slickensides (properties that are typical of vertic soils), and smectite as the main clay mineral. Besides smectite, under the microscope, a high amount of fresh volcanic glass is identified, suggesting that volcanism could be responsible for the abandonment of the study site. However, there are no known volcanic events related to the age of abandonment. As a consequence, we consider that landslides triggered by seismic activity/climatic events impacted the settlement.

The long term response of ancient societies to climate change has been a matter of global debate. Until recently, the lack of integrative studies between archaeological, palaeoecological, and palaeoclimatological data had prevented an evaluation of the relationship between climate change, distinct subsistence strategies, and cultural transformations across the largest rainforest of the world, Amazonia. Here, we review the most relevant cultural changes seen in the archaeological record of six different regions within Greater Amazonia during late pre-Columbian times. We compare the chronology of those cultural transitions with high-resolution regional palaeoclimate proxies, showing that, while some societies faced major reorganisation during periods of climate change, others were unaffected and even flourished. We propose that societies with intensive, specialised land-use systems were vulnerable to transient climate change. In contrast, land-use systems that relied primarily on polyculture agroforestry, resulting in the formation of enriched forests and fertile Amazonian Dark Earths in the long term, were more resilient to climate change.

Cultural layers are deposits resulting from settlement and human activity on natural soil in the past. Materials from past domestic activities that become buried into the soil can be used to reconstruct human impact in a specific area in the past. For instance, humans have used fire for millennia, and charcoal in soils and sediments is applied as evidence of anthropic activity. In this context, assessing the abundance and degradation level of charcoal fragments can clarify anthropic activities in cultural deposits. In European towns, cultural layers with similar characteristics, have been defined as urban “Dark Earth” (UDE) but their age, formation and composition often differ significantly across sites. This study examined three archaeological sites in Verona, Italy, where UDE layers with similar characteristics have been identified. The primary aim of this research is to understand the anthropogenic influence on the development of UDE layers, by characterizing their geochemistry and the carbonaceous materials. To pursue this goal, we provide a micromorphological description of the sites, evaluate UDE features and the abundance of charred material and characterize the amorphous/crystalline degree through μ-Raman spectroscopy. Bulk ma- terial was described in terms of amounts of total organic carbon (TOC), recalcitrant organic carbon (ROC), total inorganic carbon (TIC), and trace element concentration. Radiocarbon dating of charred and humin fractions was performed to clarify the dynamics underlying UDE origin. We investigate the relationship between the different variables analyzed in the UDE layers at each site. Results show that a diverse array of human activities including metal tool and/or ceramic manufacturing were related to the formation of UDE layers. The investigation of carbonaceous fractions highlight differences in soil organic carbon and charred material, both of which are correlated with human influence.

Among the buried urban Anthrosols and Technosols, urban Dark Earth composes a major challenge to urban archaeologists and soil scientists. These homogeneous units are often the result of a complex formation history, involving human actions and natural processes. In order to understand the significance of the late medieval to pre-industrial urban Dark Earth observed on the site of Mundaneum in the historical centre of Mons (Belgium) an integrated soil micromorphological and phytolith study has been performed. The aim of this study is to understand how the urban Dark Earth formed and to identify the major natural and human processes that are involved in its formation. The results show that major natural processes are bio- turbation, sedimentation, humification, alkalinisation and clay translocation. These processes are mainly human induced. Main human activities include cereal cultivation, horticulture, dumping of waste and trampling. Phy- toliths proved to be an important witness of the presence of plant material, in a context where organic remains tend to decompose rapidly. The integrated approach allowed to come to a better understanding of the tapho- nomical history of the phytoliths, hence permitting to distinguish plant remains related to manure, cereal pro- cessing and in situ cultivated plants. The study further permitted the authors to gain insight in part of the biography of the site and its surroundings, hence showing changes in spatial organisation and the progressive urbanisation of the area. As such, this analysis provides an important stepstone to the further geoarchaeological study of town development in Medieval and Modern periods.

