Masters Theses


Chen Zhao


"The Ozark Plateau of south-central Missouri is underlain by Ordovician to Pennsylvanian carbonate and clastic strata. Enigmatic, presumably Pennsylvanian 'filled sink' structures are common on the Ozark Plateau and remain a source of controversy. We present results for U-Pb ages of detrital zircons for 13 samples from the OP. We use U-Pb ages from other Paleozoic clastics and 'filled sinks' on the OP, to suggest: 1) FSS record a period of Middle Ordovician erosion and sedimentation and 2) document significant shifts in sediment provenance that reflect regional tectonic events affecting the North American Craton.

The KDE plots of normalized detrital zircon ages indicate two major changes in the source of detrital zircons for Paleozoic clastics on the Ozark Plateau: (1) the provenance shifted from local the St. Francois Mountain to the Archean Province in the Late Cambrian-Early Ordovician. (2) In Mississippian through the Pennsylvanian time the source shifted from the Archean Province to the central/southern Appalachian Province, with variable contributions from the Grenville Province.

The similarity of the KDE of detrital zircon U-Pb age plots, combined with the MDS analyses, of samples from 'Pennsylvanian FSS' and Ordovician sandstones indicates that these filled sink structures have a higher probability of being coeval with Ordovician clastic sediments. This is consistent with field relationships where the 'Cave Hill' sandstone is correlative to the Ordovician Everton Formation. We suggest that many of these 'sink structures' formed during the sub-Tippecanoe regression and were 'filled' (e.g., Cave Hill) with clastics during the Tippecanoe transgression"--Abstract, page iii.


Hogan, John Patrick

Committee Member(s)

Obrist-Farner, Jonathan
Chapman, Alan D.


Geosciences and Geological and Petroleum Engineering

Degree Name

M.S. in Geology and Geophysics


Missouri University of Science and Technology

Publication Date

Summer 2019


viii, 63 pages

Note about bibliography

Includes bibliographic references (pages 56-62).

Geographic Coverage

Ozark Mountains

Time Period

Paleozoic; Cambrian


© 2019 Chen Zhao, All rights reserved.

Document Type

Thesis - Open Access

File Type




Thesis Number

T 11732

Electronic OCLC #