Search USGS⌕ Search

Geology topics

Paul Averitt

Publications and source records attributed to Paul Averitt.

At least 19 recordsLinked to original sources
USGS1953

Coal resources of the United States (a progress report, October 1, 1953)

As estimated in this second progress report, the coal reserves of the United States remaining in the ground on January 1, 1953, total 1,899,739 million tons. This figure is about a 20 percent reduction of the total estimate published in the first progress report (Averitt and Berryhill, 1950). The new total is based on new, detailed, conservative estimates of reserves in Indiana, Michigan, Montana, New Mexico, North Carolina, North Dakota, South Dakota, Virginia, and Wyoming, prepared since 1947 by the U. S. Geological Survey; on new provisional, but equally conservative estimates of reserves in Colorado, Maryland, and Georgia, based on previous work of the U. S. Geological Survey and other agencies; on estimates of reserves in Illinois, Kansas, Pennsylvania, and West Virginia, prepared by the geological surveys of those States; and on older and incompletely documented estimates for the remaining states. The older estimates were prepared on a highly generalized basis and were intended to represent total possible reserves in both thick and thin beds and under both light and heavy overburden. The recent estimates have been prepared on a more conservative basis than the older estimates and tend to be considerably smaller. New conservative estimates have now been prepared for 16 coal-bearing States, which include about two-thirds of the total estimated reserves of the United States. As new estimates are prepared for the remaining States a further reduction of the total reserve figure is in prospect, though the reserves still will be large. The estimated recoverable reserves of the United States as of January 1, 1953, total 949,870 million tons, based on the assumption that half of the coal reserves in the ground will be lost in mining, and half will be recovered. The distribution of the remaining and recoverable reserves by rank is shown in the accompanying table. The reserves in 10 States have been classified in considerable detail according to thickness of beds, thickness of overburden, and relative abundance of reliable information available for making estimates. In these States, which are representative of several coal provinces, and contain about 40 percent of the total reserves, and are thus typical of the United States as a whole, 5 percent of the total is measured reserves in beds 28 inches or more thick, and less than 1,000 feet below the surface; and 20 percent is indicated reserves within the same limit of thickness and less than 2,000 feet below the surface. The remaining 75 percent is inferred reserves, reserves in thin beds, and reserves 2,000 to 3,000 feet below the surface. The large percentage of inferred reserves obviously includes some coal in thick beds, which for lack of detailed information cannot be appraised quantitatively. Although accurately based on the data now available, the distribution percentages are subject to considerable change as new work is completed, particularly in the transfer of reserves from the indicated and inferred categories to the measured category. The figures serve, however, to indicate the present state of knowledge of the Nation's coal reserves, and they point to the need for additional geologic mapping and exploration.

Circular↗
USGS1953

Geology and geography of the Henry Mountains region, Utah

The Henry Mountains region in southeastern Utah is one of the classic areas in geology because of the study made there by Grove Karl Gilbert in 1875 and 1876. His report on the geology of the mountains was the first to recognize that intrusive bodies may deform their host rocks and the first to show clearly the significance of the evenly eroded plains, now known as pediments, at the foot of desert mountains. The Henry Mountains with the surrounding structural basin is a rugged, dry, and sparsely settled region, a part of the Colorado Plateaus province. The natural obstacles of the region-the aridity and ruggedness-have kept it primitive. It has not been penetrated by modern methods of transportation and thus it persists as a roadless frontier. Even the Indians seem to have made little use of the region; explorers did not enter it until 1869 and settlements were not started until the eighties.

Utah↗
USGS1951

Coking-coal deposits of the western United States

Geohydrologic systems in the Anadarko basin in the central United States are controlled by topography, climate, geologic structures, and aquifer hydraulic properties, all of which are the result of past geologic and hydrologic processes, including tectonics and diagenesis. From Late Cambrian through Middle Ordovician time, a generally transgressive but cyclic sea covered the area. The first deposits were permeable sand, followed by calcareous mud. During periods of sea transgression, burial diagenesis decreased porosity and permeability. During Pennsylvanian time, rapid sedimentation accompanied rapid subsidence in the Anadarko basin. A geopressure zone probably resulted when sediments with little permeability trapped depositional water in Lower Pennsylvanian sands. Burial diagenesis included compaction and thermal alteration of deeply buried organic material, which released carbon dioxide, water, and hydrocarbons. By Middle Pennsylvanian time, the sea had submerged most of the central United States, including the Ozarks, as tectonic activity reached its maximum. During Late Pennsylvanian and Early Permian time, the Ouachita uplift had been formed and was higher than the Ozarks. Uplift was accompanied by a regional upward tilt toward the Ouachita-Ozarks area; the sea receded westward, depositing large quantities of calcareous mud and clay, and precipitating evaporitic material in the restricted-circulation environment. By the end of Permian time, > 20,000 ft of Pennsylvanian and Permian sediments had been deposited in the Anadarko basin. These thick sediments caused rapid and extreme burial diagensis, including alteration of organic material During Permian time in the Ozarks area, development of the Ozark Plateau aquifer system commenced in the permeable Cambrian-Mississippian rocks near the St. Francois Mountains as the Pennsylvanian confining material was removed. Since Permian time, uplift diagenesis has been more active than burial diagenesis in the Anadarko basin. Synopsis of paleohydrologic interpretation indicates that Cambrian-Mississippian rocks in the Anadarko basin should be relatively impermeable, except for local secondary permeability, because rocks in the basin have undergone little uplift diagenesis. (Lantz-PTT)

Circular↗
USGS1950

Coal resources of the United States, A progress report, November 1, 1950

Interest in the quantity and quality of the coal reserves of the United States has increased greatly since the end of World War II, principally because of the growing realization that the ultimate reserves of petroleum and natural gas, although largely undefined, still. have finite limits. With the greatly increased use of petroleum and natural gas, it has become further apparent that the reserves of these two fuels, whatever their ultimate limits may prove to be, are being consumed at a rate far surpassing that anticipated a few years ago. At some time in the future, therefore, the contribution of coal to the total production of energy in this country must inevitably be enlarged to include some of the needs now served by petroleum and natural gas. Although coal-bearing rocks cover 14 percent of the total area of the United States (fig. 1) and contain enormous reserves, it is equally apparent that reserves of coal also have limits. In the extensively mined sections in the East it is already increasingly difficult to locate new areas containing thick beds of high-rank and high-quality coal to replace areas that have been mined out. Furthermore, a considerable part of the total reserves of the United States consists of coal of lignite and subbituminous ranks and coal contained in thin beds that can be mined only with great difficulty and expense. At the present time, therefore, the depletion of reserves of high-rank and high-quality coal, particularly the Eastern coal that is suitable for the manufacture of metallurgical coke, is a more serious problem than the percentage depletion of the total coal reserves. Recognizing the need for more detailed estimates of coal reserves than those that have been available in the past, the U. S. Geological Survey is now preparing a reappraisal of the coal reserves of the United States in which primary emphasis is placed on the amounts of coal in separate categories according to rank,thickness of coal, and thickness of overburden. Many of the state geological surveys in coal-producing areas are also preparing new appraisals of coal reserves. The increasing volume of geologic data available on the occurrence of coal and the detailed and careful methods now employed in calculating reserves should ultimately provide a more reliable estimate for the coal reserves of the United States than has been obtainable previously, although much additional work remains to be done.

Circular↗