Biotic Patterns Across the Cenomanian-Turonian Extinction Boundary Near Pueblo, Colorado
William P. Elder, 1985. "Biotic Patterns Across the Cenomanian-Turonian Extinction Boundary Near Pueblo, Colorado", Fine-Grained Deposits and Biofacies of the Cretaceous Western Interior Seaway: Evidence of Cyclic Sedimentary Processes, Lisa M. Pratt, Erle G. Kauffman, Frederick B. Zelt
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The Cenomanian-Turonian boundary extinctions, as observed near Pueblo, Colorado, are represented by a series of events reflecting accelerated macrofaunal evolutionary and extinction rates. Four main events are recognized near Pueblo which are cumulatively responsible for 80% species-level and about 30% genera-level macrofaunal extinction. The two main extinction events near Pueblo occured about 250 and 200 Ka before the terminal extinctions at the stage boundary. In addition to the evolutionary and extinction related faunal turnover, fluctuations in the relative abundances of inoceramid bivalves, oysters and ammonites appear to be related to substrate and inferred habitat changes reflected by the climatically controlled lithologie cyclicity. The increased rates of evolution and extinction observed through the Cenomanian-Turonian boundary interval may have been driven by increased biotic stress resulting from eustatic highstand and increased climatic variability influencing temperature, salinity, and benthic oxygenation within the Western Interior seaway and globally.
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Fine-Grained Deposits and Biofacies of the Cretaceous Western Interior Seaway: Evidence of Cyclic Sedimentary Processes
Fine-Grained Deposits and Biofacies of the Cretaceous Western Seaway: Evidence of Cyclic Sedimentary Processes - This volume emphasizes the influence of cyclic sedimentary processes on the distribution of rock types and faunas in the Cretaceous strata in Colorado. As a whole, the volume provides an interdisciplinary view of the causes and consequences of gradual cyclic, periodic, and catastrophic changes in environmental conditions recorded by strata in the Kiowa-Skull Creek, Greenhorn, and Niobrara Cyclothems.