气候变化领域集成服务门户(CCPortal): Formation of waterfalls by intermittent burial of active faults

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DOI	10.1130/B31743.1
	Formation of waterfalls by intermittent burial of active faults
	Malatesta L.C.; Lamb M.P.
发表日期	2018
ISSN	167606
起始页码	522
结束页码	536
卷号	130 期号:2021-03-04
英文摘要	Waterfalls commonly exist near bounding faults of mountain ranges, where erosional bedrock catchments transition to depositional alluvial fans. We hypothesize that aggradation on alluvial fans can bury active faults, and that the faults accumulate slip in the subsurface to produce a bedrock scarp. Following entrenchment of the alluvial fan, the scarp can be exposed as a waterfall. To explore this hypothesis, we derived a geometric model for waterfall height that depends on alluvial fan length and the relative time scales of (1) tectonic uplift, (2) a forcing mechanism for cycles of fan aggradation and incision, and (3) a response of fan aggradation to changes in sediment flux. We find that the model is consistent with observations at Gower Gulch, Death Valley, California, where a man-made drainage capture event in 1941 caused rapid fan incision and exposed a waterfall at the canyon-fan transition. We also compared the model to 62 waterfalls in 18 catchments of the Death Valley area and found that at least 15 of the waterfalls are best explained by the faultburial mechanism. Using field measurements of grain size and channel geometries, we show that the fault-burial mechanism can produce the observed waterfall heights, measuring 4-19 m, under a uniform climatic forcing scenario requiring variations of 20% in precipitation during the late Pleistocene. The fault-burial mechanism, through the creation of upstream propagating waterfalls, may allow catchment-fan systems to experience frequent cycles of enhanced erosion in catchments and deposition on fans that likely convolve tectonic and climatic signals. © 2017 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/185075
作者单位	Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, United States; Department of Earth and Planetary, Sciences, University of California Santa Cruz, 1154, High Street, Santa Cruz, CA 95064, United States
推荐引用方式 GB/T 7714	Malatesta L.C.,Lamb M.P.. Formation of waterfalls by intermittent burial of active faults[J],2018,130(2021-03-04).
APA	Malatesta L.C.,&Lamb M.P..(2018).Formation of waterfalls by intermittent burial of active faults.Bulletin of the Geological Society of America,130(2021-03-04).
MLA	Malatesta L.C.,et al."Formation of waterfalls by intermittent burial of active faults".Bulletin of the Geological Society of America 130.2021-03-04(2018).