Earth:Brevard Fault

From HandWiki
Brevard Fault Zone cutting through the southeastern United States.
Brevard Fault Zone in its extent from Montgomery, Alabama to the North-Carolina-Virginia border.

The Brevard Fault Zone is a 700-km[1] long and several km-wide thrust fault that extends from the North Carolina-Virginia border, runs through the north metro Atlanta area, and ends near Montgomery, Alabama. It is an important Paleozoic era feature in the uplift of the Appalachian Mountains.[2]

Discovery

Arthur Keith from the United States Geological Survey first identified an exposed segment of the Brevard Fault in 1905,[3] believing it to be a syncline. In 1932, Anna Jonas Stose’s used local petrology to identify the site as a thrust fault.[4] Stose, the first to trace the fault, is also credited with identifying that the rocks in the area must have been formed through deformation,[5] placing the Brevard Fault in a regional perspective.[3] Using modern methods of seismic reflection and high-resolution profiling, geologists have since discovered that the Brevard Fault Zone has undergone both thrust and strike-slip movement.[6]

Geology

The Brevard Fault Zone is a part of a much larger system of faults at the base of the Appalachian thrust sheet[1] that played a key role in uplifting the Appalachian Mountains. The extent of its role remains uncertain because most of the fault is buried beneath Quaternary sediment.[7] Many studies of the fault come from Grandfather Mountain in the Linville Fall Quadrangle,[8] which contains the exposed region that was first discovered by Arthur Keith. This region is only 1-3 km of its 700 km length.[7]

The Brevard Fault experienced multiple phases of deformation and minimal stratigraphic displacement.[3] The Brevard Fault Zone contains diverse lithologies, but it is primarily composed of mylonitic metagraywacke, schist, amphibolite, and gneiss[9] that underwent metamorphism 350-360 million years ago.[1] The Fault Zone is characterized by ductile behavior as indicated by the widespread presence of mylonitic and phyllonitic rocks.[1]

See Also

Geology of Georgia

Geology of North Carolina

Bibliography

References

  1. 1.0 1.1 1.2 1.3  , Wikidata Q59666174
  2.  , Wikidata Q105126340
  3. 3.0 3.1 3.2 Bobyarchick, Andy (1999). "The history of investigation of the Brevard fault zone and evolving concepts in tectonics". Southeastern Geology 38 (3): 223-238. https://www.researchgate.net/publication/286878149_The_history_of_investigation_of_the_Brevard_fault_zone_and_evolving_concepts_in_tectonics. 
  4. Dietrich, R. V. (1974). "Memorial to Anna I. Jonas Stose". https://www.geosociety.org/documents/gsa/memorials/v06/Stose-AIJ.pdf. 
  5. Jonas, Anna Isabel (1932). "Structure of the metamorphic belt of the southern Appalachians" (in en). American Journal of Science s5-24 (141): 228–243. doi:10.2475/ajs.s5-24.141.228. ISSN 0002-9599. https://www.ajsonline.org/content/s5-24/141/228. 
  6. Gore, Pamela J. W.; Witherspoon, William D. (2013). Roadside Geology of Georgia. Missoula, Montana: Mountain Press Publishing Company. pp. 187. ISBN 978-0-87842-602-7. OCLC 872634030. https://www.worldcat.org/oclc/872634030. 
  7. 7.0 7.1 Hatcher, Robert D.; Huebner, Matthew T.; Rehrer, Justin R.; Acker, Louis L.; Fullagar, Paul D.; Liu, Angang; Goad, Patricia Lee (2017). "Geologic and kinematic insights from far-traveled horses in the Brevard fault zone, southern Appalachians" (in en). Linkages and Feedbacks in Orogenic Systems: Geological Society of America Memoir 213: 313-351. doi:10.1130/2017.1213(13). https://pubs.geoscienceworld.orghttps//pubs.geoscienceworld.org/books/book/1863/chapter/11505202/Geologic-and-kinematic-insights-from-far-traveled. 
  8. Reed, Jr., John C. (1964). "Geology of Linville Falls Quadrangle North Carolina". Geological Survey Bulletin 1161-B: B3. https://pubs.usgs.gov/bul/1161b/report.pdf. 
  9. "Mineral Resources Online Spatial Data". https://mrdata.usgs.gov/geology/state/map-us.html#home.