Relation of Accumulation to Structure in Northwestern Colorado

The producing structures of northwestern Colorado are: (1) Iles dome, (2) Moffat or Hamilton dome, (3) Tow Creek anticline, (4) Thornburg dome, (5) Rangely dome, (6) White River dome, and (7) Hiawatha dome. Other seemingly favorable structures have been drilled and found barren. The producing formations range in age from Jurassic to Eocene. Oil and gas accumulation in northwestern Colorado is evidently caused by anticlinal structure. The nature of the hydrocarbons in the different structures and the lithology of the strata in which they occur indicate that the causes of accumulation were not common to all and that the folding and uplift to which they were subjected may have been factors in forming the oil and gas from the original organic material as well as being the age ts of accumulation.