Publication Date

1985

Document Type

Dissertation/Thesis

First Advisor

Weiss, Malcolm P. (Malcolm Pickett), 1921-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Geology

LCSH

Diagenesis; Geology; Stratigraphic--Oligocene; Carbonate rocks; Geology--Antigua

Abstract

Carbon and oxygen stable isotopes of Antigua's limestones and calcareous tuffs were studied to interpret the diagenetic histories of these rocks. The older rocks (the Basal Volcanic Suite and Central Plain Group) were found to be isotopically distinct from the younger rocks (the Antigua Formation and Holocene limestones). The limestones and calcareous tuffs of the Basal Volcanic Suite (BVS) and Central Plain Group (CPG) are more depleted in ¹⁸O and ¹³C than their counterparts in the Antigua Formation (AF) and Holocene limestones (Hl). For example, the average δ ¹⁸O (PDB) value in the BVS and CPG is -9.0 °/oo ( δ ¹⁸O SMOW = +21.6 °/oo) whereas the average δ ¹⁸O (PDB) value in the AF and Hl is -3.7 °/oo ( δ ¹⁸O SMOW = +27.0 °/oo). The average δ ¹⁸C (PDB) value in the BVS and CPG is -4.9 °/oo and the average δ ¹⁸C (PDB) value in the AF and Hl is -1.5 °/oo. The stable isotope data, petrography, and field relationships suggest the rocks from the BVS and CPG were influenced mainly by hydrothermal fluids and elevated temperatures whereas the rocks from the AF and HI were subjected to freshwater diagenesis.

Comments

Bibliography: pages 68-72.

Extent

vii, 105 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.

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