MINERAL AND ORGANIC DISTRIBUTIONS AND RELATIONSHIPS ACROSS THE GREEN RIVER FORMATION'S SALINE DEPOSITIONAL CENTER, PICEANCE CREEK BASIN, COLORADO

摘要

Stratigiraphically correlated profiles of organic matter concentration and profiles of 8 major mineral X-ray diffraction peak heights in oil shales, through Colorado's Green River Formation near its saline depositional center, are presented in histogram form. The profiles are used to show distributions and relationships of the minerals and organic matter. Strong direct relationships between the volume of organic matter in Colorado's Green River Formation oil shales and the relative amounts of the silicate minerals—quartz, soda feldspar, and potash feldspar were demonstrated singly and collectively. The silicate minerals were also shown to be directly related to each other. Dawsonite in the saline zone of the Formation was also shown to be directly related to the volume of organic matter and indirectly to the amount of nahcolite. These relationships were all interpreted as the result of C02 evolution from organic matter in the sediment. A strong direct relationship demonstrated between dawsonite and quartz was credited to both the organic C02 mechanisms and to ash-fall decomposition.