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James Bachelder Cathcart

Publications and source records attributed to James Bachelder Cathcart.

At least 19 recordsLinked to original sources
USGS1984

Phosphate rock resources of the United States

In 1980, the United States produced about 54 million tons of phosphate rock, or about 40 percent of the world's production, of which a substantial amount was exported, both as phosphate rock and as chemical fertilizer. During the last decade, predictions have been made that easily ruinable, low-cost reserves of phosphate rock would be exhausted, and that by the end of this century, instead of being a major exporter of phosphate rock, the United States might become a net importer. Most analysts today, however, think that exports will indeed decline in the next one or two decades, but that resources of phosphate are sufficient to supply domestic needs for a long time into the future. What will happen in the future depends on the actual availability of low-cost phosphate rock reserves in the United States and in the world. A realistic understanding of future phosphate rock reserves is dependent on an accurate assessment, now, of national phosphate rock resources. Many different estimates of resources exist; none of them alike. The detailed analysis of past resource estimates presented in this report indicates that the estimates differ more in what is being estimated than in how much is thought to exist. The phosphate rock resource classification used herein is based on the two fundamental aspects of a mineral resource(l) the degree of certainty of existence and (2) the feasibility of economic recovery. The comparison of past estimates (including all available company data), combined with the writers' personal knowledge, indicates that 17 billion metric tons of identified, recoverable phosphate rock exist in the United States, of which about 7 billion metric tons are thought to be economic or marginally economic. The remaining 10 billion metric tons, mostly in the Northwestern phosphate district of Idaho, are considered to be subeconomic, ruinable when some increase in the price of phosphate occurs. More than 16 billion metric tons probably exist in the southeastern Coastal Plain phosphate province, principally in Florida and North Carolina and offshore in the shallow Atlantic Ocean from North Carolina to southern Florida. This resource is considered to be hypothetical because it is based on geologic inference combined with sparse drilling data. Total resources of phosphate rock in the United States are sufficient to supply domestic demands for the foreseeable future, provided that drilling is done to confirm hypothetical resources and the chemistry of the deposits is determined. Mining and beneficiation techniques will have to be modified or improved, and new techniques will have to be developed so that these deposits can be profitably exploited.

Circular↗
USGS1981

A summary of phosphate-rock resources of the United States-an analysis of past estimates

The United States produced in 1980 about 54 million tons of phosphate rock, which was 40 percent of the world production. About 62 percent of this production was exported, 28 percent as phosphate rock and 34 percent is manufactured fertilizers and chemicals. The remainder was used domestically, largely (88 percent) for fertilizer and animal feed supplement to produce agricultural products (U.S. Bureau of Mines, 1981). A significant portion of these agricultural products was exported, so the phosphate rock that went into that portion was exported indirectly. Thus, most phosphate production is exported directly or indirectly and contributes to the U.S. balance of international payments. Although the marketable value of the phosphate rock produced in 1980 was only about $1.2 billion, the total value of the agricultural and chemical products depending on phosphate rock input is many times that. The continued ability of the U.S. phosphate industry to supply low-cost phosphate rock for export and domestic consumption is clearly of major importance to the Nation.

Open-File Report↗
USGS1975

Uranium in phosphate rock

Uranium is a trace constituent of all apatites in amounts that typically range from <0.001 to 0.003 percent for guano and guano-derived deposits; from 0.001 to 0.010 percent for igneous apatites; from 0.005 to 0.030 percent for marine phosphorites. Uranium may be enriched to as much as 0.05 percent in phosphorites reworked in a marine environment, and isolated bones and concretions may contain as much as 0.8 percent uranium as a result of enrichment by ground water. Uranium as U(IV) replaces calcium in the apatite structure. Possibly some U(VI) occurs as U0 4 -2 groups. Uranium is readily removed from apatite by weathering, and enrichment of phosphate after deposition may be entirely residual, as in the case of the brown rock deposits of Tennessee, or uranium may be added as in the case of the lateritic weathering of the deposits in Florida. Uranium has been recovered as a byproduct of the manufacture of phosphoric acid by the wet process. In 1972, about 15 million tons of phosphate rock was used to make phosphoric acid in the United States. This phosphoric acid probably contained about 1500 tons of uranium. An additional 10 million tons, worldwide, was made into phosphoric acid, and thus, 1000 tons of uranium was in solution. Increased demand for phosphatic fertilizers and increases in the amount of phosphate rock used to make phosphoric acid makes it likely that tonnages of uranium in phosphoric acid will reach 5000 tons per year within the next 25 years. Thus, marine phosphorites are a significant source of uranium for the future.

