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Black Shell turbidite, Hatteras Abyssal Plain, western Atlantic Ocean

1979; Geological Society of America; Volume: 90; Issue: 12 Linguagem: Inglês

10.1130/0016-7606(1979)90 2.0.co;2

1943-2674

R. Douglas Elmore, Orrin H. Pilkey, William J. Cleary, H. Allen Curran,

Marine and fisheries research

Research Article| December 01, 1979 Black Shell turbidite, Hatteras Abyssal Plain, western Atlantic Ocean R. DOUGLAS ELMORE; R. DOUGLAS ELMORE 1Department of Geology and Mineralogy, University of Michigan, Ann Arbor, Michigan 48104 Search for other works by this author on: GSW Google Scholar ORRIN H. PILKEY; ORRIN H. PILKEY 2Department of Geology and Marine Laboratory, Duke University, Durham, North Carolina 27708 Search for other works by this author on: GSW Google Scholar WILLIAM J. CLEARY; WILLIAM J. CLEARY 3Department of Earth Sciences, University of North Carolina at Wilmington, Wilmington, North Carolina 28401 Search for other works by this author on: GSW Google Scholar H. ALLEN CURRAN H. ALLEN CURRAN 4Department of Geology, Smith College, Northampton, Massachusetts 01063 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1979) 90 (12): 1165–1176. https://doi.org/10.1130/0016-7606(1979)90 2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. DOUGLAS ELMORE, ORRIN H. PILKEY, WILLIAM J. CLEARY, H. ALLEN CURRAN; Black Shell turbidite, Hatteras Abyssal Plain, western Atlantic Ocean. GSA Bulletin 1979;; 90 (12): 1165–1176. doi: https://doi.org/10.1130/0016-7606(1979)90 2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract An upper Pleistocene turbidite with a volume of at least 1011 m3 (100 km3) has been traced in 35 piston cores over a 44,000 km2 area of the Hatteras Abyssal Plain. Entering the plain from the Hatteras Canyon System, the flow traveled uninterrupted for at least 500 km in a southerly direction and resulted in a tongue-shaped turbidite with a width between 100 and 140 km and a thickness of as much as 400 cm. This turbidite appears to be one of the largest, if not the largest, single turbidite yet to be correlated between deep-sea cores and to be mapped on an abyssal-plain floor.Correlation of the unit is based on grain size, mineralogy, relative thickness, and similarity of sequences in the cores. Because correlation between cores is based largely on sand-layer characteristics, the turbidite cannot be traced beyond the last occurrence of a distinct sand layer in the distal (southerly) direction. The turbidite is characterized by its high percentage (2% to 50%) of blackened mollusk shell fragments, which led to the informal name Black Shell turbidite, and by a coarser grain size than other turbidites in the same cores.The maximum thickness of the turbidite's sand part is in the center of the abyssal-plain basin, whereas maximum thicknesses of lutite and of the total turbidite are displaced east of the center line of the depositional basin. Depending on lateral position in the flow, the sands texturally comprise a wide range of graywackes, and mineralogically they constitute a suite ranging from lithic arkoses to quartzarenites. Sand petrology indicates that the fluvially derived terrigenous fraction came from United States mid-Atlantic coast rivers, whereas molluscan and foraminiferal bioclastic components indicate an initial shallow-shelf origin from the vicinity of Cape Hatteras, North Carolina.It appears that the turbidity current began as a massive shelf-edge slump. Sand came from the shelf edge; mud was picked up on the upper continental slope. The flow apparently evolved from a slump into a high-concentration flow as it moved down-slope. Characteristics in the axial center zone, such as poor sand sorting, high mud content, Bouma AE sequences, and discontinuous vertical grading, suggest deposition from a high-concentration flow. The nature of the characteristics changed (better sorting, more continuous vertical grading, more complete Bouma sequences, and lower mud content) as the flow spread, reflecting deposition from a low-concentration turbidity current. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.