Conodont paleoecology of Lower Triassic Thaynes Formation

Conference · Tue Mar 01 00:00:00 EST 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6326896

Carr, T R

The Lower Triassic (Smithian) Thaynes Formation represents a broad spectrum of paleoenvironments. Samples arranged along a generalized depth-salinity environmental gradient from tidal flats to a relatively deep, commonly dysaerobic, basin yielded a conodont fauna of 30 form elements. Association and similarity analysis were used to group the conodont elements into eight conodont entities, reflecting both biologic association (multielement apparatuses) and ecologic association (biofacies). Simple chi-square tests and discriminant analyses, using the eight conodont entities, and indicate presence of three distinctive conodont biofacies related to the generalized environmental gradient. The restricted inner shelf biotope was characterized by a conodont fauna dominated by Parachirognathus. The outer shelf biotope was distinguished by a diverse conodont fauna including the distinctive form Furnishius. The biotope farthest offshore consists of a low diversity conodont fauna composed primarily of species of Neogondolella. Some early Triassic conodonts such as Neospathodus and Ellisonia triassica are ubiquitous, and provide the foundation for a inter-basinal conodont zonation. Early Triassic conodont biotopes can be arranged along a generalized environmental gradient that probably reflects changes in hydrographic factors (e.g., salinity, temperature, and energy) which affected the distribution of conodonts.

• Research Organization: ARCO Oil and Gas Co., Dallas, TX
• OSTI ID: 6326896
• 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

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
FOSSILS
CORRELATIONS
RESERVOIR ROCK
DEPOSITION
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
PETROLEUM DEPOSITS
TRIASSIC PERIOD
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MESOZOIC ERA
MINERAL RESOURCES
RESOURCES
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
580100 - Geology & Hydrology- (-1989)