Falls Lake melange, a polydeformed accretionary complex in the North Carolina piedmont

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6194626

Horton, Jr, J W; Blake, D E; Wylie, Jr, A S; Stoddard, E F

The Falls Lake melange in the eastern Piedmont of North Carolina is composed of mafic and ultramafic blocks and pods of diverse shapes and sizes, from about 1 cm to 7 km in length, dispersed without stratigraphic continuity in a matrix of pelitic schist and metagraywacke. The melange lies between the Carolina slate belt on the west and the Raleigh belt on the east. This terrane has been mapped in detail from near Wilton in Granville County, southward for about 40 km to west Raleigh in Wake County. Preliminary petrologic and geochemical data suggest an oceanic crustal origin for the mafic and ultramafic inclusions. Although the lenticular shapes of most fragments are attributable to ductile deformation, a few more equant fragments that are clearly overprinted by the earliest recognized matrix schistosity have round to angular shapes resembling sedimentary clasts. These observations suggest formation by a combination of sedimentary and tectonic processes, perhaps in the accretionary wedge of a convergent plate margin. The Falls Lake melange and the overlying late Proterozoic to Early Cambrian volcanic-arc terrane of the accreted Carolina slate belt were thrust upon a probably continental terrane of the Raleigh belt before overprinting by late Paleozoic folding and metamorphism. The melange and its folded basal decollement are truncated on the east by a later fault of the Nutbush Creek system and have not been found east of this fault.

• Research Organization: Geological Survey, Reston, VA (USA)
• OSTI ID: 6194626
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
INCLUSIONS
CHEMICAL COMPOSITION
NORTH CAROLINA
PLATE TECTONICS
SCHISTS
PETROGENESIS
PETROLOGY
AMPHIBOLITES
GABBROS
GEOCHEMISTRY
GEOLOGIC FAULTS
GEOLOGIC HISTORY
METAMORPHISM
OCEANIC CRUST
CHEMISTRY
EARTH CRUST
FEDERAL REGION IV
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
IGNEOUS ROCKS
METAMORPHIC ROCKS
NORTH AMERICA
PLUTONIC ROCKS
ROCKS
TECTONICS
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