Open-File Report↗
USGS1974

Geology and mineralogy of phosphate rock in the Bambui group near Cedro do Abaete and vicinity, Minas Gerais, Brazil

Discontinuous lenticular masses of phosphate rock are present near or at the contact between the green mudstone and the underlying red and yellow clay-stone units of the Serra da Saudade Member of the Rio Paraopeba Formation of the Bambui Group of late Precambrian to early Paleozoic age. The lenses are as much as 8 meters thick and 400 meters long. The phosphate rock is folded and faulted and is overlain by flat-lying rocks of Cretaceous age. The phosphate mineral is a carbonate fluorapatite, but only a small amount of C0 2 substitutes for PO 4 . Crystalline apatite in veinlets is clearly younger than the groundmass apatite, and contains almost no C0 2 . Surficial parts of the phosphate lenses have been altered to a rock characterized by aluminum phosphate. Samples of the green mudstone contain muscovite-illite, quartz, and what is believed to be glauconite. Samples collected adjacent to the phosphate lenses also contain veinlets of apatite or wavellite. Chemical analyses of the phosphate rock show that it contains from 16 to 35 percent P 2 0 5 , and all samples are deficient in Ca0 relative to P 2 0 5 , indicating that some of the phosphate in all samples is combined with alumina. The samples contain as much as 8 percent K 2 0 in the minerals muscovite-illite or glauconite. All the samples collected are extremely fine grained. The rocks are laminated and show the effects of slight deformation; for example, crumpled bedding, offset veinlets, and slight development of muscovite along bedding planes. The phosphate probably is not economically important on the world market, but possibly could be used locally for direct application depending on agricultural lands.

Minas Gerais↗
USGS1971

Phosphate investigations in Colombia, 1969 a progress report; with a note on the aluminous laterite deposits of the Department of Cauca

About 10 weeks were spent in Colombia from January through March 1970 examining the progress of the phosphate investigations. Field work was done in the Sogamoso area, where detailed mapped by geologists of the Instituto Nacional de Investigaciones Geologico-Mineras has shown a large area where structures are gentle and not too complex, and as a consequence, the phosphorite beds are in a potentially minable situation. The beds in the Sogamoso area are in the sandy facies of the late Cretaceous miogeosyncline, and weathered surface rocks are deficient in CaO, so that a part of the P 2 O 5 in these rocks is present as wavellite. No unweathered samples have been collected, but it is thought that fresh material may contain some calcite. Drilling to confirm structure and to obtain unweathered samples started in March 1970. This area is promising economically. Resources of phosphorite in the southern part of the country, in the Departments of Huila and Tolima, are not as promising as are the resources in the Sogamoso area. The southern area is at or close to the linebetween the sandy and the calcareous facies of the miogeosyncline, andthus much of the material contains excess CaO. The structure is more complex, and the phosphorite beds are thinner than in the Sogamoso area, and much of the area is covered by a thick section of continental Tertiary sediments. A very short visit was made to the sulfur mine on Purace volcano. The ore is native sulfur impregnating very recent tuffs. Sulfur was deposited by fumaroles. Although known reserves are small, much of Purace volcano has not been explored, and there is potential for additional reserves. Other volcanoes in the southern part of Colombia should also be investigated to determine their potential as a source of sulfur. A few days were spent examining the aluminous laterite deposits in the Department of Cauca. The deposits are formed from intense lateritic weathering of Plio-Pleistocene tuff beds. The tuffaceous material is completely destroyed in the weathering,leaving a soft, very fine grained, very wet clay-like material. On drying, aggregates of gibbsite are formed and these are stable. It is thought that Al 2 O 3 , Fe 2 O 3 , and a part of the SiO 2 in the clayey material may be non-crystalline. Reserves of the material are very large, and further work is definitely indicated.

Open-File Report↗
USGS1967

Phosphate rock in Colombia - a preliminary report, with a section on the phosphate occurrence at Turmeque

Exploration for phosphate rock in Colombia was successfully carried out in 3 1/2 months by the U.S. Geological Survey and the Inventorio Minero of the Servicio Geologico Nacional, under the auspices of the U.S. Agency for International Development. A modern theory of exploration based on model studies of phosphorite deposits is that phosphate is deposited in the miogeosyncline adjacent to the foreland or craton, where parts of the ocean are deep, where deposition of clastic material is at a minimum, and where upwelling currents deposit a suite of rocks characterized by chert, black shale, carbonate rock, and phosphorite. Although phosphate is found in rocks of all geologic periods, economic deposits are known only in certain of: the periods--one of these being the Late Cretaceous. As previous work had demonstrated that phosphate is present in Colombia only in rocks of Cretaceous age, and is most abundant in rocks of Late Cretaceous age--the La Luna Formations and Guadalupe--in the Cordillera Oriental, work was accordingly confined to the Cordillera Oriental and to rocks of Late Cretaceous age. Particular emphasis was paid to facies changes in the miogeosyncline; the field investigation pointed to the area in Norte de Santander where the best phosphorite was found. Phosphate deposits were found in both the geosynclinal and the platform facies in Upper Cretaceous rocks spread through a large area of the Cordillera Oriental, from Huila in the south to Norte de Santander in the north, a distance of more than 600 kilometers.

Open-File Report↗