4 Structural Geology and Tectonics (Posters)

Thursday, 5 April 2001
8:00 AM - 12:00 PM

GEOLOGY OF THE TAYLORS 7.5-MINUTE QUADRANGLE, INNER PIEDMONT, GREENVILLE COUNTY, SC

Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

New field studies are reevaluating the regional structural relations of the Paris Mountain thrust sheet in the Inner Piedmont. Taylors 7.5-minute quadrangle (TQ), Greenville County, South Carolina, was mapped in detail to begin this study. TQ is located east of Paris Mountain (Paris Mountain thrust sheet) and south of the Seneca fault (Six Mile thrust sheet). Major rock types within TQ are: fine- to coarse-crystalline biotite gneiss with interlayered amphibolite; mica schist with interlayered fine-crystalline biotite gneiss and sillimanite schist; and granitoid. These rocks are correlated with the Tallulah Falls Formation and crop out as distinct packages. In the northern third of TQ, the biotite gneiss package occurs extensively. The middle third is dominantly mica schist. In the southern third, mica schist is intruded by abundant granitoid; coarse-crystalline biotite gneiss also crops out.

Mapping suggests the following deformational history: early recumbent folding; intrusion of granitoid; polyphase folding; and imbricate thrust faulting. Evidence for early recumbent folding is found in the biotite gneiss and mica schist packages. Granitoid intruded the mica schist package prior to both rock packages being deformed into a northeast-trending synform. This synform was subsequently refolded by a north-trending antiform. Northwest-striking imbricate thrusts juxtapose pods of granitoid and mica schist, and this faulting is presently interpreted to be younger than the polyphase folding.

The imbricate thrusts in the western half of TQ are similar to thrusts mapped on Paris Mountain by Niewendorp and others (1997). The macroscopic folds in the eastern half of TQ are similar to those found in adjacent Greer quadrangle (Maybin, 1998). At present, no continuous structure has been identified in the northern third of TQ where a thrust has been proposed to separate the Paris Mountain and Six Mile thrust sheets (Nelson and others, 1998).