Depositional environments of the Upper Ordovician Sequatchie and Silurian Rockwood formations of upper East Tennessee

Author

James R. Thompson

Date of Award

3-1984

Degree Type

Thesis

Degree Name

Master of Science

Major

Geology

Major Professor

Fred B. Keller

Committee Members

Thomas Broadhead, Robert McLaughlin

Abstract

Exposures of and the Upper Ordovician Sequatchie Silurian Rockwood formations at Lone Mountain approximately 25 kilometers northwest of Knoxville, Tennessee, respec-tively represent the remains of an ancient siliclastic tidal flat environment and an ancient sublittoral shelf environment. Both environments existed along the eastern shoreline of a large epicontinental sea which lay to the west during their deposition.

The presence of sedimentary structures indicative of wave and current action, intermittent subaerial exposure, alternating bedload transport and suspension sedimentation, loading, alternating erosion and deposition, late stage emergent runoff, reversing currents and bioturbation all point to tidal flat environment of deposition for the Sequatchie Formation. composed of four facies: and Nodular Carbonate. facies, deposits of the Sequatchie Formation compare closely to those of modern day "Wadden type" siliclastic tidal flat deposits occurring along the North Sea coasts of Germany and the Netherlands (Reineck, 1967, 1972, 1975; Van Straaten, 1954, 1959). This tidal flat environment was Mudstone; Heterolithic; Siltstone Excepting the latter of these.

Exposures of the overlaying Rockwood Formation contain an abundance of shales interbedded with randomly occurring storm sand layers. This lithology coupled with sequences of amalgamated sandstone and coarsening upward sandstone argues for a shallow sublittoral shelf environment of deposition that was inundated by coastal storms on an irregular but rather frequent basis. The Rockwood depositional environment compares most closely with that of an Oxfordian age sublittoral shelf environment composed of marine sand bar and interbar deposits which existed in Wyoming during the Upper Jurassic (Brenner and Davies, 1973, 1974).

Recommended Citation

Thompson, James R., "Depositional environments of the Upper Ordovician Sequatchie and Silurian Rockwood formations of upper East Tennessee. " Master's Thesis, University of Tennessee, 1984.
https://trace.tennessee.edu/utk_gradthes/14728