"The Maquoketa Formation (Upper Ordovician-Cincinnatian Series) has been extensively studied for over one hundred years, but a petrographic study of its cyclic lithologies has been neglected. The following six distinct Maquoketa lithologies have been recognized in this study in Pike County, Missouri: 1) phosphatic biosparite, 2) phosphorite, 3) micrite-microsparite, 4) dolomitic shale, 5) dolomitic marlstone, and 6) dolomitic quartz siltstone. Three cycle types are present in the Maquoketa. They are expressed as thin beds (1-20 inches) of alternating micrite-shale, micrite-marlstone, and shale-siltstone. Contacts between different lithologies are sharp, indicating a primary sedimentological origin for the cycles. Precisely what mechanism was responsible for these rapid and repetitive changes in sedimentation is undetermined. All Maquoketa sediments have experienced extensive diagenesis, the most widespread of which were dolomitization, neomorphism of calcium carbonate and formation of syngenetic pyrite. Minor development of authigenic silica, fluorite, and sphalerite were found in selected examples. The formation of sedimentary boudinages, cone-in-cone structures, and minor intrastratal folds is interpreted as having taken place in some micritic sediments before consolidation was completed"--Abstract, page ii.
Spreng, Alfred C., 1923-2012
Grant, S. Kerry
Geosciences and Geological and Petroleum Engineering
M.S. in Geology
V. H. McNutt Memorial Foundation
University of Missouri--Rolla
xi, 220 pages
Maquoketa Group (Mo.)
© 1970 Edwin Carl Kettenbrink, Jr., All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Geology -- Missouri
Geology, Stratigraphic -- Ordovician
Petrology -- Missouri
Diagenesis -- Missouri
Print OCLC #
Electronic OCLC #
Link to Catalog Recordhttp://laurel.lso.missouri.edu/record=b1066590~S5
Kettenbrink, Edwin Carl Jr., "Petrology and diagenesis of the cyclic Maquoketa Formation (Upper Ordovician) Pike County, Missouri" (1970). Masters Theses. 5514.