skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evolution of Cambrian-Ordovician carbonate shelf, US Appalachians

Abstract

Newly compiled cross sections and isopach maps of the Cambro-Ordovician continental shelf, U.S. Appalachians shows that thickness and facies trends are controlled by the Adirondack, New Jersey and Virginia and Alabama arches, and depocenters in Tennessee, Pennsylvania and the Rome Trough. Carbonate sedimentation was initiated with drowning of Early Cambrian clastics, deposition of carbonate ramp facies followed by drowning, regional regression and deposition of Early to Middle Cambrian red beds and platform margin rimmed shelf lime sands and reefs. During subsequent regional transgression the Conasauga intrashelf shale basin formed, bounded toward the shelf edge and along depositional strike by Middle to Upper Cambrian oolitic ramp facies and cyclic peritidal carbonates. During Middle Cambrian rifting, the Rome Trough was filled by thick clastics and carbonates. Intrashelf basin filling and regional regression caused progradation of Late Cambrian cyclic carbonates and clastics across the shelf. By this time, the margin had a relief of 2.5 kms. During the Early Ordovician, incipient drowning of the shelf formed subtidal carbonates and bioherms that passed up into cyclic carbonates which grade seaward into lime sands and reefs. Numerous unconformities interrupt this sequence in the Northern Appalachians. Early dolomitization patterns were controlled by regional highs. Subsidence ratesmore » on the margin were low (4 cm/1000 yrs) and typical of a mature passive margin. Shelf sedimentation in the Southern Appalachians ceased with arc-continent collision and development of the Knox unconformity, which dies out into the Pennsylvania depocenter.« less

Authors:
Publication Date:
Research Org.:
Virginia Tech, Blacksburg (USA)
OSTI Identifier:
6198192
Report Number(s):
CONF-8510489-
Journal ID: CODEN: GAAPB
Resource Type:
Conference
Journal Name:
Geol. Soc. Am., Abstr. Programs; (United States)
Additional Journal Information:
Journal Volume: 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CONTINENTAL SHELF; GEOLOGIC HISTORY; STRATIGRAPHY; TECTONICS; USA; APPALACHIAN MOUNTAINS; CAMBRIAN PERIOD; CARBONATE ROCKS; DEPOSITION; ORDOVICIAN PERIOD; SEDIMENTARY BASINS; CONTINENTAL MARGIN; GEOLOGIC AGES; GEOLOGIC STRUCTURES; GEOLOGY; MOUNTAINS; NORTH AMERICA; PALEOZOIC ERA; ROCKS; SEDIMENTARY ROCKS; 580201* - Geophysics- Seismology & Tectonics- (1980-1989); 580100 - Geology & Hydrology- (-1989)

Citation Formats

Read, J F. Evolution of Cambrian-Ordovician carbonate shelf, US Appalachians. United States: N. p., 1985. Web.
Read, J F. Evolution of Cambrian-Ordovician carbonate shelf, US Appalachians. United States.
Read, J F. Tue . "Evolution of Cambrian-Ordovician carbonate shelf, US Appalachians". United States.
@article{osti_6198192,
title = {Evolution of Cambrian-Ordovician carbonate shelf, US Appalachians},
author = {Read, J F},
abstractNote = {Newly compiled cross sections and isopach maps of the Cambro-Ordovician continental shelf, U.S. Appalachians shows that thickness and facies trends are controlled by the Adirondack, New Jersey and Virginia and Alabama arches, and depocenters in Tennessee, Pennsylvania and the Rome Trough. Carbonate sedimentation was initiated with drowning of Early Cambrian clastics, deposition of carbonate ramp facies followed by drowning, regional regression and deposition of Early to Middle Cambrian red beds and platform margin rimmed shelf lime sands and reefs. During subsequent regional transgression the Conasauga intrashelf shale basin formed, bounded toward the shelf edge and along depositional strike by Middle to Upper Cambrian oolitic ramp facies and cyclic peritidal carbonates. During Middle Cambrian rifting, the Rome Trough was filled by thick clastics and carbonates. Intrashelf basin filling and regional regression caused progradation of Late Cambrian cyclic carbonates and clastics across the shelf. By this time, the margin had a relief of 2.5 kms. During the Early Ordovician, incipient drowning of the shelf formed subtidal carbonates and bioherms that passed up into cyclic carbonates which grade seaward into lime sands and reefs. Numerous unconformities interrupt this sequence in the Northern Appalachians. Early dolomitization patterns were controlled by regional highs. Subsidence rates on the margin were low (4 cm/1000 yrs) and typical of a mature passive margin. Shelf sedimentation in the Southern Appalachians ceased with arc-continent collision and development of the Knox unconformity, which dies out into the Pennsylvania depocenter.},
doi = {},
url = {https://www.osti.gov/biblio/6198192}, journal = {Geol. Soc. Am., Abstr. Programs; (United States)},
number = ,
volume = 17,
place = {United States},
year = {1985},
month = {1}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: