Date of Award

12-1982

Degree Name

Master of Science

Department

Geosciences

First Advisor

Dr. William B. Harrison III

Second Advisor

Dr. W. Thomas Straw

Third Advisor

Dr. Richard Passero

Access Setting

Masters Thesis-Open Access

Abstract

Pennsylvanian outcrops along the Michigan Basin's southern/margin are composed of fluvial-deltaic and marine shelf sediments. Constructive deltaic facies include point-bar sandstones displaying erosional bases, channel lag, and upward decreasing grain size and sedimentary structures. Cross-stratification data indicate a unimodal, highly variant, northward-trending, paleocurrent pattern that deviates from regional paleoslope. Point-bar sandstones record delta plain deposition by meandering distributary channels. Channel margin facies include Lingula-bearing, interdistributary bay shales; overlain gradationally by laminated, flaser-bedded and rooted marsh shales and siltstones; and subbituminous swamp coal. Bay-fill facies are interrupted by lens-shaped, quartz-poor, fine-grained, crevasse-- splay sandstones.

Delta destructive facies--quartz -rich bioturbated sandstone-- suggest delta lobe abandonment and landward reworking of delta front sands over the subsiding deltaic plain. Subsidence resulted in deposition of thin, marine shales and overlying micrites which contain diverse marine fauna and <20% terrigenous clastic detritus.

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Geology Commons

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