Sandstone deposits

Domestic. Estimates of U.S. uranium resources for reasonably assured resources, estimated additional resources, and speculative resources at costs of 80, 130, and 260/kg of uranium are given in Table 1 (18). These estimates include only conventional uranium resources, which principally include sandstone deposits of the Colorado Plateaus, the Wyoming basins, and the Gulf Coastal Plain of Texas. Marine phosphorite deposits in central Elorida, the western United States, and other areas contain low grade uranium having 30—150 ppm U that can be recovered as a by-product from wet-process phosphoric acid. Because of relatively low uranium prices, on the order of 20.67/kg U (19), in situ leach and by-product plants accounted for 76% of total uranium production in 1992 (20). 

Sandstone The tertiary, Jurassic and Triassic sandstones of the western Cordillera of the United States account for most of the uranium production in that country. Cretaceous and Permian sandstones are important host rocks in Argentina. Other important deposits are found in carboniferous deltaic sandstones in Niger in Permian Lacustrine siltstones in France and in Permian sandstones of the Alpine region. The deposits in Precambrian marginal marine sandstones in Gabon have also been classified as sandstone deposits. 

Nilsen, T. H., 1982, Alluvial Fan Deposits In Sandstone Depositional Environments (edited by P. A. Scholle and D. Spearing), American Association of Petroleum Geologists, Memoir No. 31, Tulsa, OK, pp. 49-86. 

The Athabasca sedimentary Basin consists of Helikian polycyclic, mature fluvial to marine quartz-rich sandstone deposited in a near-shore shallow shelf environment (Ramaekers 1990) with an estimated filling beginning at about 1700 to 1750 Ma (Armstrong Ramaekers 1985). The estimate maximum thickness of the basin was 5 to 6 km from fluid inclusion studies (Pagel 1975). 

Unconformity-related deposits are found near principal unconformities. Examples include the ore bodies at Quff Lake, Key Lake, and Rabbit Lake in northern Saskatchewan, Canada, and in the Alligator Rivers area in northern Australia. Sandstone deposits are contained in rocks that were deposited under fluvial or marginal marine conditions. The host rocks nearly always contain pyrite and organic plant matter. The sediments are commonly associated with tuffs. Unoxidized deposits of this type consist of pitchblende and coffinite in arkasoic and quartzitic sandstones. Upon weathering, secondary minerals such as camotite, tuyamunite, and uranophane are formed. More information on these and other uranium deposit types is available (1). 

Farnand, J.R. and Puddington, I.E., Oil-phase agglomeration of germanium bearing vitrain coal in a shaly sandstone deposit, C.I.M. (Can. Inst. Mining Met.) Bull., 62 (1969) 267-271. 

These deposits are the largest known tar sand, or perhaps more appropriately, bituminous sandstone deposits in the United States. The presence of such a large percentage of organic material that can only be... 

Reservoir rocks and seals work together to form a trap for petroleum. Typical traps for petroleum include hills shaped like upside-down bowls below the surface of the earth, known as anticlines, or traps formed by faults. Abrupt changes in rock type can form good traps, such as sandstone deposits next to shale deposits, especially if a sand deposit is encased in a rock that is sufficiently rich in organic matter to act as a petroleum source and endowed with the properties of a good seal. 

Oil Sand A sandstone deposit that contains bitumen. Also referred to as Tar Sand. 

Although the number of samples analyzed is limited, the inescapable conclusion to be drawn from our data is that some of the Nile silt formations can be differentiated on the basis of trace element contents and REE distribution patterns. In addition, we conclude that the Early Predynastic (Amratian) pottery was made from clays found in the immediate vicinity of the kiln. Older shales that are found layered with the much earlier sandstone deposits that were cut by the Great Wadi were also analyzed. The REE patterns as well as the scandium, chromium, and iron concentrations are different enough to suggest that these materials were not used to produce pottery (21), In a previous paper, we discussed the possibility that some of this shale, or the white salt found associated with it (anhydrite-CaSOj, was mixed with the local clay to produce the finer, harder plum red ware (21). This addition could account for the slight difference in the average composition of the sherds from localities 11, 39, and 59 and the Masmas silt. 

