Abstract
Recognition of fossil silcretes may be hampered by weathering, erosion, or subsequent burial. Silcretes develop during periods of exposure and nondeposition and can represent cumulative sedimentation for geologically important periods of time. The basal Cretaceous conglomerate in north Texas (Antlers and Twin Mountains formations) was deposited and lithified on the Wichita paleoplain. The silcrete formed in a tropical climate without seasonal variation. Outcrops are sporadic yet widespread and topographically prominant. The rock is a quartz and chert-pebble conglomerate with a variety of silica cements. It is recognized as a silcrete by the following criteria. (1) Both the detrital and authigenic components are composed primarily of silica. (2) Vadose quartz overgrowths are found in association with phreatic chalcedonic cements. Vadose silt occurs with both cement types. Zonation within the cements suggests intermittant cementation. (3) Reworked cemented grains indicate syndepositional cementation, necessarily a surface phe omenon. (4) Petrified wood is abundant. Abraded petrified wood further suggests recurring silicification and transportation. End_of_Article - Last_Page 291------------
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 callDisclaimer: 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.
