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Sedimentology, Biostratigraphy, Chemostratigraphy, and Sequence Stratigraphy of Middle Ordovician Strata, Inner Mongolia, China

by Hakim, Anne Josephine

Abstract

Despite superb exposure of the Ordovician strata in the region, and detailed knowledge of the eastern and northeastern margins, the western margin of the North China Block (NCB) lacks an integrated study of sedimentology, biostratigraphy, and chemostratigraphy. This study presents such information, elucidating the depositional history and sequence stratigraphic framework of Middle Ordovician strata in Inner Mongolia, China. Two sections of the Middle Ordovician Kelimoli Formation contain the positive Middle-Darriwilian Carbon Isotope Excursion (MDICE), the first recorded evidence of MDICE in the region. Additionally, biostratigraphic data and previous research in the area allow for the proposal of a sequence stratigraphic framework for the NCB. Specifically, the disconformity at the base of the lowest Middle Ordovician Sandaokan Formation contains a sequence boundary between two megasequences, megasequences 1 and 2, in the lowermost Paleozoic (Myrow et al, in press; Meng et al., 1997). The Sandaokan, Zhuozhishan, and Kelimoli formations represent the first, second, and third sequences of megasequence 2, respectively. The Kelimoli Formation is overlain by a disconformity, which likely corresponds with the upper boundary of this megasequence and with globally widespread nondeposition according to biostratigraphic and chemostratigraphic correlation (Schmitz et al., 2010). This hypothesized sequence stratigraphic framework will be tested in the future with high-resolution biostratigraphic and chemostratigrpahic analysis of the Zhuozhishan Formation.

Note

The author has given permission for this work to be deposited in the Digital Archive of Colorado College.

Colorado College Honor Code upheld.

Includes bibliographical references.

Administrative Notes

The author has given permission for this work to be deposited in the Digital Archive of Colorado College.

Colorado College Honor Code upheld.

Copyright
Copyright restrictions apply.
Publisher
Colorado College
PID
coccc:11214
Digital Origin
born digital
Extent
83 pages : illustrations, map(s)
Thesis
Senior Thesis -- Colorado College
Thesis Advisor
Myrow, Paul
Department/Program
Geology
Degree Name
Bachelor of Arts
Degree Type
bachelor
Degree Grantor
Colorado College
Date Issued
2015-05