Integrated exploration techniques for sediment-hosted copper, lower Lisbon Valley, Utah

The Lisbon Valley District, located approximately 40 miles (64 km) southeast of
Moab, Utah, has important occurrences of copper and uranium around the Lisbon
Valley anticline. In 2006, the Lisbon Valleymine (LVMC) was commissioned near the
southeast end of the anticline. Traces of chalcocite were discovered at a shallow depth
in a nearby petroleum well, ultimately leading to the Flying Diamond discovery. The
Lisbon Valley (LV) district lies in the Colorado Plateau region within the section overlying
the Paradox Basin, a Pennsylvanian-age evaporite basin. Copper mineralization
is widespread in the Paradox Basin and is normally associatedwith faulted clastic sediments
near the margins of salt diapirs. There are two phases of alteration in the copper
deposits in the LVarea; pre-mineralization rock preparation, and alteration associated
with the copper event. Four exploration methods utilized for copper in LLV:
drilling, geochemical pathfinders, seismic reflection andCO2-O2 soil gas.Drilling consisted
of core, reverse circulation and single wall “scout” methods. ICP analysis of the
drill samples from the Centennial Deposit indicated elements useful for exploration
were As, Ce, Mo, Pb, Th, and Zn. Moderately elevated Pb and Zn values from drill
holes distal to the main center of LLV mineralization showed a spatial relationship to
elevated copper values and their distribution suggests multiple fluid phases. Seismic
work found a number of shallow faulted clastic horizons. The soil gas study indicates
that some faults identified by the seismic survey may have been conduits for copper
mineralization. The targets identified by the exploration program outside the Flying
Diamond area remains undrilled as LVMC terminated both mining and exploration
efforts in early 2008.