Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/S0031-0182(98)90052-9 |
Late quaternary precessional cycles of terrigenous sediment input off the Norte Chico, Chile (27.5 degrees S) and palaeoclimatic implications | |
Lamy, F; Hebbeln, D; Wefer, G | |
通讯作者 | Lamy, F |
来源期刊 | PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
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ISSN | 0031-0182 |
EISSN | 1872-616X |
出版年 | 1998 |
卷号 | 141期号:3-4页码:233-251 |
英文摘要 | The palaeoclimatic conditions during the Last Glacial Maximum (LGM) of southern South America and especially latitudinal shifts of the southern westerly wind belt are still discussed controversially. Longer palaeoclimatic records covering the Late Quaternary are rare. A particularly sensitive area to Late Quaternary climatic changes is the Norte Chico, northern Chile, because of its extreme climatic gradients. Small shifts of the present climatic zonation could cause significant variations of the terrestrial sedimentary environment which would be recorded in marine terrigenous sediments. To unveil the history of shifting climatic zones in northern Chile, we present a sedimentological study of a marine sediment core (GeoB 3375-1) from the continental slope off the Norte Chico (27.5 degrees S). Sedimentological investigations include bulk- and silt grain-size determinations by sieving, Atterberg separation, and detailed SediGraph analyses. Additionally, clay mineralogical parameters were obtained by X-ray diffraction methods. The C-14-dated core, covering the time span from approximately 10,000 to 120,000 cal. yr B.P., consists of hemipelagic sediments. Terrigenous sedimentological parameters reveal a strong cyclicity, which is interpreted in terms of variations of sediment provenance, modifications of the terrestrial weathering regimes, and modes of sediment input to the ocean. These interpretations imply cyclic variations between comparatively arid climates and more humid conditions with seasonal precipitation for northern Chile (27.5 degrees S) through the Late Quaternary. The cyclicity of the terrigenous sediment parameters is strongly dominated by precessional cycles. For the palaeoclimatic signal, this means that more humid conditions coincide with maxima of the precession index, as e.g. during the LGM. Higher seasonal precipitation for this part of Chile is most likely derived from frontal winter rain of the Southern Westerlies. Thus, the data presented here favour not only an equatorward shift of this atmospheric circulation system during the LGM, but also precession-controlled latitudinal movements throughout the Late Quaternary. Precessional forcing of latitudinal movements of the westerly atmospheric circulation system may be conceivable through teleconnections to the Northern Hemisphere monsoonal system in the Atlantic Ocean region. (C) 1998 Elsevier Science B.V. All rights reserved. |
英文关键词 | Chile elastic sediments palaeoclimatology quaternary cycles precession |
类型 | Article |
语种 | 英语 |
国家 | Germany |
收录类别 | SCI-E |
WOS记录号 | WOS:000074693900004 |
WOS关键词 | LAST GLACIAL MAXIMUM ; SOUTHERN WESTERLIES ; LATE PLEISTOCENE ; ATLANTIC ; CLIMATE ; TRENCH ; CLAY ; PARAMETERS ; EVOLUTION ; AMERICA |
WOS类目 | Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology |
WOS研究方向 | Physical Geography ; Geology ; Paleontology |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/136475 |
作者单位 | (1)Univ Bremen, Fachbereich Geowissensch, D-28334 Bremen, Germany |
推荐引用方式 GB/T 7714 | Lamy, F,Hebbeln, D,Wefer, G. Late quaternary precessional cycles of terrigenous sediment input off the Norte Chico, Chile (27.5 degrees S) and palaeoclimatic implications[J],1998,141(3-4):233-251. |
APA | Lamy, F,Hebbeln, D,&Wefer, G.(1998).Late quaternary precessional cycles of terrigenous sediment input off the Norte Chico, Chile (27.5 degrees S) and palaeoclimatic implications.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,141(3-4),233-251. |
MLA | Lamy, F,et al."Late quaternary precessional cycles of terrigenous sediment input off the Norte Chico, Chile (27.5 degrees S) and palaeoclimatic implications".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 141.3-4(1998):233-251. |
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