Author: Edgar Odom

Publisher:

Published: 1963

Total Pages: 314

ISBN-13:

The primary objective of this investigation was to determine the vertical variations in clay mineral composition and the degree of preferred clay mineral orientation of shales and claystones ... composing the roof strata of some Illinois coal seams. Shales and claystones overlying four different Illinois coals and some samples not associated with coals were selected for this study. It is hoped that the results can be applied to the evaluation and control of roof strata in coal mines ... Some of the subordinate objectives of this investigation were to study: (l) why shales (thinly bedded sediments) occur closely associated with claystones (poorly to non-bedded sediments) when both have essentially the same clay mineral composition and seemingly were formed under similar environmental conditions; (2) why some black and gray shales are fissile whereas other black and gray shales are not; (3) what is the origin of certain types of laminations and bedding in shales, (4) what is the role of organic material in determining the properties of shales and claystones and (5) what is the origin of certain sedimentary lithoiogies in Pennsylvanian cyclothems.