Abstract

, Results of a study of fluid inclusions in anhydrite from drill hole Y-6 in the Chicxulub crater, of northwestern Yucatan, Mexico, are reported in this work. The Chicxulub crater was formed at the Cretaceous-Tertiary boundary by a meteorite impact. The resulting ejection breccias are composed mostly of hydrothermally altered crystalline basement material. The mineral assemblage pyroxene + anhydrite + quartz is associated with the hydrothermal alteration. The analyzed fluid inclusions in the anhydrite show highly heterogeneous phase assemblages within the same crystal plane. Fluid inclusion types include liquid plus vapor inclusions (L+V), vapor-rich inclusions (V), and inclusions containing daughter crystals (L+V+S). The eutectic temperatures indicate a brine composition dominated by CaCl2-NaCl. Both the salinity and the homogenization temperatures show a wide range (from 3.6 to 23 wt% NaCl equivalent for the L+V inclusions, and 36 to 42 wt% NaCl equivalent for the L+V+S inclusions). The homogenization temperatures range from 100° to 500°C. These data represent cooling and boiling trends. We assume that the impact breccias were ejected at high temperature in an aqueous environment (above 500°C). This caused boiling of sea water and precipitation of anhydrite with its inclusions.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.