Search results for "geog"
showing 10 items of 13905 documents
The response of a shallow lake and its catchment to Late Glacial climate changes — A case study from eastern Poland
2015
In this study we investigate how climate fluctuation in the Late Glacial period influenced the development of a lake and its catchment located in the East European Plain. We analyzed the sediments of the lake for pollen, subfossil Cladocera, macrofossils and chemical composition. We aimed at disentangling: (1) the climate changes and their limno-ecological responses, (2) temperature dynamics with the use of Cladocera-based transfer function (MJT) and macrofossil-based reconstruction of mean minimum July temperature (MMJT), (3) timing of the response of different proxies to environmental changes. The results of multiproxy analyses explicitly suggest that the main driver for changes in aquati…
Winter climate signal in boreal clastic-biogenic varves : a comprehensive analysis of three varved records from 1890 to 1990 AD with meteorological a…
2017
Clastic-biogenic varves are widely used for reconstructing past climate: in boreal environments, the accumulation of minerogenic clasts on the lake floor is generally considered a proxy for past variations in spring floods reflecting previous winter conditions. However, the physical mechanisms behind this winter climate sensitivity and the influence of catchment type on the varve formation are not fully investigated. Here, we present a winter climate record inferred from the clastic laminae of three lakes located on the region of fine-grained tills in Eastern Finland spanning from AD 1890 to 1990. The minerogenic varve data are compared with instrumental meteorological and hydrological time…
Un assemblage inhabituel d’insectivores au Miocène inférieur du Sud-Ouest de l’Europe : les talpidés et les dimylidés du bassin de Ribesalbes–Alcora …
2019
The Miocene record of talpids and dimylids in south-western Europe is very scarce. In the present work, we study for the first time the talpids and complete the description of the dimylids, already started with a new species of the genus Plesiodimylus from the Ribesalbes–Alcora Basin (MN4, lower Aragonian, early Miocene) by Crespo et al. (2018). The talpids recovered inRibesalbes–Alcora comprise themost common Desmanodon daamsi and Desmanella fejfari, for which the last known occurrence is recorded here. The dimylids comprise the species Plesiodimylus ilercavonicus, which expands the biostratigraphic record of the genus and species and has been found in a new site. On the other hand, we dis…
L’ évolution des assemblages lithiques des niveaux du Paléolithique moyen de l’Abrigo de la Quebrada (Valencia, Espagne)
2018
L’Abrigo de la Quebrada propose une séquence stratigraphique importante, avec neuf niveaux dont sept présentent des preuves d’occupation appartenant au Paléolithique moyen. De plus, l’existence d’un niveau stérile, le VI, séparant les niveaux supérieurs (II à V) des niveaux inférieurs (VII à IX), permet d’évaluer, dans une perspective diachronique, les changements constatés sur les différentes matiàres premières et sur les systémes de débitage employés pour chacune de ces deux grandes phases. Ces donne´ es sont compare´ es a` d’autres sites contemporains, dans le but d’e´valuer les normes technologiques et la gestion des ressources des ne´ andertaliens dans la zone ge´ographique de la re´gi…
The Solutrean - Magdalenian Transition: a view from Iberia
2012
The paper examines the Upper SolutreaneArchaic Magdalenian/Badegoulian succession on the base of lithic and bone tool production, chrono-stratigraphic data and radiocarbon dates from the Cantabrian and Mediterranean regions of Iberia, mainly the areas of Asturias and Valencia (Spain). The discussion considers a reduced number of variables (characteristic stone tools, bone points and decoration techniques) and highlights the elements in common. The analysis concerning the transformation of lithic production at Cova del Parpallo provides new data for the Upper SolutreaneArchaic Magdalenian/ Badegoulian transition.
Bird consumption in the final stage of Cova Negra (Xátiva, Valencia)
2016
This paper publishes the results of the study of bird remains from Cova Negra level IIIb, a level with Middle Palaeolithic industry that corresponds to the upper part of the sequence, where 247 bird remains from 18 species have been found. Doves and corvidae, particularly choughs (Pyrrhocorax sp.), are the species most frequently found. A substantial part of the remains analyzed displays human manipulation and consumption evidence, a clear indication of bird hunting and consumption by Neardental populations. The manipulation process and consumption of birds, in the context of Neanderthals' predatory activity during the final period of occupation of the site, is described in this paper. Furt…
Landscape instability at the end of MIS 3 in western Central Europe : evidence from a multi proxy study on a Loess-Palaeosol-Sequence from the easter…
2019
Abstract The Lower Rhine Embayment hosts important Loess-Palaeosol-Sequences (LPS) within the western European loess belt yielding valuable information on landscape evolution and palaeoclimatic dynamics. The study focusses on the palaeoenvironmental development based on a LPS from the eastern shoulder of the Lower Rhine Embayment (Dusseldorf-Grafenberg). The palaeoenvironmental development within the study area is presented and discussed based on high-resolution grain size analyses, selected environmental magnetic parameters, and geochemical analyses complemented by luminescence age estimates. Differences in grain size distribution (ΔGSD) as well as the U-ratio clearly reflect main stratigr…
Evidence of aerial volcanic activity during the Valanginian along the northern Tethys margin.
2009
7 pages; International audience; Stratigraphic measurement and sampling on three sections (Vergol, La Charce, and Montclus) through Valanginian deposits from the Vocontian Basin (southeastern France) reveals the occurrence of centimetre thick ochre-coloured layers, which can be correlated from one section to another. At least twelve of these are identified in sediments dated from the Pertransiens to Furcillata ammonite Zones. These horizons appear similar to previously described Oxfordian and Aptian bentonites, also from the Vocontian Basin. Clay-mineralogical and geochemical data are similar in the Valanginian ochre horizons and their enclosing marls except in one of these that shows a cla…
Environmental and climatic controls of the clay mineralogy of Albian deposits in the Paris and Vocontian basins (France)
2020
18 pages; International audience; High-resolution clay mineral analyses were performed on lower and middle Albian deposits from the Paris and Vocontian basins in order to specify the weathering conditions that prevailed at that time. The clay mineral assemblages are composed of small proportions of chlorite and vermiculitic clays associated with abundant illite, R0 type illite-smectite mixed-layers (smectite) and kaolinite. Clay minerals originated from the physical alteration and chemical weathering of rocks and soils outcropping on the Variscan massifs bordering the studied areas. In the Paris Basin, the covariation of illite and kaolinite suggests the reworking of these latter minerals f…
Reappraisal of some species of the giant galericine Deinogalerix (Mammalia, Eulipotyphla, Erinaceomorpha, Erinaceidae) from the Miocene of south-east…
2019
A revision of the remains of Deinogalerix from the Terre Rosse of Gargano, stored at the Department of Earth Sciences of Florence, improved our knowledge of the genus. The goals of this study are to clear the taxonomic status of the specimens and to tackle several issues connected with the evolutionary relationships of the different species. The sample of dental remains of Deinogalerix freudenthali provides new information, which confirms that this species belongs to the most primitive members of the genus, alongside D. masinii. It is now clear that D. freudenthali is very close to the hypothetical ancestor of all other Gargano species, except D. masinii. Nonetheless, the oldest fissures of…