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Frank W. Osterwald

Publications and source records attributed to Frank W. Osterwald.

13 recordsLinked to original sources

Effects of coal mine subsidence in the Sheridan, Wyoming, area

Analyses of the surface effects of past underground coal mining in the Sheridan, Wyoming, area suggest that underground mining of strippable coal deposits may damage the environment more over long periods of time than would modern surface mining, provided proper restoration procedures are followed after surface mining. Subsidence depressions and pits are a continuing hazard to the environment and to man's activities in the Sheridan, Wyo., area above abandoned underground mines in weak overburden less than about 60 m thick and where the overburden is less than about 10-15 times the thickness of coal mined. In addition, fires commonly start by spontaneous ignition when water and air enter the abandoned mine workings via subsidence cracks and pits. The fires can then spread to unmined coal as they create more cavities, more subsidence, and more cracks and pits through which air can circulate. In modern surface mining operations the total land surface underlain by minable coal is removed to expose the coal. The coal is removed, the overburden and topsoil are replaced, and the land is regraded and revegetated. The land, although disturbed, can be more easily restored and put back into use than can land underlain by abandoned underground mine workings in areas where the overburden is less than about 60 m thick or less than about 10-15 times the thickness of coal mined. The resource recovery of modern surface mining commonly is much greater than that of underground mining procedures. Although present-day underground mining technology is advanced as compared to that of 25-80 years ago, subsidence resulting from underground mining of thick coal beds beneath overburden less than about 60 m thick can still cause greater damage to surface drainage, ground water, and vegetation than can properly designed surface mining operations. This report discusses (11 the geology and surface and underground effects of former large-scale underground coal mining in a 50-km 2 area 5-20 km north of Sheridan, Wyo., (2) a ground and aerial reconnaissance study of a 5-km^2 coal mining area 8-10 km west of Sheridan, and (31 some environmental consequences and problems caused by coal mining.

Professional Paper

Effects of coal mine subsidence in the western Powder River basin, Wyoming

Analyses of the surface effects of past underground coal mining in the western Powder River Basin suggest that underground mining of strippable coal deposits will damage the environment more over long periods of time than will modern surface mining, provided proper restoration procedures are followed after surface mining. Subsidence depressions and pits are a continuing hazard to the environment and to man's activities 5-20 km north of Sheridan, Wyo., above mines that were abandoned 25-80 years ago where the overburden is weak and is less than about 60 m thick. In addition, fires commonly start by spontaneous combustion when water and air enter the abandoned mine workings via subsidence cracks and pits. The fires can then spread to unmined coal as they create more cavities, more subsidence, and more cracks and pits through which air can circulate. In modern surface mining operations the total land surface underlain by minable coal is removed to expose the coal. The coal is removed, the overburden and topsoil are replaced, and the land regraded and revegetated. The land, although disturbed, can be more easily restored and put back into use than land underlain by abandoned underground mine workings in areas where the overburden is less than about 60 m thick. The resource recovery of modern surface mining also is much greater than that of underground mining procedures. Although present-day underground mining technology is advanced as compared to that of 25-80 years ago, subsidence resulting from mining of thick coal beds beneath overburden less than about 60 m thick by underground methods can cause greater damage to surface drainage, ground water, and vegetation than can properly designed surface mining operations. This report briefly discusses the geology and surface and underground effects of former large-scale underground mining in a 50 km2 area north of Sheridan, Wyo. and describes some environmental consequences and problems caused by mining.

Wyoming

Summary of seismic activity and its relation to geology and mining in the Sunnyside mining district, Carbon and Emery Counties, Utah, during 1967-1970

In the Sunnyside mining district, Utah, coal is mined under thick and variable overburden which is locally weakened by faults and other structural discontinuities. Stress changes and local stress concentrations produced by mining under these conditions often cause sudden and violent ruptures in the coal and surrounding rock mass. The strain energy released by this type of failure, which can produce shock waves and may discharge coal and rock with explosive force, is often a serious threat to life and property. These releases of strain energy are called bumps or bounces by miners if they occur in the coal, and rock bursts if they occur in the surrounding rock mass. Many of these releases are so violent that they generate seismic waves that can be felt, or at least detected by seismic instruments, miles from the site of the rupture, whereas others are smaller and can be detected only by those sensitive seismic instruments within a few thousand feet of the site of the rupture. In 1969 and 1970, about 27,000 and about 15,000 earth tremors, respectively, were recorded by the five-station seismic monitoring network that is located at the surface and encompasses most of the mine workings in the district. Of these totals, 512 and 524 earth tremors, respectively, were of sufficient magnitude (greater than 1. 5 on the Richter scale) so that the hypocenters could be accurately located. In 1968 about 20,000 tremors were recorded, with 281 large enough to plot, but in 1967 over 50,000 were recorded, of which 540 were plotted. In this report we discuss the way in which seismic activity, geology, and mining are related or seem to be related for the period 1967 through 1970, with emphasis on the period 1969-70. We also suggest certain mining procedures which, based on studies during the period, might increase the safety and efficiency of mining operations in the Sunnyside district. A complete tabulation of the larger magnitude earth tremors which occurred during 1969-70 and descriptions of how they relate to mining are given in the appendix. Similar tabulations and descriptions for 1967 and 1968 are available in earlier reports (Barnes and others, 1969; Dunrud and others, 1970).

Open-File Report

Some engineering geology problems at Mammoth Cave National Park, Kentucky

The U.S. Geological Survey, at the request of the rational Park Service, participated in a field symposium May 22-26, 1967, at Mammoth Cave National Park, Kentucky. This symposium, held by the National Park Service, was to determine the applicability of the Wilderness Act of 1964 to underground and surface portions of the Park (W. Drew Chick, Jr., written communication, 1967). Scientific evidence bearing on the relationships between human surface activities and natural underground openings was examined and discussed at the symposium. This report discusses relations between various types of surface activities and physical damage to the cave openings and features. Additional interpretive material is taken from the literature and from limited laboratory information. Possible hydrologic and biologic effects are not considered here, but were investigated by other members of the symposium. Hydrologic effects are discussed in companion report by Robert V. Cushman of the Geological Survey.

Kentucky

Geology applied to study of coal mine bumps and mining methods at Sunnyside, Utah

Coal mine bumps are a serious hazard to life and property in the mines of east-central Utah. Research into geologic factors associated with these bumps indicates that the bumps are spatially and genetically related to structural and stratigraphic features. Some bumps are directly related to stress accumulation along faults, either from natural causes or as a result of mining. Frictional properties of bedding planes between coal and roof rock, and between some rock units within the roof, directly affect the deformation of coal ribs, and hence the incidence of bumps. These frictional properties are related to the lithology of the roof rocks as well as to the sedimentary structures within the rocks. Commonly a sequence consisting of 1- 3 ft of carbonaceous siltstone, about 2- 3 ft of rider coal, and several feet of massive siltstone or sandstone overlies the main seam. The sequence causes difficult roof conditions in the mines, difficult mining conditions, and directly or indirectly many bumps.

Utah

Geologic maps of the Eureka Gulch area, Central City district, Gilpin County, Colorado

These maps are of the historic Eureka Gulch area of the Central City silver district, southern Gilpin County, Colorado. The mapping was done on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission, as part of a study of the Central City and Idaho Springs districts and was designed to furnish geologic data for use in appraising the uranium reserves of the area.

Colorado