The conversion of tropical forest for cassava cultivation is widely known to decrease the soil organic matter (OM) and nutrient contents of highly weathered soils in the tropics. Amazonian Dark Earth (ADE) might be more resistant to this process due to their historical anthropogenic amelioration with e.g. charcoal, ceramics and bones, leading to higher soil OM and nutrient concentrations. In this study, we analyzed the effect of land use change on the OM dynamics under tropical conditions and how this is related with P distribution at the microscale, using ADE and an adjacent Acrisol (ACR) as model systems. Soil samples were obtained south of Manaus (Brazil), from a secondary forest and an adjacently located 40-year-old cassava plantation. The land use change induced a severe decrease of organic carbon (OC) concentrations in ADE (from 35 to 15 g OC kg‑1) while OC in the adjacent ACR was less affected (18 to 16 g OC kg‑1). The analysis by 13C NMR spectroscopy showed that the conversion of secondary forest to cassava changed the chemical composition of OM to a more decomposed state (increase of alkyl:O/N-alkyl ratio) in the ADE whereas the OM in ACR changed to a less decomposed state (decrease of alkyl:O/N-alkyl ratio). According to neutral sugar and lipid extraction analyses, land use change led to a larger impact on the microbial-derived and plant-derived compounds in the ADE compared to the ACR. In order to analyze the interactions of OC and P at the microscale, we conducted an incubation experiment with 13C glucose for the analysis with Scanning X-ray Microscopy (SXM) and Nano scale Secondary Ion Mass Spectrometry (NanoSIMS). In both soil types ADE and ACR, land use change caused a reduction of the total 13C glucose respiration by approximately one third in a 7-days incubation, implying lower microbial activity. Microorganisms in both soil types appear to be more readily active in soils under forest, since we observed a distinct lag time between 13C glucose addition and respiration under cassava planation. This indicated differences in microbial community structure, which we will be assessed further by determining the 13C label uptake by the microbial biomass and the microbial community structure using 13C PLFA analysis. Preliminary results from synchrotron-based STXM demonstrate a distinct arrangement of OM at fine-sized charcoal-particle interfaces. From ongoing NanoSIMS analyses, we expect further insights on the co-localization of P and 13C-labelled spots at the microscale. Despite the high loss of OC in the ameliorated ADE through land use change, the remaining OM might foster nutrient dynamics at the microscale thanks to charcoal interactions compared to the ACR. Our results contribute to a better understanding of the C and P interactions and how these respond to land use change in highly weathered tropical soils.

Nitrogen-based fertilizers produce crops which sustains half of the global population. While they are intrinsic for human life, excess nitrogen from fertilizer use has a negative impact on air, soil, and water quality. Furthermore, these fertilizers can gradually degrade the fertility of soils, and the production of nitrogen-based fertilizer consumes and emits large quantities of fossil fuels. Fertilizer use cannot be removed but could potentially be replaced. This thesis focuses on African Dark Earths in Ghana and discusses the feasibility of using these soils as an alternative for nitrogen-based fertilizer. This question has been examined through an overview of available literature and data regarding known anthropogenic soils in both the Amazonian Basin and West Africa. Given research into West African Dark Earths is a burgeoning field, information from Amazonian Darks Earths have been used to fill any potential knowledge gaps, considering that the two soils are considered analogous. Between research completed on these two forms of anthropogenic soil, Dark Earths are discussed in terms of how they are made, why they are made, what chemical properties they contain, and what impact they have on soil fertility and agricultural yield. Ghana is taken as a case study to contextualise these soils and examine how they are made and used in a contemporary setting. This thesis then discusses whether the impact these Dark Earths have on the local communities within which they are created could be extrapolated to industrial-scale farming. Given the time, cultural and spatial constraints of Ghanaian African Dark Earth production, it was determined they cannot be feasibly scaled-up to be of any significant impact on contemporary industrial farming. However, for local communities, this method of soil production may have positive and long-lasting benefits. This thesis concludes by discussing other substitutes to nitrogen-based fertilizers, resolving that while research and development into these technologies is in its nascent phase, there is reason to be optimistic about the future of food production.

Archaeological Dark Earth (ADE) is a layer of anthrosol (syn. anthroposol) visually characterized by dark color mainly due to homogenous charcoal inclusion, and substantial enrichment by nutrients in comparison to surrounding soils. ADE is distributed from the tropics (Amazonian Terra preta, African ADE), moderate climatic zones (European ADE) up to the Arctic (kitchen middens). Although ADE soils have been studied also in other regions of the world, they have no special regional names. All types of ADE developed as a result of deliberate and/or unintentional deposition of domestic/occupational wastes, charred residues, bones, shells, and biomass ashes from prehistoric up to recent times. ADEs have optimum C : N ratio for effective mineralization, stable organic matter content, reduced acidity, higher CEC and C, N, P, Ca, Mn, Cu, Zn, Mn, Mg, Fe, Sr, and Ba content in comparison to surrounding soils. The unclear remains the level of ADEs enrichment by these elements as enrichment factors for different elements are based on different analytical approaches from plants-available up to total contents in the soil. Although generally highly productive, comparison of herbage production and crop yields between ADEs and natural soils are still rare. The distribution and persistence of anthropogenic activities leading to the formation of ADEs indicate that they are subject to the continual formation.

