Earth and Planetary Sciences ETDs

Fred Yale

Publication Date

3-27-1964

Abstract

Chemical determinations of calcium and magnesium carbonates, iron, Kjeldahl nitrogen, and sulfate with supplementary petrographic thin-section and insoluble-residue studies and differential thermal analyses were used to study a Virgilian sedimentary cycle in the upper Madera Limestone of New Mexico. In 120 meters of section 4 cycles were recognized; one of these was studied in detail. Cyclic subsidence and subsequent basin filling produced a sequence of gross environmental changes accomplished by organisms in a definite ecological succession. Biologic communities were progressively modified by the changing marine sedimentary cycle. The cycles of the upper Madera Limestone begin with a lower fusulinid claystone, followed by massive limestone that is fusulinid-bearing in the basal part. Upward, the fusulinids are succeeded by a brachiopod-bryozoan fossil assemblage. Overlying the brachiopod-bryozoan assemblage is nodular claystone and the cycle is terminated with nodular red claystone. The various fossil assemblages within the cycle are not simply depth indicators, but have a more consanguineous relationship to the variables of wave base, clastic material, distance from shore, and the phase of the marine sedimentary cycle.

Degree Name

Earth and Planetary Sciences

Level of Degree

Masters

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Roger Yates Anderson

Second Committee Member

Stuart Alvord Northrop

Third Committee Member

Sherman Alexander Wengerd

Language

English

Document Type

Thesis

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