Search results for "ISC"
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Oxygen isotope compositions of phosphate from arvicoline teeth and Quaternary climatic changes, Gigny, French Jura
2004
Oxygen isotope compositions of biogenic phosphates from mammals are widely used as proxies of the isotopic compositions of meteoric waters that are roughly linearly related to the air temperature at high- and mid-latitudes. An oxygen isotope fractionation equation was determined by using present-day European arvicoline (rodents) tooth phosphate: δ18Op = 20.98(±0.59) + 0.572(±0.065) δ18Ow. This fractionation equation was applied to the Late Pleistocene karstic sequence of Gigny, French Jura. Comparison between the oxygen isotope compositions of arvicoline tooth phosphate and Greenland ice core records suggests to reconsider the previously established hypothetical chronology of the sequence. …
Carbon and oxygen stable isotope compositions of late Pleistocene mammal teeth from dolines of Ajoie (Northwestern Switzerland)
2014
AbstractFossils of megaherbivores from eight late Pleistocene 14C- and OSL-dated doline infillings of Ajoie (NW Switzerland) were discovered along the Transjurane highway in the Swiss Jura. Carbon and oxygen analyses of enamel were performed on forty-six teeth of large mammals (Equus germanicus, Mammuthus primigenius, Coelodonta antiquitatis, and Bison priscus), coming from one doline in Boncourt (~ 80 ka, marine oxygen isotope stage MIS5a) and seven in Courtedoux (51–27 ka, late MIS3), in order to reconstruct the paleoclimatic and paleoenvironmental conditions of the region. Similar enamel δ13C values for both periods, ranging from − 14.5 to − 9.2‰, indicate that the megaherbivores lived i…
Precise dating of the Middle-to-Upper Paleolithic transition in Murcia (Spain) supports late Neandertal persistence in Iberia
2017
Abstract The late persistence in Southern Iberia of a Neandertal-associated Middle Paleolithic is supported by the archeological stratigraphy and the radiocarbon and luminescence dating of three newly excavated localities in the Mula basin of Murcia (Spain). At Cueva Anton, Mousterian layer I-k can be no more than 37,100 years-old. At La Boja, the basal Aurignacian can be no less than 36,500 years-old. The regional Middle-to-Upper Paleolithic transition process is thereby bounded to the first half of the 37th millennium Before Present, in agreement with evidence from Andalusia, Gibraltar and Portugal. This chronology represents a lag of minimally 3000 years with the rest of Europe, where th…
The sedimentary and remote-sensing reflection of biomass burning in Europe
2018
Aim: We provide the first European-scale geospatial training set relating the charcoal signal in surface lake sediments to fire parameters (number, intensity and area) recorded by satellite moderate resolution imaging spectroradiometer (MODIS) sensors. Our calibration is intended for quantitative reconstructions of key fire-regime parameters by using sediment sequences of microscopic (MIC from pollen slides, particles 10-500 µm) and macroscopic charcoal (MAC from sieves, particles > 100 µm). Location: North-south and east-west transects across Europe, covering the mediterranean, temperate, alpine, boreal and steppe biomes. Time period: Lake sediments and MODIS active fire and burned area…
Holocene climate and seasonality of shell collection at the Dundas Islands Group, northern British Columbia, Canada—A bivalve sclerochronological app…
2013
article i nfo To analyze environmental changes and the seasonality of shell collection in British Columbia during the Ho- locene, oxygen isotopes were measured from modern and archeological (1337-7438 cal yr BP) shells of the butter clam Saxidomus gigantea. 1697 discrete isotope samples were taken from two modern and 27 arche- ological shells with a high temporal resolution (sub-seasonal up to daily). Archeological shells were collected from five shell midden sites on the Dundas Islands Group, northern British Columbia, Canada. The oxygen iso- tope data reveal clear annual cycles, with the most positive δ 18 Oshell values occurring during the cold season (slower growth, annual growth line f…
Summer air temperature, reconstructions from the last glacial stage based on rodents from the site Taillis-des-Coteaux (Vienne), Western France.
2014
AbstractThe oxygen isotope composition of phosphate from tooth enamel of rodents (δ18Op) constitutes a valuable proxy to reconstruct past air temperatures in continental environments. This method has been applied to rodent dental remains from three genera, Arvicola sp., Microtus sp. and Dicrostonyx sp., coming from Taillis-des-Coteaux, Vienne, France. This archaeological site contains an exceptionally preserved sedimentary sequence spanning almost the whole Upper Palaeolithic, including seven stratigraphic layers dated from 35 to 17 cal ka BP. The abundant presence of rodent remains offers the opportunity to quantify the climatic fluctuations coeval of the various stages of human occupation…
High-frequency climate fluctuations over the last deglaciation in the Alboran Sea, Western Mediterranean: Evidence from calcareous plankton assemblag…
2018
Abstract A high resolution study, with a centennial scale resolution, has been performed on the calcareous plankton assemblage (coccolithophores and planktonic foraminifera) at Ocean Drilling Program Site 976, Alboran Sea (Western Mediterranean), focusing on the interval between 20 and 9 ka, in order to reconstruct changes in surface and subsurface water dynamics and productivity. The biotic surface water proxies integrate the extremely detailed (multi-decadal scale) geochemical data set and the pollen record already available at the core, thus providing a complete paleoenvironmental/paleoceanographic reconstruction. The results highlight the sensitivity of the calcareous plankton in record…
An intractable climate archive — Sclerochronological and shell oxygen isotope analyses of the Pacific geoduck, Panopea abrupta (bivalve mollusk) from…
2008
Abstract Annual growth increment patterns of cardinal teeth (CT) of Panopea abrupta (Conrad) can reportedly provide information about past climate variations. However, little is known about the intra-annual timing and rate of shell growth necessary to interpret such records. In addition, it remains unclear whether actual temperatures can be reliably inferred from δ18O values of geoduck {goo'e-duk} shells. This study compared high-resolution environmental records (hourly to monthly resolved temperature, bi-weekly to monthly δ18Owater and salinity data) with temperatures reconstructed from oxygen isotope values of the outer shell layer (Tδ18OOSL) and cardinal tooth portions (Tδ18OCT) of diffe…
Du Néolithique récent à l’âge du Bronze dans le Centre Nord de la France : les étapes de l’évolution chrono-culturelle
2011
Die seit 2001 im Rahmen eines PCR (Programme Collectif Régional) durchgeführte Gemeinschaftsarbeit über das Ende des Neolithikums und den Beginns der Bronzezeit im Zentrum Nordfrankreichs führt heute zu einer neuen Periodisierung der Zeit zwischen 3600 und 1800 v. Chr. in acht Etappen. Obwohl, insbesondere bezüglich der Transition zwischen dem Mittel-und dem Jungneolithikum einerseits und dem Jung-und dem Endneolithikum andererseits, auch weiterhin einige Lücken bestehen, erlaubt dieser präzisere Rahmen die Hauptetappen im Zentrum Nordfrankreichs mit denen der benachbarten Regionen zu synchronisieren, um eine dynamischere Vision der kulturellen Phänomene vorzuschlagen.
Mineral soil composition interfacing archaeology and chemistry
2016
Abstract In the last decade, different soil types have been analysed to evaluate the effect of human activities from an archaeological point of view. In particular, in the last few years, tremendous advances have been made in sample preparation and analytical methods used in archaeological soil analyses. However, there is still a need to set standardized protocols to achieve different archaeological goals. Therefore, in this study, the analytical methods available to study archaeological soils have been reviewed together with a critical discussion on the challenging archaeological questions, which could be answered by determining their mineral composition. Data on trace elements and rare ea…