Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B31941.1 |
Impact of glacial-lake paleofloods on valley development since glacial termination II: A conundrum of hydrology and scale for the lowstand Brahmaputra-Jamuna paleovalley system | |
Pickering, L.1,3; Diamond, M. S.1,7; Goodbred, S. L.1; Grall, C.2; Martin, J. M.3; Palamenghi, L.4; Paola, C.5,6; Schwenk, T.4; Sincavage, R. S.1,8; Spiess, V4 | |
2019 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN
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ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2019 |
卷号 | 131页码:58-70 |
文章类型 | Article |
语种 | 英语 |
国家 | USA; Germany |
英文摘要 | To better define the base of the Brahmaputra River paleovalley, we analyzed an extensive borehole data set from the subaerial Bengal delta and a 255-km-long multichannel seismic survey along the modern river. The data reveal that the paleovalley floor is defined by a gravel unit containing bouldersized clasts up to 30 cm in diameter, deposited after ca. 30 ka but before ca. 9 ka. Paleohydrology during that time and the previous glacial maximum was characterized by a weak monsoon and reduced river discharge, both of which are inconsistent with large valley formation. However, our work indicates that glacial-lake outburst floods sourced from the Tibetan reaches of the Brahmaputra were routed through the lowstand valley, producing megaflood-scale discharge capable of transporting gravel and cannibalizing the valley margins. The timing of these glacial-lake outburst flood-driven discharge events was coincident with valley development and explains the anomalously large width of the valley and basal gravel surface. Despite the underfit scale of Brahmaputra discharge following the last glacial period, a strengthening monsoon and high sediment discharge in the early Holocene subsequently contributed to the efficient infilling of the massive paleovalley by the mid-Holocene. In a sequence stratigraphic context, this work provides an example of a major unconformity that developed late in the eustatic cycle (i.e., during early transgression rather than an earlier, protracted response to sealevel lowering) and in response to a perturbation originating in the catchment instead of changing accommodation in the basin. As such, it represents a geologically instantaneous time surface that can be used as a marker for stratigraphic correlation but one that is not in phase with eustatic sea-level fall. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000454928000004 |
WOS关键词 | INDIAN MONSOON ; SEQUENCE STRATIGRAPHY ; TIBETAN PLATEAU ; DAMMED LAKE ; ALLUVIAL SEQUENCES ; TSANGPO GORGE ; RIVER ; VARIABILITY ; EVOLUTION ; 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/25208 |
专题 | 地球科学 |
作者单位 | 1.Vanderbilt Univ, Dept Earth & Environm Sci, Nashville, TN 37235 USA; 2.Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA; 3.Shell Int Explorat & Prod Inc, Houston, TX 77082 USA; 4.Univ Bremen, Fac Geosci, D-28359 Bremen, Germany; 5.Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 USA; 6.Univ Minnesota, St Anthony Falls Lab, Minneapolis, MN 55455 USA; 7.Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA; 8.Radford Univ, Dept Geol, Radford, VA 24142 USA |
推荐引用方式 GB/T 7714 | Pickering, L.,Diamond, M. S.,Goodbred, S. L.,et al. Impact of glacial-lake paleofloods on valley development since glacial termination II: A conundrum of hydrology and scale for the lowstand Brahmaputra-Jamuna paleovalley system[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2019,131:58-70. |
APA | Pickering, L..,Diamond, M. S..,Goodbred, S. L..,Grall, C..,Martin, J. M..,...&Spiess, V.(2019).Impact of glacial-lake paleofloods on valley development since glacial termination II: A conundrum of hydrology and scale for the lowstand Brahmaputra-Jamuna paleovalley system.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,131,58-70. |
MLA | Pickering, L.,et al."Impact of glacial-lake paleofloods on valley development since glacial termination II: A conundrum of hydrology and scale for the lowstand Brahmaputra-Jamuna paleovalley system".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 131(2019):58-70. |
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