Geology topics

William J. Mapel

Publications and source records attributed to William J. Mapel.

3 recordsLinked to original sources

USGS1975

Paleotectonic investigations of the Pennsylvanian System in the United States, Part I: Introduction and regional analyses of the Pennsylvanian System

The Pennsylvanian is the fourth geologic system to be analyzed and synthesized by geologists of the U.S. Geological Survey in the form of a paleotectonic study covering the conterminous United States. Earlier investigations were of the Jurassic, Triassic, and Permian Systems. Results were published as Miscellaneous Geologic Investigation Maps I-175, I-300, and I-450 and in Professional Paper 515. The objective of these investigations is to provide in graphic form the factual basis for recognition of tectonic events of each system on a countrywide scale. The maps in this publication depict rock thickness, generalized lithology, ancient geography, and other regional relations of the Pennsylvanian System. Method of preparation of the maps, the stratigraphic limits of the map units, and various stratigraphic and structural features and their probable tectonic significance are discussed. Pennsylvanian data were largely compiled between 1961 and 196 by 16 geologists, including the late Harold R. Wanless, who covered the five eastern regions and contributed to several of the special studies. The areas of responsibility of the cooperating geologists are indicated in figure 1. Work in Kansas was done by Gary F. Stewart, of the Kansas Geological Survey. Results of this investigation are presented in three units. Part I comprises an introduction and 17 chapters, each describing and discussing one of the regions in which the conterminous United States was divided for purposes of study and mapping. Part II is a synthesis of Pennsylvanian history to accompany interpretive maps of the five divisions of the Pennsylvanian System treated in this publication; it also includes a series of chapters on depositional environments, climatic conditions, and economic products of the system. The final section of part II is devoted to an index of localities and sources used in construction of the principal maps of this publication. Part III consists of the plates on which are presented the major maps and sections.

Professional Paper↗

USGS1967

Devonian of the Northern Rocky Mountains and plains

The Devonian System, represented predominantly by shallow-water marine carbonate, is widespread in Montana, Wyoming, eastern Idaho, North Dakota, South Dakota, and northwestern Nebraska. It comprises cratonic rocks in the east and miogeosynclinal rocks in the west. The cratonic rocks thicken generally northward from their southern limit in Wyoming across a broad shelf that occupies most of Wyoming and Montana. In northern Montana, they are as much as 1,250 feet thick. Cratonic rocks also thicken eastward from areas of Early Mississippian erosional thinning in central and eastern Montana to as much as 2,000 feet in the intracratonic Williston basin centered in northwestern North Dakota. The miogeosynclinal rocks, which moved eastward on low-angle thrust faults, abut against cratonic rocks along a north-trending disturbed belt in western Wyoming, western Montana and eastern Idaho. The miogeosynclinal rocks thicken abruptly westward from 1,000 feet near this belt to about 3,000 feet near the east edge of the Idaho batholith. Farther west they have been buried beneath younger rocks, altered by the batholith, or eroded. Five subdivisions of the Devonian System are treated separately: 1. Upper Lower Devonian (Coblenzian) marginal and nearshore marine carbonate rocks and related continental and estuarine discontinuous sinkhole and channel-fill deposits. 2. Upper Middle Devonian (Givetian) carbonate rocks that contain a 525-foot-thick evaporitic sequence in the Williston basin. 3. Lower Upper Devonian (Frasnian, toI ) cyclically deposited carbonate rocks that include thick beds of dolarenite and dolomitized calcarenite on the west. 4. Upper Upper Devonian (Famennian, toII-IV ) evaporitic rocks overlain by fossilferous open-marine shale and limestone. 5. Undivided uppermost Devonian (Famennian, to V-VI ) and lowermost Mississippian (Tournaisian, cuI-lower cuII α ) carbonaceous and clastic rocks deposited in six shallow basins interspersed among areas uplifted during the penecontemporaneous Antler orogeny.

Idaho, Montana, Nebraska, North Dakota, South Dako↗

USGS1954

Results of core drilling for uranium-bearing carbonaceous shale and lignite in the Goose Creek district, Cassia County, Idaho

Thirteen core holes, totaling 2,023 feet, were drilled during the fall of 1953 to explore the grade and extent of uranium-bearing beds of carbonaceous shale and lignite in the east-central part of the Goose Creek district, Cassia County, Idaho. The beds tested are interbedded with volcanic ash, bentonite, greenish-gray shale, sandstone, and conglomerate in two fairly well defined zones in the lower part of the Salt Lake formation of lower Pliocene age. Nine holes penetrated carbonaceous shale beds in the Barrett zone, and one hole penetrated carbonaceous shale and lignite beds in zone B, 160 feet stratigraphically below the Barrett zone. The highest concentration of uranium found by drilling is 0.10 percent in the upper part of a 4-foot bed of carbonaceous shale and lignite in zone B. The grade of carbonaceous shale beds in the Barrett zone ranges from 0.044 percent to less than 0.003 percent uranium. Inferred reserves in the district are estimated to be 790,000 tons in beds 1 foot or more thick containing an average of 0.014 percent or 120 tons of uranium.

Idaho↗