Provenance versus depositional setting as influences on sandstone composition: An example from the Proterozoic to basal Cambrian of the southern Appalachians
- Kutztown Univ., PA (United States)
- Univ. of Kentucky, Lexington, KY (United States). Kentucky Geological Survey
- Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Science
Tectonic setting is recognized as an influence on sandstone composition; interpretation of sandstone petrology in transitional tectonic settings is more problematic. Such data sets are not easily interpreted based on visual inspections of tectonic discrimination plots. By employing factor analysis, the understanding of the relative effects of provenance and depositional setting can be improved. This study examines sandstone compositional variation within the lower Chilhowee Group which records the rift-to-drift transition of the Laurentian-Iapetus margin. Crossplots for each data subset were constructed reflecting position with respect to the fluvial-marine transition, as independently discerned from sedimentological criteria, and distance along structural strike. Variation in the composition of medium-grained sandstones of the basal Chilhowee of TN, NC, and VA primarily reflects the composition of the source rock. Examination and comparison of petrology and sedimentologic data from the TN embayment and the VA promontory allow inferences to be made regarding paleogeography: source rocks in the TN embayment were dominantly composed of sedimentary rocks with minor contribution of granite-gneiss material and comprised a low-relief terrain; source rocks in the VA promontory were mainly composed of highly variable volcanic and metamorphic rocks and consisted of a higher-relief terrain; the boundary between these two paleogeographic areas may be a fundamental structural boundary. Visual examination of data points from above and below the fluvial-marine transition within a particular stratigraphic section, shows some separation suggesting that reworking modified the primary composition of the sands, but the original provenance signature is still discernable. This study demonstrates the utility of applying numerical analysis to petrologic suites in order to determine the effects of provenance and depositional setting on the composition of ancient sandstone suites.
- OSTI ID:
- 5931873
- Report Number(s):
- CONF-921058-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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