Alexandria Digital Research Library

Structural evolution of the central schell creek range, White Pine county, Nevada

Author:
Norman, Bryan Wells
Degree Grantor:
University of California, Santa Barbara. Geological Sciences
Degree Supervisor:
Philip B. Gans
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2013
Issued Date:
2013
Topics:
Geology
Keywords:
Detachment fault
Schell Creek Range
Extension
Accommodation Zone
Snake Range
Genres:
Online resources and Dissertations, Academic
Dissertation:
M.S.--University of California, Santa Barbara, 2013
Description:

The central Schell Creek Range (SCR) in eastern Nevada records some of the oldest extensional faulting in the eastern Great Basin. The geometries and kinematics of these early normal faults are poorly documented in this portion of the range, yet they have major implications for the shallow levels of the northern Snake Range metamorphic core complex and faults within major extensional accommodation zones. New detailed 1:12,000 scale geologic field mapping and structural analysis has documented six separate tilt domains along with numerous high- and low-angle, east- and west-dipping-normal faults. Two of the largest and oldest faults are the low-angle, west-directed, Majors Place Detachment (MPD), and the low-angle, east-directed, Schell Peaks Detachment (SPD). These faults along with their hanging wall splays have thinned the exposed rocks underlying the range from 7 km to 2-3 km.

The stratigraphy in the footwall of the SPD and MPD is sub-parallel to faults and is largely unmetamorphosed. The SPD has top-to-the-east displacement and shows a switch in the tilt polarity in the hanging wall from west-tilted in the south to east-tilted in the north. The MPD is a west-directed normal fault, and, based on Ar40/Ar39 analysis of footwall rocks and syntectonic ignimbrites in the hanging wall of the MPD (Gans and Norman, in prep.), was active between 35-40 Ma. The MPD cuts hanging wall structures of the SPD implying the SPD is older than the MPD. The SPD and MPD are cut by a second generation of high-angle normal faults associated with the modern range bounding fault system. The data presented here suggests a three stage model for the structural evolution of the central SCR. 1) Cretaceous shortening created ~NNE trending folds across the eastern Great Basin. 2) Extension, beginning in the Eocene, forming closely spaced normal faults - the SPD and MPD.

The SPD and MPD possibly exploited the limbs of a pre-existing antiform transecting the SCR. The east-directed SPD exploited the east-dipping limb and the west-directed MPD exploited the west-dipping limb. 3) Miocene and younger range bounding normal fault systems at a high angle to bedding and cut the low-angle faults within the range.

Physical Description:
1 online resource (63 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f30v89wt
ISBN:
9781303731518
Catalog System Number:
990041153150203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Bryan Norman
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