Mississippian bioherms of southwestern Missouri and northwestern Arkansas

Author

Arthur R. Troell Jr.

Abstract

"Lenticular bodies of massive limestone, flanked by thin crinoidal beds, crop out in southwestern Missouri and northwestern Arkansas. They are within the St. Joe limestone of the Lower Mississippian.

Strata underlying these bodies typically are down-warped, those on the flanks lapping against, finally passing completely over the limestone core. Dips away from the “reef” are commonly around 5 degrees, but reach as much as 30 degrees. Conglomeratic detritus, originating from the core, occurs in flanking beds at their contact with it.

Thin sections of these masses show no more than 15 per cent of the limestone to consist of fossil remains. These are chiefly encrusting bryozoans and crinoid fragments, with occasional ostracods and brachiopods. The matrix is microspar, its particles ranging from about three to 10 microns in diameter. A minor amount of disseminated clay was observed.

Flanking beds and inter-reef limestones differ in being composed of 50 to 75 per cent fossils; the matrix is more variable and in places coarser than in the core. The clay content, although minor, is apparent along partings.

The lenticular cores, or bioherms, are interpreted as minor elevations caused by entrapment of fine mud by non-calcareous plants in an environment of low energy. Reef-building calcareous organisms are virtually absent. Wave and current action as a formative agent are negated by the presence of fine mud in the bioherm.

Genetic interpretations of certain bioherms from different areas and varying parts of the Paleozoic and Tertiary were discussed and rejected as an explanation for these phenomena"--Introduction, pages 1-2.

Advisor(s)

Spreng, Alfred C., 1923-2012

Committee Member(s)

Frizzell, Don L. (Donald Leslie), 1906-1972
Sutherland, Richard Orlin
Christiansen, Carl R., 1921-1997

Department(s)

Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology

Sponsor(s)

Missouri. Geological Survey

Comments

Page 9, a fold-out map, is included here as supplementary material.

Publisher

Missouri School of Mines and Metallurgy

Publication Date

1960

Pagination

ix, 116 pages

Note about bibliography

Includes bibliographical references (pages 113-115).

Geographic Coverage

Missouri
Arkansas

Time Period

Mississippian

Rights

© 1960 Arthur R. Troell, Jr., All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Bioherms -- MissouriBioherms -- ArkansasCarbonatesGeology, Stratigraphic -- Mississippian

Thesis Number

T 1267

Print OCLC #

5928826

Electronic OCLC #

957264809

Recommended Citation

Troell, Arthur R. Jr., "Mississippian bioherms of southwestern Missouri and northwestern Arkansas" (1960). Masters Theses. 5574.
https://scholarsmine.mst.edu/masters_theses/5574