The Dark Target aerosol algorithm was developed to exploit the information content available from the observations of Moderate-Resolution Imaging Spectroradiometers (MODIS), to better characterize the global aerosol system. The algorithm is based on measurements of the light scattered by aerosols toward a space-borne sensor against the backdrop of relatively dark Earth scenes, thus giving rise to the name “Dark Target”. Development required nearly a decade of research that included application of MODIS airborne simulators to provide test beds for proto-algorithms and analysis of existing data to form realistic assumptions to constrain surface reflectance and aerosol optical properties. This research in itself played a significant role in expanding our understanding of aerosol properties, even before Terra MODIS launch. Contributing to that understanding were the observations and retrievals of the growing Aerosol Robotic Network (AERONET) of sun-sky radiometers, which has walked hand-in-hand with MODIS and the development of other aerosol algorithms, providing validation of the satellite-retrieved products after launch. The MODIS Dark Target products prompted advances in Earth science and applications across subdisciplines such as climate, transport of aerosols, air quality, and data assimilation systems. Then, as the Terra and Aqua MODIS sensors aged, the challenge was to monitor the effects of calibration drifts on the aerosol products and to differentiate physical trends in the aerosol system from artefacts introduced by instrument characterization. Our intention is to continue to adapt and apply the well-vetted Dark Target algorithms to new instruments, including both polar-orbiting and geosynchronous sensors. The goal is to produce an uninterrupted time series of an aerosol climate data record that begins at the dawn of the 21st century and continues indefinitely into the future.

Studying particle size distribution is important to understand soil structure and formation processes. This research aimed to assess the fractal dimension of soil texture in Indian Dark Earth (IDE) areas in southern Amazonas state under different land uses, as follows: two areas in the municipality of Apuí, one growing cocoa and the other coffee; a grassland area in the municipality of Manicoré; and a forest area in the municipality of Novo Aripuanã. A sampling grid containing 88 collection points (intersecting points on the grid) was established in each area, measuring 80 x 42 m for the cocoa and coffee-growing sites, and 80 x 56 m and 60 x 42 m for the grassland and forest areas, respectively. Soil samples were collected in soil core and as clumps at a depth of 0.0-0.20m to determine the structural physical properties and texture of the soil. The following physical attributes were assessed: texture (PSD), bulk density (BD), macroporosity (Macro), microporosity (Micro), total porosity (TP) and aggregate stability (GMD and WMD). The fractal dimension (D) of the soil texture was determined, followed by analysis of variance and comparison of the means using Tukey’s test (p≤0.05). Pearson’s correlation was applied to assess the correlation between variables. There was a significant difference between the IDEs studied, with a higher D value in the cocoa-growing area in relation to the other sites. Additionally, the larger the clay fraction, the higher the D value. Fractal dimension (D) showed a positive correlation with sand, clay, BD, Macro, GMD and WMD, and a negative correlation with silt, micro, TP. Based on the D values obtained, the ADE cultivated with cocoa showed superior quality in relation to the other areas studied. Estudar a distribuição do tamanho das partículas é importante para entender a estrutura do solo e os processos de formação. Esta pesquisa teve como objetivo avaliar a dimensão fractal da textura do solo em áreas de Terra Preta de Índio (TPI) no sul do Estado do Amazonas sob diferentes usos da terra: duas áreas no município de Apuí, uma com cultivo de cacau e outra de café; uma área de pastagem no município de Manicoré; e uma área florestal no município de Novo Aripuanã. Uma malha de amostragem contendo 88 pontos de coleta (pontos de interseção na grade) foi estabelecida em cada área, medindo 80 x 42 m para as áreas de cacau e café, e 80 x 56 m e 60 x 42 m para as áreas de pastagem e floresta, respectivamente. Amostras de solo foram coletadas em torrões a uma profundidade de 0,0-0,20 m para determinar as propriedades físicas estruturais e a textura do solo. Os seguintes atributos físicos foram avaliados: textura, densidade do solo (DS), macroporosidade (Macro), microporosidade (Micro), porosidade total (PT) e estabilidade de agregados (DMG e DMP). Determinou-se a dimensão fractal da textura do solo (D), seguida da análise de variância e comparação das médias pelo teste de Tukey (p≤0,05). A correlação de Pearson foi aplicada para avaliar a correlação entre as variáveis. Houve uma diferença significativa entre as TPIs estudadas, com um maior valor D na área de cultivo de cacau em relação aos outros locais. Além disso, quanto maior a fração argila, maior o valor de D. A dimensão fractal (D) apresentou correlação positiva com areia, argila, DS, Macro, DMG e DMP, e correlação negativa com silte, micro, PT. Com base nos valores de D obtidos, as TPIs cultivadas com cacau apresentaram qualidade superior em relação às demais áreas estudadas.

