PERMIAN SURFACE-WATER TEMPERATURES FROM NIPPEWALLA GROUP HALITE, KANSAS

Primary fluid inclusions in evaporite minerals may yield significant data on local paleoclimates. This method requires initial nucleation of vapor bubbles in all liquid inclusions, followed by measurement of the temperatures at which these inclusions homogenize to liquid. This paper presents surface water paleotemperatures from primary, originally all liquid fluid inclusions in middle Permian Nippewalla Group halite from southwestern Kansas. One phase aqueous primary fluid inclusions in Nippewalla Group halite were cooled in order to nucleate vapor bubbles. Their homogenization temperatures range from 32 degrees C to 46 degrees C and are relatively consistent along individual chevron and comet growth bands. These data fall within the same range as modern evaporative surface waters, suggesting that this Permian environment was relatively similar to its modem counterparts. Reproducible, consistent homogenization temperatures indicate fluid inclusions have not been altered by thermal reequilibration and that this method for determining surface water paleotemperatures is valid The future application of this method to numerous ancient evaporites may result in a wealth of quantitative local paleoclimate data.