Title: Geologic map of the southern Fish Creek Range, Eureka and Nye counties, Nevada
Author: Russell V. Di Fiori and Sean P. Long
Year: 2022
Series: Open-File Report 2022-05
Version:
Format: sheet: 33 x 22 inches, cross sections, color; text: 9 pages, color
Scale: 1:15,000
The southern part of the Fish Creek Range is located in central Nevada, ~40 km south of the town of Eureka (fig. 1). Previous studies in the Fish Creek Range (e.g., Merriam, 1967; Hose, 1983; Sans, 1986) have presented differing interpretations of the tectonic significance of Paleozoic, Mesozoic, and Cenozoic rock units exposed in the southern part of the range, including using different naming schemes for Paleozoic sedimentary rock units (e.g., Hose, 1983; Poole et al., 1983) and varying interpretations of the depositional age range and nature (i.e., stratigraphic versus structural) of the upper and lower contacts of the Cretaceous Newark Canyon Formation (NCF) and Paleogene Sheep Pass Formation (e.g., Hose, 1983; Sans, 1986). These Cretaceous and Paleogene sedimentary units are only sparsely exposed in eastern Nevada, and therefore the southern Fish Creek Range is an important field locality that offers a rare opportunity to bracket the timing of Mesozoic and early Cenozoic depositional events. In addition, the southern Fish Creek Range also has been interpreted to lie within the central Nevada thrust belt (CNTB), a system of north-striking, east-vergent thrust faults and folds that branch northward off the Sevier thrust in southern Nevada (fig. 1; e.g., Taylor et al., 1993, 2000). However, to date there have been vastly differing interpretations presented for the geometry, timing, and tectonic significance of contractional structures in the southern Fish Creek Range (e.g., Hose, 1983; Sans, 1986).
The purpose of this study is to present an updated structural and stratigraphic interpretation of rock units in the southern Fish Creek Range. Here, we present a new 1:15,000-scale geologic map, which covers an area of ~21.5 km2 and focuses on the outcrop extent of the NCF and Sheep Pass Formation. This technical report, which is meant to accompany the geologic map, presents revisions to the Paleozoic stratigraphy as mapped by Hose (1983), divides the NCF into four mappable members, and presents an updated view of the structural framework of the range, including documenting a previously unmapped thrust fault. In addition, new U-Pb zircon geochronology presented in Di Fiori et al. (2021) provides additional depositional age constraints on both the NCF and the Sheep Pass Formation.
This geologic map was funded in part by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G20AC00390, 2020.
Suggested Citation:
Di Fiori, R.V., and Long, S.P, 2022, Geologic map of the southern Fish Creek Range, Eureka and Nye counties, Nevada: Nevada Bureau of Mines and Geology Open-File Report 2022-05, scale 1:15,000, 9 p.
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