During archaeological excavations of a medieval stronghold in Rozprza, a buried thick deposit of deep black (Dark Earth type) soil was discovered. A multianalytical (sedimentological, geochemical and archaeobotanical) study was carried out in order to identify traits the Rozprza Dark Earth. The analyses demonstrated that the soil was formed as an effect of surface accumulation of organic deposits from swampy areas and waste materials with rich admixtures of organic materials. The organic carbon content of the soil of the Rozprza Dark Earth was twice as high, and the total concentration of P was many times higher as compared with the adjacent soil outside the stronghold. Plant macroremains which were recorded within the buried soil and a cultural layer are evidence for human activity, mainly wood gathering and agriculture. In the Early Middle Ages, summer crops could be cultivated there with the use of tilling methods characteristic for root crops or gardens. The accumulation of the Rozprza Dark Earth commenced in the second half of the tenth century AD. In the period between the eleventh and thirteenth century, a ring-fort was established there. The deep black soil is partly covered by the ring-fort’s rampart. The rampart was built with the use of re-deposited earlier cultural layers and sand of the subsoil. It was then clad with sod bricks. Such a construction of a medieval rampart has been recorded for the first time in the territory of Poland. A new interpretation of archaeological structures and cultural layers offers a basis for new conclusions concerning the chronology and the development stages of the medieval settlement and ring-fort in Rozprza.

Fundação de Apoio a Pesquisa e à Inovação Tecnológica do Estado de Sergipe - FAPITEC/SE Current research in Archeology and related areas in the Amazon has highlighted the role of dark earth sites as indicators of a social transformation that took place in the middle Holocene: the emergence of demographically dense occupations and the intensity of these occupations over long periods in the archaeological record, as well as their relationship with agriculture and / or the domestication of plants. However, little research has been carried out on the lithic material of these sites. In this way we propose to work on the archeological site Garbin (RO), which presents the dark earth with the oldest recorded date, 7740 AP, thus marking the beginning of this social transformation among the Amazonian populations. This research took place from the analysis of the transformation of the lithic traces observed on the site, which allowed us to identify the lithic raw materials, the methods and techniques used to work it, their distribution and concentration in space and time within the site. Based on this, it was possible to infer that the marker, among the lithic industries, of this behavioral change is in the replacement of the use of lithic material in activities of cutting, scraping, drilling, etc., by activities related to the extraction of mineral pigment from rocks lateritic and the possible manufacture of adornments in mafic igneous rocks. Atuais pesquisas em Arqueologia e áreas afins na Amazônia tem destacado o papel dos sítios de terra preta como indicadores de uma transformação social ocorrida no Holoceno médio: o surgimento das ocupações demograficamente densas e a intensidade dessas ocupações durante longos períodos no registro arqueológico, assim como sua relação com a agricultura e/ ou a domesticação de plantas. Entretanto, poucas pesquisas sobre o material lítico desses sítios foram realizadas. Desta forma nos propomos a trabalhar o sítio arqueológico Garbin (RO), que apresenta a terra preta com datação mais antiga registrada, 7740 AP, marcando assim, o início dessa transformação social dentre as populações amazônicas. Esta pesquisa se deu a partir da análise da transformação dos vestígios líticos observados no sítio, que nos permitiu identificar as matérias-primas líticas, os métodos e técnicas utilizadas para trabalhá-la, sua distribuição e concentração no espaço e tempo dentro do sítio. Com base nisso, nos foi possível inferir que o marcador, dentre as indústrias líticas, desta mudança comportamental está na substituição do uso do material lítico em atividades de cortar, raspar, furar, etc., por atividades relacionadas a extração de pigmento mineral de rochas lateríticas e a possível a fabricação de adornos em rochas ígneas máficas. Laranjeiras

