Preliminary structural assessment of the central Flowers 7. 5 minute quadrangle, eastern slate belt, North Carolina
- Univ. of North Carolina, Wilmington, NC (United States). Dept. of Earth Sciences
Eastern slate belt lithologies in the central Flowers quadrangle consist of metavolcanic and metasedimentary rocks. Very fine-grained quartz-white mica phyllite containing narrow, discontinuous layers of thinly laminated chlorite-rich rock and fine-grained, thinly layered, feldspar crystal felsic metatuff comprise the dominant, mappable units consistent across the quadrangle. An increase in grain size accompanied by a replacement of chlorite-rich lithologies with biotite [+-] garnet assemblages suggest metamorphic grade increases towards the western half of the quadrangle (quartz-muscovite schist and biotite-quartz-muscovite-feldspar gneiss). An early, northeast-trending foliation (050[degree] to 060[degree]) dipping moderately to steeply southeast persists across the quadrangle and is axial planar to tight to isoclinal, recumbent to moderately inclined folds. Later non-coaxial folding produced steeply plunging, northerly trending (000[degree] to 020[degree]), open, asymmetric structures verging towards the east/southeast. Shear zones formed locally along the axial trend of these later folds and produced protomylonitic to mylonitic ( ) fabrics. Map patterns and cross-sectional interpretations are best explained by modification of zig-zag fold interference patterns. Thin section examination reveals garnets growing across the early axial planar foliation. The observed increase in metamorphic grade across the quadrangle matches the regional Alleghanian prograde event and constrains relative timing of observed deformational fabrics. Noticeably absent are regional, late-stage upright folds.
- OSTI ID:
- 7060052
- 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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