New model of succession of Middle and Late Pennsylvanian fossil communities in north Texas, Mid-Continent, and Appalachians with implications on black shale controversy
A new model for the succession of Pennsylvanian fossil communities, preserved in cyclothems, is proposed on the basis of more than 200 fossil localities in the Mid-Continent, Appalachians, and north Texas. Early models for Mid-Continent cyclothems placed the black shales in shallow water, with maximum transgression at the fusulinid-bearing zone in the overlying limestone. The most recent model proposed that the black phosphatic shales, which commonly occur between two subtidal carbonates, are widespread and laterally continuous over great distances and represent maximum transgression. The black phosphatic shales contain: ammonoids; inarticulate brachiopods; radiolarians; conularids; shark material and abundant and diverse conodonts. The black shales grade vertically and laterally into dark gray-black shales which contain many of the same pelagic and epipelagic forms found in the phosphatic black shales. This facies contains the deepest water benthic community. Most of these forms are immature, pyritized, and generally are preserved as molds. The dark gray-black facies grades into a medium gray shale facies which contains a mature molluscan fauna. The medium gray shale grades into a lighter gray facies, which is dominated by brachiopods, crinoids, and corals, with occasional bivalves and gastropods. (These facies are interpreted as being a moderate to shallow depth shelf community). The brachiopid-crinoid community is succeeded by shallow water communities which may have occupied shoreline, lagoonal, bay, interdeltaic, or shallow prodeltaic environments.
- Research Organization:
- MAPCO Production Co., Tulsa, OK
- OSTI ID:
- 6156010
- Report Number(s):
- CONF-8304200-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 67:3; Conference: Annual AAPG/SEPM/EMD/DPA convention, Dallas, TX, USA, 17 Apr 1983
- Country of Publication:
- United States
- Language:
- English
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Ostracode distribution in Late Pennsylvanian Finis Shale cyclothem
Biostratigraphic correlation of eustatic cyclothems (basic Pennsylvanian sequence units) from Midcontinent to Texas and Illinois
Related Subjects
BLACK SHALES
GEOLOGIC HISTORY
GEOLOGIC MODELS
APPALACHIA
DEPOSITION
FEDERAL REGION VII
FOSSILS
ORIGIN
PENNSYLVANIAN PERIOD
SOURCE ROCKS
TEXAS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
ENERGY SOURCES
FEDERAL REGION VI
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC FORMATIONS
MATERIALS
NORTH AMERICA
OIL SHALES
PALEOZOIC ERA
USA
040201* - Oil Shales & Tar Sands- Site Geology- (-1989)