Paleomagnetic Analysis of the Scottsville Mesozoic Rift Basin, Virginia PDF Download

Author: Nathan Charles Keithline
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 86

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Book Description
The Scottsville basin forms one of the westernmost Mesozoic rift basins in Virginia. The basin lies ~25 km SW of Charlottesville, VA astride the transition zone between the Eastern Blue Ridge and Western Piedmont geologic provinces. The ~110 km2 basin is a half-graben bounded by a normal fault to the northwest, and unconformably overlies phyllitic rocks of the Piedmont on its southeast margin. Sedimentary rocks in the basin range from boulder conglomerates to sandstone and siltstone red beds and are sourced primarily from the Proterozoic units of the Blue Ridge. NNW striking diabase dikes associated with the Central Atlantic Magmatic Pulse (CAMP) crosscut the sedimentary strata. The purpose of this research was to conduct paleomagnetic analysis on rocks in the basin to better understand the geologic history of the Scottsville basin and the Atlantic rift margin. Paleomagnetic data from conglomerates, siltstones, and diabases sampled across the Scottsville basin indicate post-deposition, post-deformation Middle Jurassic (160-180 Ma) magnetization ages of sedimentary rocks in the basin, contrasted with a primary depositional Late Triassic (210-220 Ma) magnetization age observed in rocks in other proximal rift basins, including the Danville, Taylorsville, and Newark basins. A possible explanation for this later magnetization age is a chemical remagnetization associated with fluid intrusion associated with the late stages of Pangea rifting.