Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1016/j.epsl.2016.11.017 |
Short-lived increase in erosion during the African Humid Period: Evidence from the northern Kenya Rift | |
Garcin, Yannick1; Schildgen, Taylor F.1,2; Acosta, Veronica Torres1; Melnick, Daniel1,3; Guillemoteau, Julien1; Willenbring, Jane4; Strecker, Manfred R.1 | |
通讯作者 | Garcin, Yannick |
来源期刊 | EARTH AND PLANETARY SCIENCE LETTERS
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ISSN | 0012-821X |
EISSN | 1385-013X |
出版年 | 2017 |
卷号 | 459页码:58-69 |
英文摘要 | The African Humid Period (AHP) between similar to 15 and 5.5 cal. kyr BP caused major environmental change in East Africa, including filling of the Suguta Valley in the northern Kenya Rift with an extensive (similar to 2150 km(2)), deep (similar to 300 m) lake. Interfingering fluvio-lacustrine deposits of the Baragoi paleo-delta provide insights into the lake-level history and how erosion rates changed during this time, as revealed by delta-volume estimates and the concentration of cosmogenic Be-10 in fluvial sand. Erosion rates derived from delta-volume estimates range from 0.019 to 0.03 mm yr(-1). Be-10-derived paleo-erosion rates at similar to 11.8 cal. kyr BP ranged from 0.035 to 0.086 mm yr(-1), and were 2.7 to 6.6 times faster than at present. In contrast, at similar to 8.7 cal. kyr BP, erosion rates were only 1.8 times faster than at present. Because Be-10-derived erosion rates integrate over several millennia; we modeled the erosion-rate history that best explains the 10Be data using established non-linear equations that describe in situ cosmogenic isotope production and decay. Two models with different temporal constraints (15-6.7 and 12-6.7 kyr) suggest erosion rates that were 25 to 300 times higher than the initial erosion rate (pre-delta formation). That pulse of high erosion rates was short (similar to 4 kyr or less) and must have been followed by a rapid decrease in rates while climate remained humid to reach the modern Be-10-based erosion rate of,similar to 0.013 mm yr(-1). Our simulations also flag the two highest Be-10-derived erosion rates at 11.8 kyr BP related to nonuniform catchment erosion. These changes in erosion rates and processes during the AHP may reflect a strong increase in precipitation, runoff, and erosivity at the arid-to-humid transition either at 15 or similar to 12 cal. kyr BP, before the landscape stabilized again, possibly due to increased soil production and denser vegetation. (C) 2016 Elsevier B.V. All rights reserved. |
英文关键词 | northern Kenya Rift Baragoi paleo-delta African Humid Period erosion Be-10 |
类型 | Article |
语种 | 英语 |
国家 | Germany ; Chile ; USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000393006500006 |
WOS关键词 | COSMOGENIC NUCLIDES ; VEGETATION COVER ; DENUDATION RATES ; CLIMATE-CHANGE ; EAST-AFRICA ; HALF-LIFE ; SEDIMENT ; BE-10 ; BASIN ; SUGUTA |
WOS类目 | Geochemistry & Geophysics |
WOS研究方向 | Geochemistry & Geophysics |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/198324 |
作者单位 | 1.Univ Potsdam, Inst Erd & Umweltwissensch, Karl Liebknecht Str 24,Haus 27, D-14476 Potsdam, Germany; 2.Helmholtz Zentrum Potsdam, Deutsch GeoForschungsZentrum GFZ, Telegrafenberg Potsdam, Germany; 3.Univ Austral Chile, Inst Ciencias Tierra, Casilla 567, Valdivia, Chile; 4.Univ Calif San Diego, Scripps Inst Oceanog, Earth Div, La Jolla, CA 92093 USA |
推荐引用方式 GB/T 7714 | Garcin, Yannick,Schildgen, Taylor F.,Acosta, Veronica Torres,et al. Short-lived increase in erosion during the African Humid Period: Evidence from the northern Kenya Rift[J],2017,459:58-69. |
APA | Garcin, Yannick.,Schildgen, Taylor F..,Acosta, Veronica Torres.,Melnick, Daniel.,Guillemoteau, Julien.,...&Strecker, Manfred R..(2017).Short-lived increase in erosion during the African Humid Period: Evidence from the northern Kenya Rift.EARTH AND PLANETARY SCIENCE LETTERS,459,58-69. |
MLA | Garcin, Yannick,et al."Short-lived increase in erosion during the African Humid Period: Evidence from the northern Kenya Rift".EARTH AND PLANETARY SCIENCE LETTERS 459(2017):58-69. |
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