Identifier

etd-04102012-103841

Degree

Master of Science (MS)

Department

Geology and Geophysics

Document Type

Thesis

Abstract

The Eocene-Oligocene (E-O) transition is a key interval in geological history because it marks a major change in Earth’s climate and because these strata are also popular oil targets in the Gulf Coast. E-O sequences in Alabama are stratigraphically complex. The St. Stephens Quarry (SSQ) in Alabama is one of the few accessible quarries along the Gulf Coast where the E-O boundary is visible in outcrop. Despite the abundance of research projects conducted in the SSQ, many controversies still surround the E-O boundary placement and correlation to the Global Stratotype in the Massignano section in Italy that is based on the extinction of the Hantkeninidae family. The lack of Hantkenina sp. (Miller et. al., 2008) in a core from near the SSQ and the stratigraphy there contribute to the controversy in boundary placement. To supplement the rarity of foraminifera biomarkers in the section, I present the results of a high-resolution palynological study of the St. Stephens Quarry in Alabama, to help better constrain the boundary placement and associated environmental changes. The new data provide 1) an alternate biostratigraphic zonation and locate the E-O boundary based on organic-walled microfossils to increase biostratigraphic control in the Gulf Coast region, 2) a way to supplement and assist biosteering when foraminifera are not present, and 3) new environmental data (sea-surface conditions and climate) across the boundary. By comparing SSQs palynomorph assemblages to worldwide stratigraphic charts we have established that the E-O boundary occurs within the transition between the Shubuta marl and the Bumpnose limestone (between 3.60- 3.65m depth).

Date

2012

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Warny, Sophie

DOI

10.31390/gradschool_theses.3330

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