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Paper No. 12
Presentation Time: 4:45 PM

STRUCTURAL SETTING OF THE COLES HILL URANIUM PROPERTY, CHATHAM, VA


AYLOR Jr, Joseph G., Virginia Uranium, Inc, 231 Woodlawn Heights, Chatham, VA 24531 and BODNAR, R.J., Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg, VA 24061, jaylor@vauinc.com

The Coles Hill uranium property (CHUP) is located to the west of the Chatham fault in Leatherwood Granite of the western Piedmont of Virginia in the Smith River Allochthon (SRA). The north and south ore bodies are bounded on their east by the Chatham fault, which is the western graben of the Danville Triassic basin. Leatherwood Granite is biotite gneiss, mainly mylonitic gneiss and amphibolite, and capped by a cataclasite, which overlie the oldest Fork Mountain Schist. Since 1978 a significant amount of exploration and development work has been completed.

The ore is generally confined to healed hydrothermal fracture zones in hematitic, chloritized, apatitic and titanium-rich zones in sodium metasomatised and silica depleted rock. Sodium metasomatism is marked by rapakivi granite texture and riebeckite. Hematite is a local indicator of oxidation-reduction associated with deposition of uraninite and pitchblende and the ore is generally considered to be in equilibrium with its daughter products.

The CHUP is hosted in the 440 Ma Leatherwood Granite. Uranium deposition post-dates the granite. The ore bodies are interpreted to be localized along secondary folds on a north plunging fold limb in the north ore body, and on a south plunging fold limb in the south ore body. En echelon, isoclinal folds with fold axes parallel to the Chatham fault occur within the SRA. Secondary, cross-cutting faults and/or fold axes are perpendicular to the Chatham fault. This secondary fold system indicates that mineralization may be present to the south of the south ore body.

The southern ore body has an axial planar strike parallel to the Chatham fault of N30E and dips 35 SE to a depth drilled of 1500 ft. The ore plunges to the south at approximately 45 degrees and has a rake of approximately 20 degrees. The ore zone gradually becomes horizontal as it surfaces in the northern ore body. The northern ore body plunges approximately 20 degrees to the north, indicating an open fold axis crossing the Chatham fault near Coles Hill.

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