The conversion of tropical forest for cassava cultivation is widely known to decrease the soil organic matter (OM) and nutrient contents of highly weathered soils in the tropics. Amazonian Dark Earth (ADE) might be affected less due to their historical anthropogenic amelioration with e.g. charcoal, ceramics and bones, leading to higher soil OM and nutrient concentrations. In this study, we analysed the effect of land use change on the OM dynamics and its composition under tropical conditions, using ADE and an adjacent Acrisol (ACR) as model systems. Soil samples were obtained south of Manaus (Brazil), from a secondary forest and an adjacently located 40-year-old cassava plantation. The land use change induced a severe decrease of organic carbon (OC) concentrations in ADE (from 35 to 15 g OC kg‑1) while OC in the adjacent ACR was less affected (18 to 16 g OC kg‑1). Soils were analysed by 13C NMR spectroscopy to obtain information on how the conversion of secondary forest to cassava affected the chemical composition of OM. Our results show that land use change induces differences in the OM composition: The OM in ADE changes to a more decomposed state (increase of alkyl:O/N-alkyl ratio) whereas the OM in ACR changes to a less decomposed state (decrease of alkyl:O/N-alkyl ratio). According to a molecular mixing model, land use change influenced mostly the proportion of lipids, which might be related with a change of the plant input. The incubation of the soils with 13C glucose enabled resolving how soil microorganisms were affected by land use change. In both soil types ADE and ACR, land use change caused a reduction of the total 13C glucose respiration by approximately one third in a 7-days incubation, implying lower microbial activity. Microorganisms in both soil types appear to be more readily active in soils under forest, since we observed a distinct lag time between 13C glucose addition and respiration under cassava planation. This indicated differences in microbial community structure, which we will assess further by determining the 13C label uptake by the microbial biomass and the microbial community structure using 13C PLFA analysis. Preliminary results from synchrotron-based STXM demonstrate a distinct arrangement of OM at fine-sized charcoal-particle interfaces. Samples of soils receiving 13C label will be further analysed by NanoSIMS with the hypothesis that charcoal interfaces foster nutrient dynamics at the microscale. Despite the high loss of OC in the ameliorated ADE through land use change, the remaining OM might improve the nutrient availability thanks to charcoal interactions compared to the ACR. Our results contribute to a better understanding of the sensitivity of OM upon land use change and how the microbial community is responding to land use change in highly weathered tropical soils.

International audience; At Gien (France), indoor floors from early Middle Ages occupation (8th–10th c. AD) are very well preserved, providing a new reference for archaeological investigation in northern France. This site is located on an outcrop, 20 m above the Loire valley, where a 15th c. castle stands now. The medieval occupation combines high-status houses with crafting and agricultural areas. They constitute a new urban nucleus, which grew 2 km east from an ancient Roman settlement. During the rescue excavation, four buildings of different status were sampled and studied using an integrated approach, combining stratigraphy, micromorphology, chemical, macro-remain and phytolith analyses. Micromorphological investigations helped to identify 74 built floors, from 0.5 to 150 mm thick, made with transformed local clay or imported silty earth. Mineral floors were covered by vegetal ones, consisting of crop processing refuse. These litters include an abundance of phytoliths and some seeds, both produced by cultivated cereals, which were processed in situ, such as Triticum durum, Secale cereale and Hordeum vulgare. The refuse above the mineral and vegetal floors were trampled. They were produced not only by domestic activities, such as cooking and eating, but also by metallurgic activities and animal husbandry. The investigation of a contemporary pit indicated that, despite the large amount of refuse, floors were well maintained and regularly rebuilt. The spatial distribution of waste indicated that a single space could be dedicated to several activities, which were not necessarily separated by new floors. Moreover, the total absence of bioturbation allowed the study of a stage of dark earth formation, by comparing it to the contemporaneous mechanical disturbance of a part of the strata which occurred when building new floors. All these results give new evidence of the richness and the complexity of the early Middle Ages town, in addition to help identifying the activities which could take place in early castral areas.

