Abstract

The Southwest Davis Zinc Field (SDZF) is among the westernmost MVT districts associated with the Allegheny-Ouachita orogeny in the midcontinent U.S. It consists of a series of small zinc sulfide deposits and associated dolomitization covering an area of ~ 16 km² (6 mi²) adjacent to the Arbuckle Anticline in southern Oklahoma. Mineralization occurs within the Royer Dolomite (Upper Cambrian) and the Butterly Dolomite (Lower Ordovician) of the Arbuckle Group and is associated with faults and breccia bodies that parallel the trend of the anticline. Mining activity in the SDZF was restricted to the early part of the 20^th century.

Ore mineralization consists chiefly of sphalerite and subordinate smithsonite with minor galena, chalcopyrite, and pyrite, as well as supergene alterations of these minerals. Homogenization temperatures (T_h) of fluid inclusions in gangue dolomite cement range from 88° to 101°C and have salinities of 6.5 to 20.9 wt.% NaCl equivalent. Rarer fluid inclusions in sphalerite have an average T_h value of 105°C and average salinity of 19.2 wt.% NaCl equivalent. Gangue dolomite cements have δ¹⁸O values of −6.9 to −9.1‰VPDB and δ¹³C values of −0.2 to −1.1‰VPDB. The ⁸⁷Sr/⁸⁶Sr ratios for these dolomites range from 0.7088 to 0.7105. Mineralization likely occurred from a flow system in which basement-influenced brines entered the host formations through faults and circulated through the brecciated zones. As the ore hydrothermal system waned, the relative importance of local brines within the carbonate section increased and resulted in precipitation of late dolomite cements.