Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2019GL085576 |
Oxygen Isotopes in Authigenic Clay Minerals: Toward Building a Reliable Salinity Proxy | |
Gebregiorgis, D.1; Deocampo, D. M.1; Longstaffe, F. J.2; Simpson, A.1; Ashley, G. M.3; Beverly, E. J.4; Delaney, J. S.3; Cuadros, J.5 | |
2020-02-16 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS
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ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2020 |
卷号 | 47期号:3 |
文章类型 | Article |
语种 | 英语 |
国家 | USA; Canada; England |
英文摘要 | Most clay minerals in sedimentary environments have traditionally been considered to be of detrital origin, but under certain conditions, authigenic clay minerals can form at low temperature through the transformation of precursor clays or as direct precipitates from lake water. Such clay minerals can hold important information about the prevailing climatic conditions during the time of deposition. We present the first quantitative reconstruction of salinity in paleolake Olduvai based on the oxygen-isotope composition of authigenic clay minerals. We provide a framework illustrating that the isotopic signature of authigenic lacustrine clay minerals is related to the isotopic composition of paleo-waters, and hence to paleosalinity. This new paleosalinity proxy shows that the early Pleistocene East African monsoon was driven by combinations of precession and obliquity forcing and subsequent changes in tropical sea surface temperatures. Such quantitative lacustrine paleosalinity estimates provide a new direction of research for modeling ecosystem change based on an ecologically relevant parameter. Plain Language Summary Lake sediments contain a rich archive of information about past climate change. Clay minerals in such sediments, in particular, can potentially provide important insight into changes in humidity and aridity in the terrestrial environment by recording changes in precipitation as reflected in lake salinity. Until now, the climate records possibly provided by such clays have not been studied in detail. Here, we have used the oxygen-isotope compositions of clay minerals formed in lake water to investigate past salinity changes in paleolake Olduvai during the early Pleistocene Epoch (similar to 1800-1920 kyr). Isotopes are varieties of an element that have different masses. The two isotopes of oxygen in clay minerals that we measured reflect the lake water composition from which they formed. The isotopic ratios of the lake water, in turn, reflect in predictable ways the extent of lake water evaporation and associated changes in salinity. We interpret the lake salinity changes to reflect changes in intensity of the East African monsoon. We show that the weakening or strengthening of the early Pleistocene East African monsoon was related to changes in the Earth's orbit. This relationship involves complex pathways related to changes in sea surface temperature in the ancient tropical oceans. |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000529107400071 |
WOS关键词 | OLDUVAI GORGE ; VARIABILITY ; LAKE ; GEOCHEMISTRY ; NORTHERN ; TANZANIA ; RAINFALL ; HISTORY ; CLIMATE |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/279602 |
专题 | 气候变化 |
作者单位 | 1.Georgia State Univ, Dept Geosci, Atlanta, GA 30303 USA; 2.Univ Western Ontario, Dept Earth Sci, London, ON, Canada; 3.Rutgers State Univ, Dept Earth & Planetary Sci, Piscataway, NJ USA; 4.Univ Houston, Dept Earth & Atmospher Sci, Houston, TX USA; 5.Nat Hist Museum, Dept Earth Sci, London, England |
推荐引用方式 GB/T 7714 | Gebregiorgis, D.,Deocampo, D. M.,Longstaffe, F. J.,et al. Oxygen Isotopes in Authigenic Clay Minerals: Toward Building a Reliable Salinity Proxy[J]. GEOPHYSICAL RESEARCH LETTERS,2020,47(3). |
APA | Gebregiorgis, D..,Deocampo, D. M..,Longstaffe, F. J..,Simpson, A..,Ashley, G. M..,...&Cuadros, J..(2020).Oxygen Isotopes in Authigenic Clay Minerals: Toward Building a Reliable Salinity Proxy.GEOPHYSICAL RESEARCH LETTERS,47(3). |
MLA | Gebregiorgis, D.,et al."Oxygen Isotopes in Authigenic Clay Minerals: Toward Building a Reliable Salinity Proxy".GEOPHYSICAL RESEARCH LETTERS 47.3(2020). |
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