DOI: 10.1016/j.quascirev.2017.04.022
Scopus记录号: 2-s2.0-85018363595
论文题名: Palynological evidence for Holocene climatic and oceanographic changes off western South Africa
作者: Zhao X. ; Dupont L. ; Schefuß E. ; Bouimetarhan I. ; Wefer G.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2017
卷: 165 起始页码: 88
结束页码: 101
语种: 英语
英文关键词: Dinoflagellate cysts
; Holocene
; Paleoceanography
; Paleoenvironment
; West coast of South Africa
Scopus关键词: Geology
; Natural sciences
; Dinoflagellate cysts
; Holocenes
; Paleo-environment
; Paleoceanography
; South Africa
; Nutrients
; Brigantedinium
; Dinophyceae
; Operculodinium centrocarpum
; Protoperidinium americanum
; Spiniferites
英文摘要: Atmospheric and oceanographic interactions between the Atlantic and Indian Oceans influence upwelling in the southern Benguela upwelling system. In order to obtain a better knowledge of paleoceanographic and paleoenvironmental changes in the southern Benguela region during the Holocene, 12 marine surface sediment samples and one gravity core GeoB8331-4 from the Namaqualand mudbelt off the west coast of South Africa have been studied for organic-walled dinoflagellate cysts in high temporal resolution. The results are compared with pollen and geochemical records from the same samples. Our study emphasizes significantly distinct histories in upwelling intensity as well as the influence of fluvial input during the Holocene. Three main phases were identified for the Holocene. High percentages of cysts produced by autotrophic taxa like Operculodinium centrocarpum and Spiniferites spp. indicate warmer and stratified conditions during the early Holocene (9900-8400 cal. yr BP), suggesting reduced upwelling likely due to a northward shift of the southern westerlies. In contrast, the middle Holocene (8400-3100 cal. yr BP) is characterized by a strong increase in heterotrophic taxa in particular Lejeunecysta paratenella and Echinidinium spp. at the expense of autotrophic taxa. This indicates cool and nutrient-rich waters with active upwelling probably caused by a southward shift of the southern westerlies. During the late Holocene (3100 cal. yr BP to modern), Brigantedinium spp. and other abundant taxa interpreted to indicate fluvial nutrient input such as cyst of Protoperidinium americanum and Lejeunecysta oliva imply strong river discharge with high nutrient supply between 3100 and 640 cal. yr BP. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59230
Appears in Collections: 过去全球变化的重建
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作者单位: MARUM - Center for Marine Environmental Sciences, University of Bremen, Leobener Straße, Bremen, Germany
Recommended Citation:
Zhao X.,Dupont L.,Schefuß E.,et al. Palynological evidence for Holocene climatic and oceanographic changes off western South Africa[J]. Quaternary Science Reviews,2017-01-01,165