Confirmation of multiple fluid involvement in the Sweetwater MVT district, Tennessee

Conference · Mon Dec 31 23:00:00 EST 1984 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6576578

Gesink, J A; Kesler, S E

Previously reported observations on fluid inclusions in fluorite from the Knox-hosted Sweetwater (SW) F-Ba-Zn MVT district in East Tennessee have shown an inverse correlation between homogenization and final melting temperatures, which was tentatively ascribed to mixing of two solution. In an effort to determine whether this phenomenon was caused by salinity differences alone or variations in the Ca/Na ratio of the fluid, the authors have determined the Ca/Na ratio of the fluid inclusions using the temperature at which the cotectic phase NaCl x 2H/sub 2/O disappears in the ternary system H/sub 2/O-NaCl-CaCl/sub 2/. Data on 30 inclusions from both early and late stage fluorite show no correlation between CaCl/sub 2//CaCl/sub 2/ + NaCl ratios and salinity over a total salinity range of 9 to 21 equivalent wt % NaCl, further suggesting that the inverse correlation represents mixing of a highly saline brine with a more dilute, but warmer brine of similar Ca/Na ratio. The observations can be explained by a model in which early Zn-depositing brine reacted with carbonate wallrock, thereby increasing the Ca/Na ratio sufficiently to cause precipitation of early fluorite, which apparently persisted during subsequent dilution by warmer, less saline fluids. The authors data for SW sphalerite and fluorite are significantly different from fluid inclusion data reported for the Mascot-Jefferson City zinc district to the northeast, suggesting distinct brine source and evolution patterns in the two districts.

• Research Organization: Univ. of Michigan, Ann Arbor (USA)
• OSTI ID: 6576578
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Vol. 17; ISSN GAAPB
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300 -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
580400* -- Geochemistry-- (-1989)
ALKALINE EARTH METAL COMPOUNDS
BRINES
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CALCIUM FLUORIDES
CALCIUM HALIDES
CAMBRIAN PERIOD
CARBON COMPOUNDS
CARBONATE MINERALS
CARBONATES
CHEMICAL COMPOSITION
CHEMISTRY
DOLOMITE
FEDERAL REGION IV
FLUORIDES
FLUORINE COMPOUNDS
FLUORITE
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC FORMATIONS
HALIDE MINERALS
HALIDES
HALOGEN COMPOUNDS
INCLUSIONS
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALIZATION
MINERALOGY
MINERALS
NORTH AMERICA
ORES
OXYGEN COMPOUNDS
PALEOZOIC ERA
PRECIPITATION
SEPARATION PROCESSES
TENNESSEE
USA
ZINC ORES