Community structure in nearshore Permian environments

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6196762

Kaesler, R L; Denver, L E

The lower part of the Americus Limestone in the Midcontinent was deposited near shore. Environments ranged from tidal flats to open-marine settings and included lagoons and carbonate shoals. Tabular cryptalgal structures that show subtle morphological variations with environment are the dominant sedimentary feature of the rocks. The fossilized part of benthic marine communities associated with the cyanobacteria comprised attached foraminifera, Spirorbis worms, several species of immature gastropods too small to identify, rare clams of the genus Orthomyalina, and abundant ostracodes. A low-diversity, characteristically near-shore ostracode fauna was extracted from the cryptalgal limestone by crushing the rock and then following standard micropaleontological procedures. The most abundant species are Paraparchites humerosus, Sansabella bolliabormis, Bairdia beedei, and Cavellina nebrascensis, all of which are typical throughout the Midcontinent of rocks deposited in near-shore environments. The distribution and diversity of the ostracode fauna support paleoenvironmental interpretations based on carbonate petrology and the morphology and microstratigraphy of the cryptalgal structures. In general, rocks deposited on the tidal flat have lowest species diversity, whereas the faunas from rocks of the open-marine environment are more diverse. Distributions of ostracodes and morphology of cryptalgal structures were both sufficiently controlled by environment of deposition to permit discrimination of paleoenvironments in cores from the subsurface.

• Research Organization: Univ. of Kansas, Lawrence (USA)
• OSTI ID: 6196762
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
CARBONATE ROCKS
DEPOSITION
FEDERAL REGION VIII
FOSSILS
GEOLOGIC AGES
GEOLOGIC HISTORY
GEOLOGY
LIMESTONE
NORTH AMERICA
PALEONTOLOGY
PALEOZOIC ERA
PERMIAN PERIOD
PETROLOGY
ROCKS
SEDIMENTARY ROCKS
SPECIES DIVERSITY
STRATIGRAPHY
USA