Late Cretaceous (Cenomanian-Coniacian) calcareous nannofossil biostratigraphy and paleoecology of the Western Interior Basin, USA

TL;DRAbstract

Analysis of calcareous nannofossil biostratigraphy and paleoecology is performed for eight sites within the central (Mesa Verde National Park, CO; Rock Canyon Anticline, Pueblo, CO; Rt. 36, Cuba, KS) and southern (Lozier Canyon, Terrell Co., TX; industry drillcores, Webb Co., TX; ACC #1 Core, Austin, TX) Western Interior Basin (WIB). A study of nannofossil first and last occurrences from these sites in the WIB and coeval successions in the literature results in a high-resolution optimum sequence of events for the Late Cenomanian through Coniacian using the statistical method of Ranking and Scaling (RASC). Additional taxonomic work on the transitional forms in the Eprolithus-Lithastrinus lineage provides reliable criteria for distinguishing two taxa, Eprolithus moratus and Lithastrinus septenarius, for more accurate use in this sequence. The RASC optimum sequence is contrasted with the placement of key nannofossil bioevents in the revised 2012 edition of the geologic timescale (Ogg and

Chat with Paper

AI Agents for this Paper