Document Type

Thesis

Abstract

The Chatham Fault is the normal border fault of the Danville basin in south central Virginia. The Danville basin is a Mesozoic rift basins in eastern North America formed by continental extension as Pangaea broke apart and the Atlantic Ocean formed. The Danville basin is a half-graben structure bounded to the west by the Chatham Fault Zone. Danville basin strata are tilted with increasing dips toward the Chatham Fault suggesting syndepositional faulting. Strata of the basin include sandstone, shale, and conglomerates interpreted as having been deposited in lacustrine, swamp and fluvial environments. We examined drill core provided by the Virginia Museum of Natural History and Virginia Uranium Incorporated to develop a model of the Chatham Fault’s geometry in the subsurface and define the thickness of the fault’s damage zone. On a very small scale relative to the entire fault, we interpret the Chatham Fault Zone as an amalgam of closely related smaller faults that together develop a main fault core. Chatham fault dips were found to be much lower than previously reported and generally accepted estimates for this and other Mesozoic rift basins. It is interpreted that either the Chatham fault exists at a lower angle than previously thought or, perhaps, the heterogeneous nature of our results is the product of complication by irregularly accumulated fault rocks and/or cross faults which have disrupted the original fault slip surface. The two primary implications of this research are that (1) a lower angle border fault implies a much larger paleobasin of greater lateral extent than previously thought and that (2) potential cross faults could lend credence to a model for uranium mineralization at Coles Hill based on the transport of hydrothermal fluids through fault pathways.

Date Awarded

2014

Department

Geology

Download

Share Feedback

Share

COinS