Alt Title

Ultrapetrography of a miocene chalky limestone, Kingshill Marl, U.S. Virgin Islands

Publication Date

1975

Document Type

Dissertation/Thesis

First Advisor

Frost, Stanley H., 1939-

Degree Name

M.S. (Master of Science)

Department

Department of Geology

LCSH

Petrology--Virgin Islands of the United States--Saint Croix

Abstract

The Kingshill Marl, which crops out on the island of St. Croix in the U. S. Virgin Islands, is a sequence of interbedded chalks and turbidites. The chalks are composed almost entirely of the tests and fragments of tests of planktonic foraminifera and calcareous nannoplankton, and the interbedded turbidites consist of unsorted volcanogenic terrigenous debris and coral fragments, with a marly matrix. The Kingshill Marl was deposited during Miocene time in a shallow trough of fault origin, which trended northeast across the island. To the east and west of the trough, Cretaceous volcanogenic rocks formed highlands that supplied detrital material to the basin of deposition. A modern-day sedimentary analog to the chalky fraction of the Kingshill Marl exists on the island slope off of Canebay, on the northwest shore of St. Croix. The sediment here consists of the tests of planktonic foraminifera and calcareous nannoplankton, but also contains abundant aragonitic pteropods and sponge spicules of opaline silica. The absence of pteropods and sponge spicules in the Kingshill Marl suggests that some process must have acted to dissolve them, and suggests a shallow, warm water environment of deposition for the Kingshill Marl.

Comments

Includes bibliographical references.||Includes illustrations and maps.

Extent

vi, 81 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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