Search results for "LUS"
showing 10 items of 19536 documents
Phase equilibrium constraints on pre-eruptive conditions of recent felsic explosive volcanism at Pantelleria Island, Italy.
2010
International audience; We present experimental phase equilibria carried out on a pantelleritic bulk-rock composition with a peralkalinity index [PI = molar (Na2O + K2O)/Al2O3] = 1*4, which is representative of the most energetic pumice fall eruption of the resurgent post-caldera volcanism on Pantelleria island. For the explored conditions (P = 25-150 MPa; T = 680-800°C; H2Omelt up to 6 wt %; fO2 ≤ NNO, where NNO is nickel-nickel oxide buffer) clinopyroxene is the liquidus phase followed by alkali feldspar and then quartz. The crystallization of amphibole is limited to temperatures below 700°C. Aenigmatite crystallizes near the liquidus for P ≥ 100 MPa. When clinopyroxene is the sole liquid…
High-resolution spectroscopy and analysis of the V2 + V3 combination band of SF6 in a supersonic jet expansion
2013
International audience; Sulphur hexafluoride is a very strong greenhouse gas whose concentration is increasing in the atmosphere. It is detected through infrared absorption spectroscopy in the strong ν3 fundamental region. Due to the existence of low-lying vibrational states of this molecule, however, many hot bands arise at room temperature and those are still not known. We present here a contribution to the elucidation of this hot band structure, by analysing the ν2 + ν3 combination band. We use a supersonic jet expansion high-resolution spectrum at a rotational temperature of ca. 25 K that was recorded thanks to the Jet-AILES setup at the Source Optimisée de Lumière d'Energie Intermédiai…
Modelling soil moisture at SMOS scale by use of a SVAT model over the Valencia Anchor Station
2010
16 páginas, 9 figuras, 5 tablas.
Pollen and non-pollen palynomorph evidence of medieval farming activities in southwestern Greenland
2010
International audience; Radiocarbon dating, pollen and non-pollen palynomorph analyses from a lake core were used to establish the timing and effects of farming activities around Lake Igaliku, Eastern Settlement, Greenland. The absence of agro-pastoral impact before the medieval colonization by Europeans provides an opportunity to understand the development of farming activity in a pristine landscape. The results show that the first phase of clearance and grazing pressure, without the expansion of the Norse apophyte (native plant, in habitats created by humans) Rumex acetosa type, could have occurred in the 9–10th century A.D. The presence of Norse settlers and livestock is clearly recorded…
Investigating the Local Reservoir Age and Stable Isotopes of Shells from Southeast Arabia
2016
AbstractWe recently started a systematic approach to determine the reservoir age in southeast Arabia and its dependence on mollusk species and their environment. This part of the study concentrates on local reservoir age and stable isotopes of the lagoonal species Terebralia palustris and Anadara uropigimelana at Khor Kalba, Oman Sea. Environmental and nutritive influences on mollusks are reflected in the radiocarbon and stable isotope signal. We found a local reservoir age of A. uropigimelana of about 940 yr and that of T. palustris as 800 yr. Sclerochronological analyses yielded information about seasonality of growth and death in A. uropigimelana. The modern shell of Periglypta reticulat…
Identifying fossil rabbit warrens: Insights from a taphonomical analysis of a modern warren
2016
14 pages; International audience; The European rabbit is a small burrowing mammal that is particularly abundant in Western Europe since the Pleistocene and introduced around the world over the last few centuries. Rabbit bones are regularly recovered from archaeological and palaeontological sites; however, demonstrating their contemporaneity with associated material is often difficult. Additionally, determining the origin of rabbit remains in fossil sites is equally problematic due to the lack of reference collections for natural accumulations. In order to address these issues, we excavated a modern rabbit warren in southwestern France using modern archaeological field methods and techniques…
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…
Late Miocene remains from Venta del Moro (Iberian Peninsula) provide further insights on the dispersal of crocodiles across the late Miocene Tethys
2020
The dispersal of Crocodylus from Africa to Europe during the Miocene is not well understood. A small collection of cranial fragments and postcranial elements from the latest Miocene (6.2 Ma) site of Venta del Moro (Valencia, Spain) have previously been referred to Crocodylus cf. C. checchiai Maccagno, 1947 without accompanying descriptions. Here we describe and figure for the first time the crocodylian remains from Venta del Moro, which represent at least two individuals. Our comparisons indicate that this material clearly does not belong to Diplocynodon or Tomistoma - the only two other crocodylians described so far for the European late Miocene. The material is only tentatively referred t…
Landscape and wood-fuel in Akrotiri (Thera, Greece) during the Bronze Age
2017
Abstract Wood charcoal macroremains originating from the archaeological site of Akrotiri, Thera (Greece) have been analyzed. The results obtained suggest the existence of thermophilous vegetation on the island from the Early Cycladic period right up to the catastrophic eruption of the volcano in the Late Cycladic I period. The comparative evaluation of the results gained from this study and the previous ones indicates that during the Early Cycladic period an open Pinus type brutia/halepensis (Cyprus/Aleppo pine) forest prevailed on the island, accompanied by maquis vegetation. From the Middle Cycladic period and onwards a shift towards open maquis vegetation is observed. At the same time, s…
Dietary evidence from Central Asian Neanderthals: A combined isotope and plant microremains approach at Chagyrskaya Cave (Altai, Russia).
2021
Neanderthals are known primarily from their habitation of Western Eurasia, but they also populated large expanses of Northern Asia for thousands of years. Owing to a sparse archaeological record, relatively little is known about these eastern Neanderthal populations. Unlike in their western range, there are limited zooarchaeological and paleobotanical studies that inform us about the nature of their subsistence. Here, we perform a combined analysis of carbon and nitrogen stable isotopes on bone collagen and microbotanical remains in dental calculus to reconstruct the diet of eastern Neanderthals at Chagyrskaya Cave in the Altai Mountains of Southern Siberia, Russia. Stable isotopes identify…