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Title: Metamorphosed melange in the central Piedmont of South Carolina

Abstract

The Enoree melange is exposed in the central Piedmont of South Carolina near the boundary between the Piedmont and Carolina terranes. The melange is composed of ultramafic and mafic blocks in a highly deformed matrix of biotite-feldspar-quartz gneiss which has a composition consistent with a felsic-to-intermediate volcanic precursor. The mafic and ultramafic blocks are separated chemically and petrographically into four compositional groups: metagabbro-clinopyroxenite, websterite, orthopyroxenite, and metasomatized (steatitized) orthopyroxenite. Based on their chemistry and mineralogy, the blocks are clearly exotic relative to their metavolcaniclastic( ) matrix and likely originated as parts of a plutonic suite from the basal or forward part of the Carolina arc terrane. If the Piedmont terrane-Carolina terrane boundary is a continent-arc suture, then the Enoree melange probably formed in the accretionary prism at this convergent margin. The matrix gneisses are interpreted as reworked volcanic debris shed by the Carolina arc terrane edifice and accumulated as graywacke in the accretionary deposits. West-vergent structures in the matrix suggest that the melange was emplaced to its present tectonostratigraphic position either during docking of the Carolina terrane or during widespread Alleghenian thrusting.

Authors:
;  [1]
  1. South Carolina Geological Survey, Columbia (USA)
Publication Date:
OSTI Identifier:
7135907
Resource Type:
Journal Article
Journal Name:
Journal of Geology; (USA)
Additional Journal Information:
Journal Volume: 97:5; Journal ID: ISSN 0022-1376
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; GEOLOGIC DEPOSITS; MINERALOGY; SOUTH CAROLINA; BOUNDARY CONDITIONS; DEPOSITION; GEOCHEMISTRY; GEOLOGIC HISTORY; GEOLOGIC MODELS; GEOLOGIC STRUCTURES; METAMORPHISM; MINERALS; ORIGIN; STRATIGRAPHY; VOLCANIC ROCKS; CHEMISTRY; FEDERAL REGION IV; GEOLOGY; IGNEOUS ROCKS; NORTH AMERICA; ROCKS; USA; 580000* - Geosciences

Citation Formats

Mittwede, S K, and Maybin, III, A H. Metamorphosed melange in the central Piedmont of South Carolina. United States: N. p., 1989. Web. doi:10.1086/629340.
Mittwede, S K, & Maybin, III, A H. Metamorphosed melange in the central Piedmont of South Carolina. United States. https://doi.org/10.1086/629340
Mittwede, S K, and Maybin, III, A H. 1989. "Metamorphosed melange in the central Piedmont of South Carolina". United States. https://doi.org/10.1086/629340.
@article{osti_7135907,
title = {Metamorphosed melange in the central Piedmont of South Carolina},
author = {Mittwede, S K and Maybin, III, A H},
abstractNote = {The Enoree melange is exposed in the central Piedmont of South Carolina near the boundary between the Piedmont and Carolina terranes. The melange is composed of ultramafic and mafic blocks in a highly deformed matrix of biotite-feldspar-quartz gneiss which has a composition consistent with a felsic-to-intermediate volcanic precursor. The mafic and ultramafic blocks are separated chemically and petrographically into four compositional groups: metagabbro-clinopyroxenite, websterite, orthopyroxenite, and metasomatized (steatitized) orthopyroxenite. Based on their chemistry and mineralogy, the blocks are clearly exotic relative to their metavolcaniclastic( ) matrix and likely originated as parts of a plutonic suite from the basal or forward part of the Carolina arc terrane. If the Piedmont terrane-Carolina terrane boundary is a continent-arc suture, then the Enoree melange probably formed in the accretionary prism at this convergent margin. The matrix gneisses are interpreted as reworked volcanic debris shed by the Carolina arc terrane edifice and accumulated as graywacke in the accretionary deposits. West-vergent structures in the matrix suggest that the melange was emplaced to its present tectonostratigraphic position either during docking of the Carolina terrane or during widespread Alleghenian thrusting.},
doi = {10.1086/629340},
url = {https://www.osti.gov/biblio/7135907}, journal = {Journal of Geology; (USA)},
issn = {0022-1376},
number = ,
volume = 97:5,
place = {United States},
year = {Fri Sep 01 00:00:00 EDT 1989},
month = {Fri Sep 01 00:00:00 EDT 1989}
}