Masters Theses
Date of Award
12-1988
Degree Type
Thesis
Degree Name
Master of Science
Major
Geology
Major Professor
Steven G. Driese
Committee Members
RaNaye Dreier, Robert Hatcher, Kenneth Walker
Abstract
The Rome Formation (Lower Cambrian) of East Tennessee is usually considered a terrigenous clastic sequence. Although dominated by siltstone, sandstone, and shale Ethologies, the Rome also contains a significant dolostone component. Thus, the Rome in actuality is a mixed siliciclastic and carbonate sequence. This study first constructs a detailed stratigraphy, then, defines lithofacies, interprets their paleoenvironments, and culminates with the presentation of a facies model for the Rome. The study area is located on the U.S. Department of Energy Reservation in Oak Ridge, Tennessee along a twelve kilometer segment of Haw Ridge, which contains Rome Formation exposed along strike within the Copper Creek thrust sheet.
The stratigraphy of the Rome presents a complex problem. As decollement unit to Valley and Ridge thrusting, an already complicated Rome stratigraphy is further confused by structure. Rome structure and stratigraphy are inseparably interrelated. Within the study area, the Rome consists of three structural blocks separated by two tear faults. Two blocks contain reasonably uninterrupted stratigraphic sections, and the other block contains two major imbricate thrusts, duplicating Rome stratigraphy within the block. After restoration, the original undeformed stratigraphy of the Rome has a mosaic pattern and correlates only on a gross scale.
Using the stratigraphy, seven lithofacies are defined in the field area. The first three facies (TB ss/sh, V sh, and B slts/sh/ss) represent pure terrigenous clastic end-members which were deposited in a broad, expansive tidal flat environment that was frequently inundated by storms. The next two are mixed facies (ss/ds and ds/slts), which represent the gradational boundary along which the pure terrigenous clastic facies and pure carbonate facies meet, i.e., "facies" type mixing (Mount, 1984). The final two facies are pure carbonate end members (M ds and Lam ds), which were deposited in a quieter water, protected, back platform environment.
The most basic aspect of the fades model presented is that the Rome inherited a "carbonate platform" type basin built up during the deposition of the underlying Shady Dolomite, and the configuration of this basin forced the siliciclastic sediments of the Rome to take on a mosaic, "carbonate-like" stratigraphy.
Approaching the Rome as a terrigenous clastic sequence has neither been successful in developing a coherent stratigraphy nor in creating a regional depositional model for the Rome. A mixed carbonate and siliciclastic approach explains the "uncorrectable" stratigraphy of the Rome and also accounts more easily for the rapid shifts in Rome paleoenvironments. Eventually, interpretation as a mixed siliciclastic and carbonate sequence may lead to the development of a comprehensive regional depositional environment model for the Rome in East Tennessee.
Recommended Citation
McReynolds, Joseph A., "Paleoenvironments and facies relations of the Lower Cambrian Rome Formation along Haw Ridge on the U.S. Department of Energy Reservation, Oak Ridge area in Roane and Anderson counties, Tennessee. " Master's Thesis, University of Tennessee, 1988.
https://trace.tennessee.edu/utk_gradthes/13283
