UPPER CRETACEOUS STRATIGRAPHY, PALEONTOLOGY, AND PALEOECOLOGY OF WESTERN KANSAS by Donald E. Hattin INTRODUCTION Objectives of the Trip Spectacular fossils in Upper Cretaceous rocks of western Kansas have excited paleon- tologists for nearly a century and have lured generations of enthusiastic collectors to concretion-strewn shale slopes and chalk badlands that break the monotony of the Great Plains. For decades, writers of historical geology textbooks have embellished their chap- ters on the Cretaceous with illustrations of the mosasaurs, pterosaurs, cephalopods, pele- cypods, crinoids, and plant remains that have earned the Kansas Cretaceous a place of en- during fame in the annals of American paleontology. From earliest beginnings in fossil collection and description, study of these rocks evolved to a stage of mapping and descrip- tion of strata which is now giving way to studies devoted to petrogenesis, paleoecology, and refinements in biostratigraphy. This field excursion is designed to acquaint participants with details of the vertical succession of marine Upper Cretaceous strata in Kansas and to afford opportunity for collect- ing representative suites of invertebrate fossils from each rock unit. To this end a group of remarkable exposures has been selected for examination of a complete section extending from the upper part of the Dakota Formation upward into the lower part of the Niobrara Chalk. Additional exposures to be visited are representative of the upper part of the Nio- brara and lower part of the Pierre Shale. At each stop discussion will center on critical aspects of lithostratigraphy, biostratigraphy, paleoecology, and general depositional his- tory of the units exposed. Acknowledgments The writer gratefully acknowledges the aid given by the following persons during prep- aration of this guidebook: typing - Janet Griffin and Sherry Thomas, Indiana University; photography - George Ringer, Indiana University; drafting - Bill Moran, Indiana University. Gary F. Stewart, State Geological Survey of Kansas, helped to log the route of the trip and Dr. W. A. Cobban, U. S. Geological Survey, furnished the section on the Pierre Shale, the photographs of Baculites asperiformis, and the graphic column of the Pierre Shale at Stop 6. 1