Preliminary investigation of the geologic setting and chemical composition of the Pierre Shale, Great Plains region
._ _-___-__-_--______-______-___--__-__--_Introduction _______________________________________ Plan of study, _____________________________________ Acknowledgments__ ___-_-___---_-____---_--_______ Distribution of Pierre shale and equivalent rocks. ______ Stratigraphic relations of the Pierre shale and equivalent rocks_ ____________________________________________ Historical summary.____________________________ Correlation of units.____________________________ Description of units.____________________________ Facies belts._---__----------_-_-.-_-_-__------_ Geochemical history___----------_____-__-----_--_ Samples -_--_-_-----__________________________-____ Terminology ___________________________________ Field investigations.____________________________ Laboratory investigations..._.--___-_____________ Physical composition._______________________________ Size analyses.__________________________________ Mineralogy _________________________________ Material coarser than 74 microns _____________ X-ray analyses _____________________________ Chemical composition_______________________________ Average composition of selected samples of Pierre shale.-------___-___-________________________ Major constituents._____________________________ Mode of occurrence_________________________ Statistical distribution_____________________ Page 1