Search results for "LAND"
showing 10 items of 9939 documents
Flore du Jurassique basal de la ville de Mende (Lozère) : synthèse des gisements historiques, nouvelles données sédimentologiques, paléontologiques e…
2019
Resume Au cours du XXe siecle, la majorite des sites a plantes fossiles (Hettangien–Sinemurien) de la ville de Mende ont disparu a cause d’une importante urbanisation ou bien sont tombes dans l’oubli. Cet article presente une synthese des gisements a vegetaux fossiles, depuis leur decouverte au XIXe siecle jusqu’aux campagnes de prospection recentes. De nouvelles donnees lithostratigraphiques et paleobotaniques sont apportees pour deux sites historiques (le Ravin del Pouset et le Petit Seminaire), ainsi que deux localites fossiliferes dernierement decouvertes (route du Causse-d’Auge et route de Gardes). Cette etude revele la diversite des lithofacies contenant les plantes (dolomudstone, mar…
The Late Ordovician glacial sedimentary system of the North Gondwana platform.
2009
International audience; The Late Ordovician (Hirnantian) glaciation is examined through the North Gondwana record. This domain extended from southern high palaeo-latitudes (southeastern Mauritania, Niger) to northern lower palaeo-latitudes (Morocco, Turkey) and covered a more than 4000 km-wide section perpendicular to ice-flow lines. A major mid-Hirnantian deglaciation event subdividing the Hirnantian glaciation in two first-order cycles is recognised. As best illustrated by the glacial record in western Libya, each cycle comprises 2-3 glacial phases separated by ice-front retreats several hundreds kilometres to the south. From ice-proximal to ice-distal regions, the number of glacial surfa…
Five centuries of Central European temperature extremes reconstructed from tree-ring density and documentary evidence
2010
Future climate change will likely influence the frequency and intensity of weather extremes. As such events are by definition rare, long records are required to understand their characteristics, drivers, and consequences on ecology and society. Herein we provide a unique perspective on regional-scale temperature extremes over the past millennium, using three tree-ring maximum latewood density (MXD) chronologies from higher elevations in the European Alps. We verify the tree-ring-based extremes using documentary evidences from Switzerland, the Czech Republic, and Central Europe that allowed the identification of 44 summer extremes over the 1550-2003 period. These events include cold temperat…
Experimental socioecology: Integrative science for anthropocene landscape dynamics
2016
Abstract The emergence of coupled natural and human landscapes marked a transformative interval in the human past that set our species on the road to the urbanized, industrial world in which we live. This emergence enabled technologies and social institutions responsible for human-natural couplings in domains beyond rural, agricultural settings. The Mediterranean Landscape Dynamics Project (MedLand) is studying the interacting social and biophysical processes associated with these novel socioecological systems and their long-term consequences using a new form of 'experimental socioecology' made possible by recent advances in computation. We briefly describe the MedLand modeling laboratory, …
Estimating “land use heritage” to model changes in archaeological settlement patterns
2016
International audience; In this paper, we present a method to calculate a “land use heritage map” based on the concept of “memory of landscape”. Such a map can be seen as one variable among others influencing site location preference, and can be used as input for predictive models. The computed values equate to an index of long-term land use intensity. We will first discuss the method used for creating the land use heritage map, for which kernel density estimates are used.We will then present the use of these land use heritage maps for site location analysis in two study areas in SE France. Earlier analyses showed that the influence of the natural environment on settlement location choice i…
High-resolution geochemical and biotic records of the Tethyan 'Bonarelli Level' (OAE2, latest Cenomanian) from the Calabianca-Guidaloca composite sec…
2004
Abstract High-resolution micropalaeontological and chemostratigraphic records for the upper Cenomanian portion of the Calabianca–Guidaloca composite section (NW Sicily) provide new insight into the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean. The Bonarelli Level equivalent was identified on the basis of lithology and well constrained by calcareous plankton biostratigraphy and radiolarian assemblages, as well as by the δ 13 C curve showing a marked positive excursion (up to 4.7‰). The Bonarelli Level equivalent deposition is characterized by highly eutrophic conditions as testified by radiolarian proliferation. Black shale samples from the Calabianca–Guidaloca composi…
Dental calculus indicates widespread plant use within the stable Neanderthal dietary niche.
2018
The ecology of Neanderthals is a pressing question in the study of hominin evolution. Diet appears to have played a prominent role in their adaptation to Eurasia. Based on isotope and zooarchaeological studies, Neanderthal diet has been reconstructed as heavily meat-based and generally similar across different environments. This image persists, despite recent studies suggesting more plant use and more variation. However, we have only a fragmentary picture of their dietary ecology, and how it may have varied among habitats, because we lack broad and environmentally representative information about their use of plants and other foods. To address the problem, we examined the plant microremains…
Smithian shoreline migrations and depositional settings in Timpoweap Canyon (Early Triassic, Utah, USA).
2014
AbstractIn Timpoweap Canyon near Hurricane (Utah, USA), spectacular outcrop conditions of Early Triassic rocks document the geometric relationships between a massive Smithian fenestral-microbial unit and underlying, lateral and overlying sedimentary units. This allows us to reconstruct the evolution of depositional environments and high-frequency relative sea-level fluctuations in the studied area. Depositional environments evolved from a coastal plain with continental deposits to peritidal settings with fenestral-microbial limestones, which are overlain by intertidal to shallow subtidal marine bioclastic limestones. This transgressive trend of a large-scale depositional sequence marks a lo…
Advances in Cretaceous palaeontology and stratigraphy – Christopher John Wood Memorial Volume; editors' preface
2018
Abstract In the last week of January 2016, the ‘Cretaceous community’ lost another of their prominent members, Chris Wood. During recent decades, Chris had been active in the United Kingdom as well as in mainland Europe, particularly in Germany and Poland. Several years ago he had been forced to leave the ranks of Associate Editors with Cretaceous Research , due to a severe illness that he was adamant to overcome. Later in 2016, two of us, fellow editors with that journal for a number of years, with the help of Rory Mortimore, approached former colleagues and friends of Chris's to contribute to a special issue. From the start, the idea has been to cover all aspects of Cretaceous stratigraph…
Unravelling extrinsic and intrinsic factors of the early Palaeozoic diversification of blastozoan echinoderms
2010
19 pages; International audience; The Subphylum Blastozoa represents more than one third of the early Palaeozoic echinoderm fauna. A comprehensive database including all records of blastozoans was built to provide quantitative analyses of palaeogeography and diversity patterns and processes, for the 10 classes currently included in this subphylum during the early Palaeozoic. The global pattern of taxonomic diversity shows two peaks during the Cambrian Series 3 and the Late Ordovician intervals. In Cambrian times, the high taxonomic diversity seems to be related with a high turnover rate and a high endemicity of blastozoan genera, whereas in Ordovician times, the rise in diversity is associa…