Archaeological surveys carried out between 2014 and 2017 in Barzan have showed that the roman site has survived to late Antiquity, in several forms, and long after its supposed abandon, at least until the tenth century. Use of old constructions, new ones, conversion of public spaces and monuments, those alternatives accord themselves to the preexisting buildings. Food storage areas and also funerary sectors also appeared, depicting a dense occupation made of several distinct spots., Des investigations menées entre 2014 et 2017 à Barzan ont permis d’établir que l’agglomération antique a perduré, sous des formes variées, longtemps après son abandon, supposé jusqu’alors aux IIIe-IVe s. 1, et au moins jusqu’au Xe s. Occupation d’anciennes constructions, investissement des espaces et des monuments publics, constructions nouvelles, les scénarios s’adaptent au bâti préexistant. Des zones d’ensilage et des secteurs funéraires sont également apparus, révélant une occupation apparemment assez dense. Celle-ci est composée de plusieurs noyaux distincts, qui ne sont pas tous contemporains., Gissinger Bastien. Les occupations tardo-antiques et altomédiévales à Barzan d’après les investigations récentes. In: Aquitania : une revue inter-régionale d'archéologie, tome 34, 2018. pp. 241-255.

Specific soil micromorphological, broader geoarchaeological and environmental archaeology signatures of settlement activities and land use have been identified from numerous case studies across Europe – from Romania to western Norway. In order to demonstrate how such investigations contribute to our understanding of settlement morphology and its wider landscape, an improved way of organising site-specific information or guide was created (Macphail and Goldberg, in press). Activities and land use are divided into ‘Within Settlement’, ‘Peripheral to Settlement’ and ‘The Settlement's Wider Landscape’. Major themes identified are: Constructions (and materials), Trackways and paths (and other communication/transport-associated features), Animal Management, Water Management, Waste Disposal (1: middening; 2: human waste), Specialist Domestic and Industrial Activities and Funerary Practices. In the case of trackway deposits, their characterisation aids the identification of intensely occupied areas compared to rural communications, although changing land use within urban areas has also produced ‘rural signatures’ (e.g. as associated with animal management), for example in Late Roman cities. Specialist activities such as fish and crop processing or working with lead and other metals, in-field and within-wall manuring, stabling and domestic occupation floor-use evidence, and identification of different funerary practice – cremations, boat graves and other inhumations, and excarnation features – and peripheral constructions such as boat-houses, are also noted. New information from the Chalcolithic tell site of Borduşani-Popină, Romania and seasonally occupied Viking settlement of Heimdaljordet, Norway, is introduced.

Numerous patches of black soil can be found throughout the Amazon basin, primarily along the margins of rivers. This type of soil is known as Archaeological Dark Earth (ADE) and is formed as a result of prehistoric human occupation and classified as Anthrosols. The chemical characteristics of ADE are distinct from those of the region's predominant soils, making them popular with local subsistence farmers. The patches of ADE are characterized by an abundance of ceramic fragments (sherds) (CF) both on the surface of the patches and within their inner depths. Considering that these sherds are generally composed of quartz, metakaolinite, feldspars, non-plastic materials, often with high levels of aluminum phosphates, the present study focused on their potential contribution to maintenance to the fertility of ADE soils, under the conditions of tropical weathering. With this aim, the mineralogical composition of the sherds was obtained using X-ray diffraction with the support of SEM-EDS readings. In addition, some parameters of fertility were measured as well as phosphates dissolution in the presence of citric acid as a function of time. The nutrients and micronutrients were determined by atomic absorption spectrometry and the molybdenum blue method. The results showed that the fragments analyzed were composed of quartz, feldspars, metakaolinite, micas/illites, and anatase, but differ in the presence/absence of chlorites, talc, cristobalite, and calcites. This study characterized the sherds as highly fertile and provides experimental confirmation that the sherds release phosphor under conditions approximating the natural weathering environment, which indicates that they are an important potential source of nutrients.

