46 D12. Geochronology, Sediments, and Stratigraphy (Posters)

Sunday, 19 March 2023
8:00 AM - 12:00 PM
Grand Ballroom A–D

THE POWER OF PALYNOLOGY: DETERMINATION OF STRATA MISSING AT THE MISSISSPPIAN-PENNSYLVANIAN UNCONFORMITY AND CONSTRAINING THE AGE OF THE DEVONIAN CATSKILL CLASTIC WEDGE IN SOUTHERN MCKEAN AND WESTERN CAMERON COUNTY, PENNSYLVANIA

Paper number: 46-8
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Seven samples from two cored sections were submitted for palynological analysis to determine age and amount of preserved stratigraphy in western Cameron County and southern McKean County, northwestern Pennsylvania to constrain the age of this time-transgressive interval. Palynological results constrain the Catskill Formation in the study area to late Famennian age containing the Apiculiretusispora verrucosa-Vallatisporites hystricosus (VH) palynozone (360.5 to 363.6 mya) and the Retispora lepidophyta (LL-LN) palynozone (358.9 to 360.5 mya).

A sample was taken from the McKean County core approximately 50 feet below the Mississippian-Pennsylvanian unconformity to determine the missing age interval at the unconformity. This sample contained a fossil assemblage of the Retispora lepidophyta palynozone of the late Famennian. This date constrains any preserved Mississippian-aged strata to less than 50 feet, although it is possible that the remaining strata are still latest Devonian.

Samples from within the Catskill Formation are interpreted to be collected from strata representing coastal, primarily non-marine fluvial-swamp margin paleoenvironments. The sample taken from near the Mississippian-Pennsylvania unconformity did not contain marine acritarchs, suggesting the environment of deposition is terrestrial or marginal marine with a high influx of terrestrially sourced sediment, such as the flank of a proximal deltaic facies. Abundant charcoal suggests a possible outflow after a forest fire related to landscape destabilization.

The thermal maturity, estimated from spore color, ranges from 1.0-1.45%Ro and implies a maximum burial temperature of 134°C to 169°C. A thermal gradient of 23°C/km is estimated for southeastern McKean and northern Cameron counties and implies maximum burial depths of 3048-3658m.

Geological Society of America Abstracts with Programs. Vol. 55, No. 2

doi: 10.1130/abs/2023SE-385874

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