نتایج جستجو برای: pliocene
تعداد نتایج: 2942 فیلتر نتایج به سال:
An expansion of C 4 grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more 13 C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C 3 vegetation. To explore this problem I present a compilation of bulk stabl...
S. J. Koenig, A. M. Dolan, B. de Boer, E. J. Stone, D. J. Hill, R. M. DeConto, A. Abe-Ouchi, D. J. Lunt, D. Pollard, A. Quiquet, F. Saito, J. Savage, and R. van de Wal Department of Geosciences, University of Massachusetts, 611 N. Pleasant St, Amherst, MA 01003, USA School of Earth and Environment, Earth and Environment Building, University of Leeds, Leeds, LS2 9JT, UK Department of Earth Scien...
During an interval of the Late Pliocene, referred to here as the mid-Pliocene Warm Period (mPWP; 3.264 to 3.025 million years ago), global mean temperature was similar to that predicted for the end of this century, and atmospheric carbon dioxide concentrations were higher than preindustrial levels. Sea level was also higher than today, implying a significant reduction in the extent of the ice s...
Hadar is well known as one of the most productive early hominin sites in the world. Between 1972 and 1994 a large sample of fossil cercopithecid specimens was collected from Hadar and the nearby sites of Geraru, Ahmado, and Leadu. At least five, and possibly six, species are present in the sample, including two chronological subspecies of Theropithecus oswaldi. T. o. cf. darti is known from the...
[1] Integrated Ocean Drilling Program Expedition 315 recovered cores from accretionary units, which are overlain by cover sequences, at a site on the hanging wall of the mega‐splay fault (C0001), and at a seaward margin of a forearc basin (C0002) in Nankai Trough off Kumano, Japan. In order to investigate the amount and the style of deformation and shortening direction of the accretionary prism...
Ž . Balkan endemic nephropathy BEN is a fatal kidney disease that is known to occur only in clusters of villages in alluvial valleys of tributaries of the Danube River in Bulgaria, Romania, Yugoslavia, Bosnia, and Croatia. The confinement of this disease to a specific geographic area has led to speculation that an environmental factor may be involved in the etiology of BEN. Numerous environment...
Over the last 5 million years, the global climate system has evolved toward a colder mean state, marked by large-amplitude oscillations in continental ice volume. Equatorward expansion of polar waters and strengthening temperature gradients have been detected. However, the response of the mid latitudes and high latitudes of the Southern Hemisphere is not well documented, despite the potential i...
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