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Walden P. Pratt

Publications and source records attributed to Walden P. Pratt.

At least 19 recordsLinked to original sources
USGS1997

Cross sections showing stratigraphic and depositional lithofacies of upper Cambrian rocks and the relation of lithofacies to potential for Mississippi Valley-type mineralization in the Harrison 1° x 2° quadrangle, Missouri and Arkansas (folio of the Harrison 1 degree by 2 degrees quadrangle, Missouri and Arkansas)

These cross sections are the fifth publication in a folio of maps of the Harrison 1° x 2° quadrangle, Missouri and Arkansas, prepared under the Conterminous United States Mineral Assessment Program (CUSMAP). Previously published maps in this folio relate to the geochemistry of the subsurface carbonate rocks (Erickson and others, 1989), the geophysics of the basement terranes (McCafferty and others, 1989), the sedimentary rocks and mineralization of the Caulfield district (Hayes and others, 1992), the mineral resource potential of the quadrangle (Pratt and others, 1993), and the bedrock geology of the quadrangle (Middendorf and others, 1994 and in press). A final set of maps showing locations of known Mississippi Valley-type deposits and occurrences relative to Late Cambrian shaly lithofacies and other shales in the Harrison and adjoining quadrangle is in preparation (Palmer and Hayes, in press).

Arkansas, Missouri↗
USGS1995

The Midcontinent Strategic and Critical Minerals Project; summary and background information to accompany folio of maps of the northern Midcontinent area, latitude 36-46 degrees N. and longitude 88-100 degrees W.

The Midcontinent Strategic and Critical Minerals Project was a broad investigation into the mineral-resource potential of the northern Midcontinent region of the United States. One product of the project is a folio of 10 sets of maps and one set of cross sections, all at a scale of 1:1,000,000, showing several subsurface geologic aspects of the region. This report summarizes the history of the multi-state cooperative project and the general content of the 11 map publications, and gives a visual sense of the scope and content of the folio through page-size samples of each of the map products.

Circular↗
USGS1993

Assessment of the Joplin 1° x 2° quadrangle, Kansas and Missouri, for Mississippi Valley-type deposits and other minerals

This map is a part of the folio of maps of the Joplin 1° X 2° quadrangle, Kansas and Missouri, which was prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio to date include the U.S. Geological Survey Miscellaneous Field Studies Maps MF-2125-A through D (Erickson and others, 1990; Grisafe and Rueff, 1992; Blair and others, 1992; McCafferty and Cordell, 1992). Additional maps showing other geologic aspects of the Joplin quadrangle will be published as U.S. Geological Survey maps bearing this same serial number with different letter suffixes (MF-2125-F, -G, and so on).

Kansas, Missouri↗
USGS1982

Mineral resource potential map of the Bell Mountain Wilderness Study Area, Iron County, Missouri

Under the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and the Joint Conference Report on Senate Bill 4, 88th Congress, the U.S. Geological Survey and U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the Act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The Act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. This report discusses the results of a mineral survey of some national forest lands in the Bell Mountain Wilderness Study Area, Iron County, Missouri.

Missouri↗
USGS1982

Mineral resource potential map of the Rock Pile Mountain Wilderness Study area, Madison County, Missouri

Although the Rock Pile Mountain Wilderness Study Area is within the general boundary of the Southeast Missouri mining district, it has no record of mineral production and there is no mining or prospecting activity at present. Exploratory drill holes on private land along the west side of the area encountered no economic mineralization. Neither the Precambrlan volcanic rocks nor the Cambrlan sedimentary rocks contain any detectable evidence of economic mineralization. The area has no potential for coal resources, an unfavorable potential for oil and gas, and no known potential for geothermal energy. The volcanic rocks might be suitable for use as crushed stone, but similar rocks occur abundantly in more favorable locations elsewhere.

Missouri↗
USGS1982

Geologic, geochemical and mineral resource potential map of the Piney Creek Wilderness, Stone and Barry counties, Missouri

There is no evidence of significant metallic-mineral deposits in the rock units that are exposed at the surface in the wilderness, but there may be some potential for mineral deposits of two different types at depths from 400ft (120 m) to more than 2,100 ft (640 m) below the surface. Analyses of rock samples from a drill hole 15 mi (24 km) south of the area showed anomalous amounts of several metals in the Derby-Doerun (usage of the Missouri Geological Survey), Potosi, and Eminence Dolomites, which suggests that these units as well as the subsurface Ordovician carbonate units may have a potential for zinc-lead mineralization in the wilderness. Also, a high-amplitude magnetic anomaly along the northwest side of the wilderness suggests a potential for a small to moderate-sized magnetite (iron ore) deposit in the Precambrian basement rocks at a depth of at least 2,100 ft (640 m) below the surface, probably at least partly outside the boundary of the wilderness. In both cases the significance of the potential cannot be evaluated without deep drilling. In the case of the possible magnetite deposit, drilling should be preceded by a detailed magnetic survey to delineate the anomaly more clearly. The wilderness has little potential for resources of industrial minerals because they are readily available elsewhere in the region, and no known potential for energy resources.

Missour↗
USGS1973

Submarine chert-argillite slide-breccia of Paleozoic age in the southern Klamath Mountains, California

A unique chert-argillite breccia—a breccia with an argillite matrix, in which nearly all the fragments are chert—underlies an area of at least 60 sq mi in the southern Klamath Mountains of California. Rocks of this composition have not been reported previously, in the Klamath Mountains or elsewhere, but in northwestern Trinity County they make up a large part of the western Paleozoic and Triassic belt. The remainder of the belt consists of northerly trending sinuous zones of two other principal lithologies: radiolarian chert, rhythmically interbedded with slate or phyllite, crops out in three zones in the eastern, central, and western parts of the area; and massive metabasalt and metadiabase intruded by gabbro and serpentinite occur in a zone about 3 mi wide in the eastern part of the area. Although the predominance of chert fragments makes the chert-argillite breccia apparently unique, rocks that are generally similar, consisting of angular to subangular clasts in a pelitic matrix, have been studied in many localities. Field relations and petrographic features of the chert-argillite breccia—specifically the angularity of clasts, absence of a sandy matrix, preservation of Radiolaria in both chert clasts and pelitic matrix, presence of contorted flow laminae in the matrix, large size of some of the exotic blocks, close association with chert, pillow lava, and limestone, absence of stretching or slickensiding of clasts, and overall dimensions of the unit measurable in miles—variously preclude origin of the rock as a normal sedimentary conglomerate, a tectonic breccia, a tillite, or a subaerial mudflow, but include features common to numerous submarine-slide deposits. We interpret the chert-argillite breccia as the result of uplift and subsequent sliding of a thick deposit of inter-layered chert and pelitic ooze. Brittle fracturing of the chert and mobilization of water-saturated ooze produced the observed features. Fossiliferous limestone blocks within the slide-breccia indicate that it is no older than Silurian or Devonian, and it predates Jurassic metamorphism and plutonism. The relation of the breccia to a major northwest-trending fault zone, and to serpentinite within this zone, suggests that the formation of the breccia was generally synchronous with the faulting and ultramafic intrusion. Rocks of the central metamorphic belt, east of the mapped area, were metamorphosed during a Devonian orogeny, and we suggest that the submarine slide-breccia was formed as a frontal effect of the same orogeny.

California↗