DOI: 10.1016/j.palaeo.2014.09.023
论文题名: Pliocene environmental change in West Africa and the onset of strong NE trade winds (ODP Sites 659 and 658)
作者: Vallé F. ; Dupont L.M. ; Leroy S.A.G. ; Schefuß E. ; Wefer G.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 414 起始页码: 403
结束页码: 414
语种: 英语
英文关键词: NE trade winds
; Pleistocene
; Pliocene
; Pollen
; West Africa
英文摘要: Pliocene vegetation dynamics and climate variability in West Africa have been investigated through pollen and XRF-scanning records obtained from sediment cores of ODP Site 659 (18°N, 21°W). The comparison between total pollen accumulation rates and Ti/Ca ratios, which is strongly correlated with the dust input at the site, showed elevated aeolian transport of pollen during dusty periods. Comparison of the pollen records of ODP Site 659 and the nearby Site 658 resulted in a robust reconstruction of West African vegetation change since the Late Pliocene. Between 3.6 and 3.0. Ma the savannah in West Africa differed in composition from its modern counterpart and was richer in Asteraceae, in particular of the Tribus Cichorieae. Between 3.24 and 3.20. Ma a stable wet period is inferred from the Fe/K ratios, which could stand for a narrower and better specified mid-Pliocene (mid-Piacenzian) warm time slice. The northward extension of woodland and savannah, albeit fluctuating, was generally greater in the Pliocene. NE trade wind vigour increased intermittently around 2.7 and 2.6. Ma, and more or less permanently since 2.5. Ma, as inferred from increased pollen concentrations of trade wind indicators (. Ephedra, Artemisia, Pinus). Our findings link the NE trade wind development with the intensification of the Northern Hemisphere glaciations (iNHG). Prior to the iNHG, little or no systematic relation could be found between sea surface temperatures of the North Atlantic with aridity and dust in West Africa. © 2014 . Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69190
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: MARUM - Center for Marine Environmental Sciences, University of Bremen, Leobenerstr Bremen, Germany; Institute for the Environment, Brunel University London, Uxbridge UB8 1QN, United Kingdom
Recommended Citation:
Vallé F.,Dupont L.M.,Leroy S.A.G.,et al. Pliocene environmental change in West Africa and the onset of strong NE trade winds (ODP Sites 659 and 658)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,414