Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B31546.1 |
Soil development over mud-rich rocks produces landscape-scale erosional instabilities in the northern Gabilan Mesa, California | |
Johnstone, Samuel A.1,6; Chadwick, K. Dana2; Frias, Miguel3,4; Tagliaro, Gabriel3,5; Hilley, George E.1 | |
2017-09-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN |
ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2017 |
卷号 | 129 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | In soil-mantled landscapes, the length of hillslopes is set by the relative efficiency of hillslope transport processes and incision by channelized flows. In cases where rapid channel incision exposes less-weathered, moreresistant rocks, incision should slow, creating a damping feedback that prevents runaway channel expansion. We present observations from the northern Gabilan Mesa (central Coast Ranges, California), which is underlain by mud-rich rocks that provide less resistance to erosion than the soils produced from them. This strength inversion arises because unconfined, mud-rich units of the Pancho Rico Formation undergo a process called slaking, in which pervasive fractures, spaced centimeters apart, develop when subjected to wet-dry cycles. In contrast, consecutive wetting and drying cycles have produced a cohesive regolith with higher tensile strength than the slaked bedrock. Exposure of the relatively weak bedrock may create a positive feedback, where the acceleration of erosion within the bedrock undermines the cohesive regolith and allows channels to expand headward at the expense of hillslopes. Geomorphic mapping reveals numerous channelized features that have incised deeply into bedrock, and crosscutting relationships and topographic analyses indicate that these features have consumed regions of the landscape previously occupied by hillslopes. However, these features are only present in south-flowing drainages, where soil is thinnest and therefore bedrock is most likely to be exposed by increases in erosion rate. Preferential headward expansion of these south-flowing channels has established a profound topographic asymmetry, where southflowing tributaries occupy similar to 75% of drainage basin width. These results suggest that processes operating at the scale of the critical zone, which may be unique to certain rock types, conspire to produce an instability that shapes the morphology of drainage basins. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000409330000015 |
WOS关键词 | DRAINAGE-BASIN EVOLUTION ; STRATH TERRACE FORMATION ; COAST RANGES ; BEDROCK ; VALLEY ; TOPOGRAPHY ; HILLSLOPES ; TECTONICS ; INCISION ; SEDIMENT |
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/24757 |
专题 | 地球科学 |
作者单位 | 1.Stanford Univ, Dept Geol Sci, Stanford, CA 94305 USA; 2.Stanford Univ, Dept Earth Syst Sci, Stanford, CA 94305 USA; 3.Stanford Univ, Dept Geol & Environm Sci, Stanford Undergrad Res Geosci & Engn, Stanford, CA 94305 USA; 4.Univ Wisconsin Madison, Dept Geol Engn, Madison, WI 53706 USA; 5.Univ Texas Austin, Jackson Sch Geosci, Austin, TX 78712 USA; 6.US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA |
推荐引用方式 GB/T 7714 | Johnstone, Samuel A.,Chadwick, K. Dana,Frias, Miguel,et al. Soil development over mud-rich rocks produces landscape-scale erosional instabilities in the northern Gabilan Mesa, California[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2017,129. |
APA | Johnstone, Samuel A.,Chadwick, K. Dana,Frias, Miguel,Tagliaro, Gabriel,&Hilley, George E..(2017).Soil development over mud-rich rocks produces landscape-scale erosional instabilities in the northern Gabilan Mesa, California.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,129. |
MLA | Johnstone, Samuel A.,et al."Soil development over mud-rich rocks produces landscape-scale erosional instabilities in the northern Gabilan Mesa, California".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 129(2017). |
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