--> Abstract: Cambrian and Precambrian Rifting in Central and Western Kentucky: Evidence from Reflection-Seismic Data, by J. A. Drahovzal; #90950 (1996).

Datapages, Inc.Print this page

Abstract: Cambrian and Precambrian Rifting in Central and Western Kentucky: Evidence from Reflection-Seismic Data

James A. Drahovzal

Newly available reflection-seismic and age-dating data confirm the existence of two and possibly three major, early rifting events in central and western Kentucky that are separated by angular unconformities: Middle Proterozoic, Late Proterozoic(?), and Cambrian. The Middle Proterozoic rifting event is associated with the East Continent Rift Basin (ECRB). This basin is dominated by terrigenous siliciclastic and volcanic rocks and extends from northwestern Ohio to south-central Kentucky. Some of the newly available seismic-reflection data suggest that these rocks extend at least to Union County in western Kentucky. The precise age of the basin is unknown, but based on age-dating data from several wells, it appears to be between 1.02 and 1.5 Ga. Basin fill in the ECRB just est of the Grenville allochthon is more than 5 km thick, thinning westward onto adjacent zones of older silicic and mafic Granite-Rhyolite Province (GRP) rocks, and thickening again in western Kentucky. The subsequent Grenville compressional event thrusted and folded the ECRB and GRP rocks, resulting in a marked angular unconformity of these rocks with younger

AAPG Search and Discovery Article #90950©1996 AAPG GCAGS 46th Annual Meeting, San Antonio, Texas