Central Kentucky Mineral District: record SC2104

Region	Central, South Central
States	Kentucky
Mineral systems	Basin brine path
Deposit types	Barite (replacement and bedded) Zinc-lead (MVT and sedex)
Commodities	cadmium calcite copper lead silver
Critical minerals	barite fluorspar zinc
Other minerals	barite cobalt fluorspar gallium germanium indium tin zinc

Information leading to the delineation of this focus area

Basis for focus area	Outline of the Central Kentucky Mineral District.
Identified resources	Historical production of barite, calcite, fluorite, lead, and zinc.
Production	Unknown.
Status	Past mining; exploration for deeper mineral potential in the Cambrian-Ordovician Knox Group has been conducted for several years and has yielded traces of metallic and nonmetallic minerals, although no commercial ore bodies have been discovered.
Estimated resources	Unknown.
Geologic maps	Complete geologic map coverage at 1:24,000 scale by the Kentucky Geological Survey.
Geophysical data	Inadequate aeromagnetic and aeroradiometric data.
Favorable rocks and structures	All veins cut through Ordovician carbonates along fractures and faults.
Deposits	Lexington Quarry vein, Gratz mine (MRDS dep_id: 10106249), Twin Chimney fluorspar mine.
Evidence from mineral occurrences	MRDS.
Geochemical evidence	Veins contain barite, fluorite, calcite, sphalerite, galena, pyrite, chalcopyrite, and marcasite; some secondary carbonates including malachite, smithsonite, witherite, strontianite, and cerussite have also been observed or reported. Barite commonly contains high Sr, and strontianite and celestite is found with barite in some veins.
Geophysical evidence	No data.
Evidence from other sources	Documented mineralization (sphalerite, galena, barite, fluorite). The Lexington Quarry vein deposit was discovered during limestone quarrying and later mined for sphalerite during normal quarrying operations.
Comments	Because the veins occur in carbonate rocks on the flanks of an intercontinental basin with little or no associated igneous activity, and are associated with solution-collapse features, they are considered Mississippi Valley-type deposits (Ohle 1980).
Cover thickness and description	Surface to 200 ft.
Authors	William M. Andrews, Gina Lukoczki.
New data needs	Geochemical analyses, subsurface vein and deposit model.
Geologic mapping and modeling needs	Not required.
Geophysical survey and modeling needs	High resolution geophysical aeromagnetic and aeroradiometric coverage to determine underlying basement control on sedimentary cover mineralization.
Digital elevation data needs	Variable lidar quality; some complete, some planned/funded, some inadequate.