气候变化领域集成服务门户(CCPortal): Conglomerate recycling in the Himalayan foreland basin: Implications for grain size and provenance

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DOI	10.1130/B35334.1
	Conglomerate recycling in the Himalayan foreland basin: Implications for grain size and provenance
	Quick L.; Sinclair H.D.; Attal M.; Singh V.
发表日期	2020
ISSN	167606
起始页码	1639
结束页码	1656
卷号	132 期号:2021-07-08
英文摘要	The nature of coarse sediment in rivers emerging from mountain ranges determines rates of downstream fining, the position of the gravel-sand transition, sediment entrainment thresholds, and channel morphologies. Additionally, in the stratigraphic record, clast size distributions and lithologies are used to reconstruct paleo-hydraulic conditions and source area provenance. Using Himalayan rivers, we demonstrate that the signal of first-generation clasts derived from the hinterland of a mountain range can be significantly altered by recycling older, structurally exhumed foreland deposits. The Siwalik foothills of the Himalaya comprise Neogene fluvial sandstones and quartzite-rich conglomerates with well-rounded clasts that were deposited in the Indo-Gangetic foreland basin and later exhumed by erosion, following uplift along the Himalayan mountain front. Mass balance calculations reveal that the Upper Siwalik conglomerate may contribute a significant proportion of the total gravel flux exported from the main Himalayan catchments (up to 100%) despite forming <1% of the catchment geology. Three end-member catchments with variable proportions of gravel flux from Siwalik conglomerates are analyzed to test for the effects of conglomerate recycling. Catchments that recycle the most Upper Siwalik conglomerate form quartzite-rich gravel bars comprising well-rounded pebbles and a narrow grain size distribution, mimicking the characteristics of the Upper Siwalik conglomerate. Conversely, catchments that recycle the least Upper Siwalik conglomerate form gravel bars with a range of Himalayan lithologies, angular quartzite pebbles and a wider grain size distribution. This study highlights that recycling of quartzite-rich conglomerate can dramatically modify the flux, lithology, grain size, and shape of gravel entering the Indo-Gangetic Plain. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184755
作者单位	School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, United Kingdom; Department of Geology, University of Delhi, Delhi, 110007, India
推荐引用方式 GB/T 7714	Quick L.,Sinclair H.D.,Attal M.,et al. Conglomerate recycling in the Himalayan foreland basin: Implications for grain size and provenance[J],2020,132(2021-07-08).
APA	Quick L.,Sinclair H.D.,Attal M.,&Singh V..(2020).Conglomerate recycling in the Himalayan foreland basin: Implications for grain size and provenance.Bulletin of the Geological Society of America,132(2021-07-08).
MLA	Quick L.,et al."Conglomerate recycling in the Himalayan foreland basin: Implications for grain size and provenance".Bulletin of the Geological Society of America 132.2021-07-08(2020).