Made available in DSpace on 2020-12-10T20:05:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01. Added 1 bitstream(s) on 2021-07-15T15:06:56Z : No. of bitstreams: 1 S0103-50532020000801623.pdf: 2286528 bytes, checksum: 92377067520636b9654d5e429405c88c (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FUNCAP The chemical and spectroscopic characteristics of soil organic matter (SOM) isolated from Amazonian dark earth (ADE) and surrounding soil (SR) were evaluated according to the soil depth. The results showed opposite trends for the soils. While ADE featured SOM with a greater aromatic condensation degree and greater hydrophobicity in the top layer, the SR showed more aliphatic and polar SOM. The SOM arrangement from ADE was less hydrophobic, aromatic, and more polar in depth. In contrast, the SOM from SR showed an increase in molecular weight and hydrophobicity. Besides the aromatic protection in the SOM from ADE, there was organo-mineral protection through binding to soil minerals. This suggested that the SOM from ADE was protected by its hydrophobicity and interaction with minerals compared with that from the SR, thereby showing that the combination of both characteristics is important to create new technologies for soil carbon storage. Univ Estadual Paulista Julio de Mesquita Filho Un, Lab Estudos Ciencias Ambientais LECA, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil Embrapa Instrumentacao, BR-13560970 Sao Carlos, SP, Brazil Univ Fed Ceara, Lab Mat Funcionais Avancados LaMFA, Dept Fis, BR-60440554 Fortaleza, Ceara, Brazil Univ Estadual Paulista Julio de Mesquita Filho Un, Lab Estudos Ciencias Ambientais LECA, Inst Biociencias Letras & Ciencias Exatas, BR-15054000 Sao Jose Do Rio Preto, SP, Brazil FAPESP: 15/22954-1 FAPESP: 2018/15733-7 FAPESP: 2017/15733-7 FAPESP: 2017/05575-2 FUNCAP: PRONEX PR2-0101-00006.01.00/15

International audience; Geoarchaeological approaches to ancient urban contexts focus on the study of the town as an artefact, and as an artificial and anthropogenic sedimentary basin. In such context the relationship between societies and the geosystem generates diverse and dense pedo-sedimentary formations. The studied scales of such a complex socio-system encompass local geochemical substrate, artificial superficial formations, and relationship between town and hinterland. In the actual conditions of massive and accelerated artificialisation of spaces, the study of those systems can give new clues to better understand the Anthropocene. Different geoarchaeological approaches developed in Europe to study this hybrid urban object are exposed here. From the Iron Age to modern period, they deal with questions of pre-urban topography, social management of material flows, pollutions, occupation of spaces, stratigraphy, and taphonomy. The obtained results underline the diversity of the relations between societies and soils, rivers, hazards in a long-term co-construction of artificial urban systems, which are our heritage now.; L’objet des approches géoarchéologiques de l’urbain est constitué du site, de la ville en tant qu’artefact et bassin artificiel de sédimentation anthropique. Dans ces contextes, les relations entre les sociétés et le géosystème produisent des formations pédo-sédimentaires denses et diverses. Les échelles traitées sont celles d’un socio-système complexe, incluant le substrat pédo-géo-chimique local, les formations superficielles artificielles et les relations avec l’hinterland. Dans un contexte actuel d’artificialisation accéléré des espaces, comprendre ces systèmes peut être une clé pour aborder l’Anthropocène. Différentes approches géoarchéologiques de cet objet urbain hybride, conduites en Europe, sont exposées dans cet article. De l’âge du Fer à la période moderne, elles abordent les questions de topographie préurbaine, de gestion sociale des flux de matériaux, de pollutions, d’occupation des espaces et d’évolution des stratifications. Les résultats montrent la diversité des relations entre les sociétés et les sols, dans une co-construction sur le temps long de systèmes urbains artificiels.

The ubiquitous urban Dark Earths composes a main challenge for urban archaeologists. Due to their homogeneous character they cannot be readily understood based on field data alone. Geoarchaeology (field study and micromorphology) has shown to be particularly well suited to tackle these layers, and to reveal their complex formation histories and the human activities and natural events involved. During the excavations of the site of Sint-Jozefs college in the centre of Aalst (Belgium) a thick dark earth was discovered underneath the remains of the rampart of the 11th century town wall. An interdisciplinary study, involving archaeology, geoarchaeology and phytolith analysis has been performed. It demonstrates that the Dark Earth layer has a long formation history involving pasture and crop growing, intimately mixed with soil processes such as bioturbation and colluviation. The identified activities confirm the rather rural character of the area until the 11th century AD., This article is part of a book edited at the occasion of the Geoarchaeological meeting of Bruges: Soils as records of Past and Present: the geoarchaeological approach. Focus on: is there time for fieldwork today? - Bruges (Belgium), 6 and 7.11.2019. Editors Judit Deák, Carole Ampe and Jari Hinsch Mikkelsen Technical editor Mariebelle Deceuninck English language reviewer Caroline Landsheere Graphic design Frederick Moyaert Printing and binding Die Keure, Bruges