Stratigraphic and Structural Relations in Trench Exposures and Geomorphology at the Big Burn, Lily Lake, and Lester Ranch Sites, Bear River Fault Zone, Utah and Wyoming

Scientific Investigations Map 3430
By: , and 

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Abstract

This report provides trench photomosaics, logs and related site information, age data, and earthquake event evidence from three paleoseismic trench sites on the Bear River Fault Zone. Our motivation for studying the Bear River Fault Zone—a nascent normal fault in the Rocky Mountains east of the Basin and Range physiographic province—is twofold: (1) the intriguing conclusion from previous work that the neotectonic history of the fault may have begun in the middle to late Holocene and consists of only two surface-rupturing earthquakes and (2) the question of whether large scarps (>10 meters in height) observed along the fault represent net tectonic displacement, which, given a two-event history, would put the displacements among the largest in the Basin and Range region. In presenting our trench and initial geomorphic interpretations, this report lays the groundwork for further exploration of these issues.

Suggested Citation

Hecker, S., DuRoss, C.B., Schwartz, D.P., Cinti, F.R., Civico, R., Lund, W.R., Hiscock, A.I., West, M.W., Wilcox, T., and Stoller, A.R., 2019, Stratigraphic and structural relations in trench exposures and geomorphology at the Big Burn, Lily Lake, and Lester Ranch sites, Bear River Fault Zone, Utah and Wyoming: U.S. Geological Survey Scientific Investigations Map 3430, 8 p., 3 sheets, https://doi.org/10.3133/sim3430.

ISSN: 2329-132X (online)

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Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Stratigraphic and structural relations in trench exposures and geomorphology at the Big Burn, Lily Lake, and Lester Ranch sites, Bear River Fault Zone, Utah and Wyoming
Series title Scientific Investigations Map
Series number 3430
DOI 10.3133/sim3430
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Earthquake Science Center
Description Report: 13 p.; Sheet 1: 58.03 x 27.83 in.; Sheet 2: 48.68 x 29.19 in.; Sheet 3: 52.58 x 28.94 in.
Country United States
State Utah, Wyoming
Other Geospatial Bear River Fault Zone