Devonian stratigraphy and paleontology of the Roberts Mountains region, Nevada

Studies of middle Paleozoic history in western America have long been delayed. For the past 50 years efforts of stratigraphers on the Pacific Coast have been devoted largely to investigation of Mesozoic and Cenozoic strata, good outcrops of which are found in the vicinity of several western centers of geologic research. Moreover, growing importance of geology in the petroleum industry has given vital encouragement to study of the younger strata. Remote and somewhat difficult of access, the Paleozoic areas have received but small share of the attention they justly deserve. Conclusions regarding the older systems have thus remained speculative in absence of field evidence which would permit a scientific attack. In the eastern States, particularly New York, even a century of progress in Paleozoic stratigraphy still leaves many unsolved problems. It is not surprising then that knowledge of some Paleozoic systems in the west is still insufficient to make possible even satisfactory definition of the problems themselves. While the western Cambrian faunas have become reasonably well known through the vigorous collecting program of Charles D. Walcott and his associates, and while the Carboniferous strata and faunas have received a fair amount of study, the intermediate systems have until recently remained almost untouched since the days of federal exploring expeditions in the western territories. Following the exploratory phase of western geology in the latter half of the past century, study of western middle Paleozoic stratigraphy was for the most part incidental to mapping programs in mineralized regions where the structure is . . .