The tar sands situated in Alberta consist of oil-bearing sandstones. Surface exposures occur in parts of the Athabasca deposit, but much of the deposit lies 100 m or more beneath the surface. Oil present in these Lower Cretaceous sandstone deposits is very viscous, thick, and partially oxidized so that it cannot be recovered by pumping alone. Hence, the term tar or bitumen describes this heavy oil fraction, which averages about 12% ranging up to as much as 18% of the deposit by weight. Deposits with less than 2-3% bitumen are excluded from the reserve data given in Table 17.4. 

For this test, the target layer was SIlL" , a lacustrine deltaic sandstone deposition. In a pilot area, 10 producers and 6 injectors were drilled in five-spot patterns, as shown in Figure 13.48. The distance between injector and producer was 200 m. The pilot area had been waterflooded for 20 years and then flooded by water-altemate-gas (WAG) for another 5 years. Before the ASPF flooding, the recovery factor was 49.9%. Some of the reservoir and fluid data for this test are shown in Table 13.17. 

We can not immediately conclude that we are seeing evidence for nuclear reactions. This variability was recognized years ago within the A.E.C. and it has been hypothesized that the New Mexico effect is due to chemical exchange in the oxidation-reduction cycles which are largely responsible for the formation of the large sandstone deposits of uranium in the Colorado Plateau. Now... 

Oil sands are unconsolidated sandstone deposits of a very heavy hydrocarbon bitumen. Bitumen is chemically similar to conventional oil but has comparatively high density (low gravity per American Petroleum Institute standards) and high viscosity. Based on United Nations Institute for Training and Research discussions aimed at establishing definitions for heavy crude oil and oil (tar) sands (1-3), bitumen can be placed in the context of other crude oils as shown in Table I. 

Ahlbrandt, T. S. Fryberger, S. G. 1982. Introduction to eolian deposits in sandstone depositional environments. In Scholle, P. A. Spearing, D. (eds) Sandstone Depositional Environments. American Association of Petroleum Geologists, Memoir, 31, 11-47. 

The United States is the largest producer of industrial sand in the world. The states of West Virginia, California, Illinois, Peimsylvania, Ohio, and New Jersey supply about 80% of all the high-quality silica sand used domestically. In Illinois and Missouri, practically all the glass-grade silica is derived from the St. Peter sandstone formation. Other quality deposits are the Oriskany sandstone deposits in West Virginia and Peimsylvania. Deposits are usually found in dune forms or in deposits lying 20-30 m under layers of silts, clays, and shales. 

The use of such lanthanide patterns to distinguish between ancient tectonic environments of sandstone deposition (e.g. Bhatia 1985) is seductive but premature for the following reasons ... 

Coffinite U(SiO, )j (OH),j is a black mineral, important as a uranium ore. It occurs in sandstone deposits and hydrothermal veins. 

Most of the major sandstone deposits are Mesozoic and Caenozoic. This is doubtless because rocks of this age contain the great piles of continental and marginal marine sandstones and the required periods ofweathering and erosion. Most of the uranium introduced to Palaeozoic marine basins yielded little better than weakly mineralized black shales because of the lack of an efficient concentrating mechanism. 

A consideration of other elements associated with roll-front deposits improves the accuracy and confidence in locating favourable trends (Fig. 9). Sulphate concentration and conductivity increase toward the redox front and then decrease abruptly owing to precipitation of iron sulphide, followed by calcium carbonate. High values of bicarbonate and selenium also contribute to identification of the zone of uranium mobilization on the oxidized side of the front. Molybdenum concentrations are normally associated with sandstone deposits, but haloes in the groundwater may be to the side of or farther down-dip than the centre of the geochemical cell. Arsenic is most valuable for its regional halo around areas of mineralization. 

It may come as a surprise that, when groundwater can be sampled, there is a remarkable similarity between the geochemical model described for sandstone deposits and the geochemistry of vein-like deposits. When the mineralization lies near the groundwater-table, water sampled on a scale of kilometres gives similar results for these two diverse cases in uranium, molybdenum, arsenic, radon, helium, sulphate, total dissolved solids, pH and alkalinity. 

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