(Table 1) Organic carbon and radiogenic isotopes analysis of DSDP Hole 22-218 sediments
Cobertura |
LATITUDE: 8.007000 * LONGITUDE: 86.282800 * DATE/TIME START: 1972-03-01T00:00:00 * DATE/TIME END: 1972-03-01T00:00:00 * MINIMUM DEPTH, sediment/rock: 6.0 m * MAXIMUM DEPTH, sediment/rock: 766.1 m |
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Data(s) |
30/07/2010
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Resumo |
Modern erosion of the Himalaya, the world's largest mountain range, transfers huge dissolved and particulate loads to the ocean. It plays an important role in the long-term global carbon cycle, mostly through enhanced organic carbon burial in the Bengal Fan. To understand the role of past Himalayan erosion, the influence of changing climate and tectonic on erosion must be determined. Here we use a 12 Myr sedimentary record from the distal Bengal Fan (Deep Sea Drilling Project Site 218) to reconstruct the Mio-Pliocene history of Himalayan erosion. We use carbon stable isotopes (d13C) of bulk organic matter as paleo-environmental proxy and stratigraphic tool. Multi-isotopic - Sr, Nd and Os - data are used as proxies for the source of the sediments deposited in the Bengal Fan over time. d13C values of bulk organic matter shift dramatically towards less depleted values, revealing the widespread Late Miocene (ca. 7.4 Ma) expansion of C4 plants in the basin. Sr, Nd and Os isotopic compositions indicate a rather stable erosion pattern in the Himalaya range during the past 12 Myr. This supports the existence of a strong connection between the southern Tibetan plateau and the Bengal Fan. The tectonic evolution of the Himalaya range and Southern Tibet seems to have been unable to produce large re-organisation of the drainage system. Moreover, our data do not suggest a rapid change of the altitude of the southern Tibetan plateau during the past 12 Myr. Variations in Sr and Nd isotopic compositions around the late Miocene expansion of C4 plants are suggestive of a relative increase in the erosion of High Himalaya Crystalline rock (i.e. a simultaneous reduction of both Transhimalayan batholiths and Lesser Himalaya relative contributions). This could be related to an increase in aridity as suggested by the ecological and sedimentological changes at that time. A reversed trend in Sr and Nd isotopic compositions is observed at the Plio-Pleistocene transition that is likely related to higher precipitation and the development of glaciers in the Himalaya. These almost synchronous moderate changes in erosion pattern and climate changes during the late Miocene and at the Plio-Pleistocene transition support the notion of a dominant control of climate on Himalayan erosion during this time period. However, stable erosion regime during the Pleistocene is suggestive of a limited influence of the glacier development on Himalayan erosion. |
Formato |
text/tab-separated-values, 303 data points |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.786673 doi:10.1594/PANGAEA.786673 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Galy, Valier; France-Lanord, Christian; Peucker-Ehrenbrink, Bernhard; Huyghe, Pascale (2010): Sr-Nd-Os evidence for a stable erosion regime in the Himalaya during the past 12 Myr. Earth and Planetary Science Letters, 290(3-4), 474-480, doi:10.1016/j.epsl.2010.01.004 |
Palavras-Chave | #22-218; AGE; Carbon, organic, total; Deep Sea Drilling Project; delta 13C, organic carbon; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP; epsilon-Neodymium; Glomar Challenger; Indian Ocean//FAN; Leg22; Neodymium 143/Neodymium 144; Neodymium 143/Neodymium 144, error; ODP sample designation; Osmium; Osmium 187/Osmium 188, error; Osmium 187/Osmium 188 ratio; Osmium 188; Sample code/label; Strontium 87/Strontium 86, error; Strontium 87/Strontium 86 ratio |
Tipo |
Dataset |