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A 200-ka pollen and oxygen-isotopic record from two sediment cores from the eastern Arabian Sea
- Source :
-
Palaeogeography, Palaeoclimatology, Palaeoecology . Nov2004, Vol. 214 Issue 4, p309-321. 13p. - Publication Year :
- 2004
-
Abstract
- We present here a pollen record from the northern Indian Ocean that goes back to 200 ka, the boundary between marine isotopic stages (MIS) 7 and 6. Pollen, oxygen-isotopic composition and organic carbon have been examined for two sediment cores from the eastern Arabian Sea (15°02′N and 71°41′E, 13°16′N and 71°00′E), to reconstruct the long-term palaeoclimate and palaeovegetation of the Indian subcontinent. Oxygen-isotope data suggest that glacial periods (MIS 2, 4 and 6) are characterised by low precipitation because of a weak southwest monsoon and a strong northeast monsoon. In contrast, interglacial periods (MIS 1, 3 and 5) are marked by high fresh water input resulting from a strong southwest monsoon. During the last glacial–interglacial cycle, sea-surface temperature and surface salinity changed as a result of variations in the evaporation–precipitation (E–P) balance. Throughout the core, the dominant pollen types are Poaceae and Chenopodiaceae and/or Amaranthaceae (>50%). Their dominance during glacial periods (MIS 2, 4 and 6) suggests that the climate was cold and dry. This dominance is also suggestive of salinity-tolerant vegetation colonizing large areas near seashore due to lower sea level or high E–P conditions. During interglacial periods (MIS 1, 3 and 5) when there was high precipitation, the arid taxa were sparse, whereas Poaceae and Piperaceae were abundant. Hence, Chenopodiaceae and/or Amaranthaceae and Artemisia are suggestive of cold and arid/semi-arid climate, and Poaceae and Piperaceae of warm and wet conditions. Mangrove pollen is not well represented in the cores. [Copyright &y& Elsevier]
- Subjects :
- *PALYNOLOGY
*POLLINATION
*CHENOPODIACEAE
*WATER levels
*MANGROVE plants
Subjects
Details
- Language :
- English
- ISSN :
- 00310182
- Volume :
- 214
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Palaeogeography, Palaeoclimatology, Palaeoecology
- Publication Type :
- Academic Journal
- Accession number :
- 14959490
- Full Text :
- https://doi.org/10.1016/j.palaeo.2004.07.027