A Stratigraphic Framework for Late Cambrian-Early Ordovician Carbonate Slope to Basinal Sediments in Tybo Canyon, Hot Creek Range, Nevada
Abstract
The Cambro-Ordovician Hales Limestone in the Hot Creek Range, Nevada records a carbonate slope to toe-of-slope environment. Gigapan™ photomosaics, measured sections, and thin sections of the outcrops help to identify locations, geometries, and continuity of gravity flow deposits, the primary depositional features in the Hales Limestone. The facies identified in the Hales Limestone are: (1a) clast- and matrix-supported conglomerate-breccia beds, (1b) packstone-grainstone beds, (2) alternating thin, planar calcisiltstone and carbonate mudstone beds, (3) wavy, rippled, and cross-bedded calcisiltstone beds with carbonate mudstone, (4) thin, planar carbonate mudstone, and (5) slumped and folded beds of interbedded carbonate mudstone and calcisiltstone. Where facies 1a has a calcisiltstone matrix, it is interpreted to be a turbidite deposit; where it has a carbonate mudstone matrix, it is interpreted as a debris flow deposit. Facies lb is interpreted to be grain flow deposits. Facies 2-5 are interpreted to record interbedded distal turbidites (calcisiltstone) and background, pelagic carbonate mudstone.
This study focuses on the gravity flow deposits (turbidite and debris flow deposits) in the Hales Limestone. The 80% of gravity flow deposits that are continuous across the outcrop formed as strike-continuous aprons, and the 20% of gravity flow deposits that are not continuous across the outcrop formed as individual depositional lobes. Approximately 85% of these gravity flow deposits were formed by turbidity flows, and 15% were formed by debris flows. The majority of the gravity flow deposits are located in the lower portion of the Hales Limestone.
Subject
geologycarbonates
Cambrian
Ordovician
limestone
Gigapan
debris flows
turbidites
gravity flows
Nevada
Citation
Marek, Sandra (2015). A Stratigraphic Framework for Late Cambrian-Early Ordovician Carbonate Slope to Basinal Sediments in Tybo Canyon, Hot Creek Range, Nevada. Master's thesis, Texas A & M University. Available electronically from https : / /hdl .handle .net /1969 .1 /155578.