Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Trupe, C. H. Articles by Hewitt, L. K. Search for Related Content GeoRef GeoRef Citation

The Burnsville fault: Evidence for the timing and kinematics of southern Appalachian Acadian dextral transform tectonics

Charles H. Trupe^,1, Kevin G. Stewart^,2, Mark G. Adams³, Cheryl L. Waters^#,4, Brent V. Miller^,4 and Lauren K. Hewitt^,4

¹ Department of Geology and Geography, Georgia Southern University, Statesboro, Georgia 30460-8149, USA
² Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA
³ Department of Geology, Appalachian State University, Boone, North Carolina 28608, USA, and UNIMIN Corporation, Harris Mining Company Road, Spruce Pine, North Carolina 28777, USA
⁴ Department of Geological Sciences, University of North Carolina, Chapel Hill, North Carolina 27599, USA

There has been a conspicuous absence of documented Acadian structures in the Blue Ridge province of the southern Appalachians even though a growing body of evidence suggests that the middle Paleozoic Acadian orogeny affected the rocks of this region. New mapping along with structural, petrologic, and geochronologic data from western North Carolina show that the contact between the metasedimentary and metavolcanic rocks of the Ashe Metamorphic Suite and the Grenville basement rocks of the western Blue Ridge corresponds to a Devonian high-grade, dextral strike-slip fault zone, the Burnsville fault. Timing of motion on the Burnsville fault is constrained by field relationships, metamorphic fabrics and assemblages, and radiometric ages. A U-Pb zircon crystallization age for a pegmatite sheared by the Burnsville fault shows that the last movement on the fault must be younger than 377 Ma. Previously published ⁴⁰Ar/³⁹Ar cooling ages show that the Burnsville fault must be older than ca. 360 Ma. We have mapped the Burnsville fault for 100 km in northwestern North Carolina. The Gossan Lead fault of northwesternmost North Carolina and southwestern Virginia is the likely continuation of the Burnsville fault to the northeast. Southwest of Asheville, North Carolina, the Burnsville fault may connect to the Devonian Dahlonega shear zone, or may be cut by post-Devonian thrust faults associated with the Alleghanian orogeny. Diachroneity of Acadian clastic wedges, the presence of Silurian-Devonian pull-apart basins, the presence of Devonian high-grade, dextral shearing in the Inner Piedmont, and recent plate reconstructions for the middle Paleozoic, support the interpretation that the late phase of the Acadian orogeny in the southern Appalachians was primarily a dextral transpressional event. The Burnsville fault and the Inner Piedmont formed the boundaries of a dextral transform margin that may have extended the length of the Appalachian orogen. This interpretation requires that models for the Paleozoic tectonics of the Appalachians incorporate major pre-Alleghanian dextral displacement.

Key Words: Structural geology • tectonics • Appalachians • Acadian orogeny • Burnsville fault • strike-slip faults

This article has been cited by other articles:

				J. Hibbard and J. W.F. Waldron Truncation and translation of Appalachian promontories: Mid-Paleozoic strike-slip tectonics and basin initiation Geology, June 1, 2009; 37(6): 487 - 490. [Abstract] [Full Text] [PDF]

				K.M. Clemons and D.P. Moecher Reinterpretation of the Greenbrier fault, Great Smoky Mountains: New petrofabric constraints and implications for southern Appalachian tectonics Geological Society of America Bulletin, June 1, 2009; 121(7-8): 1108 - 1122. [Abstract] [Full Text] [PDF]

				A. J. Merschat and R. D. Hatcher Jr. The Cat Square terrane: Possible Siluro-Devonian remnant ocean basin in the Inner Piedmont, southern Appalachians, USA Geological Society of America Memoirs, January 1, 2007; 200(0): 553 - 565. [Abstract] [Full Text] [PDF]

				A. J. Dennis Cat Square basin, Catskill clastic wedge: Silurian-Devonian orogenic events in the central Appalachians and the crystalline southern Appalachians Geological Society of America Special Papers, January 1, 2007; 433(0): 313 - 329. [Abstract] [Full Text] [PDF]

				B. V. Miller, A. H. Fetter, and K. G. Stewart Plutonism in three orogenic pulses, Eastern Blue Ridge Province, southern Appalachians Geological Society of America Bulletin, January 1, 2006; 118(1-2): 171 - 184. [Abstract] [Full Text] [PDF]