Kinematic analysis of a possible suture in the southern Appalachians, northwestern North Carolina
- Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Geology
The contact between Grenville-age basement and the Ashe Metamorphic Suite juxtaposes rocks of the Laurentian continent with rocks of apparent oceanic affinities. The occurrence of ultramafic rocks and recently discovered eclogite along the base of the Ashe Metamorphic Suite suggests the possibility that this contact is a suture. Previous workers have demonstrated that the basement/Ashe Metamorphic suite contact is a northwest-directed thrust fault north of the Grandfather Mountain window. Recent maps published by the North Carolina Geological survey show the contact as a folded thrust fault south of the Grandfather Mountain window. The authors detailed kinematic analyses show that the basement/Ashe Metamorphic Suite contact is not a folded thrust surface; instead, they have identified two distinct northeast-striking fault contacts, one showing strike-slip and the other showing dip-slip motion. Kinematic indicators (asymmetric porphyroclasts, shear bands, mica fish, and S-C fabrics) from mylonites along a portion of the basement/Ashe Metamorphic suite contact from Bakersville to Barnardsville, NC demonstrate dextral strike-slip movement on the eastern fault. Preliminary structural analyses of mylonites on the western fault indicate top-to-the-southeast dip-slip movement. The minerals in these mylonites are partially to totally annealed unlike mylonites from the greenschist facies shear zones along the basement/Ashe Metamorphic Suite contact north of the Grandfather Mountain window.
- OSTI ID:
- 6887451
- Report Number(s):
- CONF-9404221-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 26:4; Conference: 43. annual meeting of the Southeastern Section of the Geological Society of America, Blacksburg, VA (United States), 7-8 Apr 1994; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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