Geological deposition

Class Geologic deposit type Cr202 composition, wt % Cr Fe ratios Principal use... 

The Columbia River system was characterized by lead inputs from natural geologic deposits, industrial effluents, and the mining and smelting of lead. 

Bitumen The collective mass of organic matter represented by the petroleum and asphalt in a geologic deposit. 

Clayton RN, Epstein S (1958) The relationship between 0/ 0 ratios in coexisting quartz, carbonate and iron oxides from various geological deposits. J Geol 66 352-373 Clayton RN, Kieffer SW (1991) Oxygen isotope thermometer calibrations. In Taylor HP, O Neil JR, Kaplan IR (eds.) Stable isotope geochemistry A tribute to Sam Epstein. Geochem Soc Spec Publ 3 3-10... 

Only a few metals—gold and platinum are two examples—appear in nature in metallic form. Deposits of these natural metals, also known as native metals, are quite rare. For the most part, metals are found in nature as chemical compounds. Iron, for example, is most frequently found as iron oxide, Fe203, and copper is found as chalcopyrite, CuFeS2. Geologic deposits containing relatively high concentrations of metal-containing compounds are called ores. 

Ore A geologic deposit containing relatively high concentrations of one or more metal-containing compounds. 

Barium is present at very low concentrations in most environmental samples. Thus, in spite of the availability of a detection limit of only a few ng ml 1 by flame AES, the element is rarely determined by flame methods AAS with electrothermal atomization or ICP-AES is more commonly used. A notable exception is in the determination of the element in barium-rich geological deposits.8 Another exception is in the analysis of formation waters from offshore oil wells.9 However, in this matrix, inter-element interferences are encountered from alkali and alkali-earth elements. These could be effectively eliminated by the addition of 5 g 1 1 magnesium and 3 g 1 1 sodium as a modifier.9... 

Seismic explosives produce the pressure impact during seismic measurements, which are carried out in prospecting for geological deposits, particularly oil horizons. Such explosives must detonate even under high hydrostatic pressures. 

Amino acid racemization dating of mollusc shell has not been investigated as extensively as that of fossil bone. Recently several studies have used d/l enantiomeric ratios to resolve stratigraphic relationships (24) and to date geological deposits by the calibration procedure (19,20). Racemization dating has also been applied to midden shell from archaeological sites with limited success (20). 

Activation analysis is used to establish trace element gerprints of geologic deposits of native copper. By using the statistical techniques of discriminant analysis and K-means cluster analysis and the trace element concentrations in artifact copper, an assignment of probable geographic and(or) geologic source of the artifact raw material can be made. 

Our trace element data base now contains analyses of 586 samples of native copper from deposits throughout the world. However, the sample sources are skewed toward the northern United States, especially the Lake Superior region. Trace elements can be considered as those normally found in concentrations below 100 ppm (i.e., below the 0.01% normally used as the lower limit of standard rock and mineral analyses). Trace elements do not play a major part in the physicochemical reactions that take place in the formation of geologic deposits. They are either concentrated in or dispersed throughout rock, mineral, and ore deposits... 

The earliest geologic deposits used as mineral supplements for agricultural soils seem to be chalk and marl. The beneficial effects of these materials on crops were known to the Celts as early as 2500 B.P. The Romans, who learned this practice from the Greeks and Gauls, even classified various liming materials and recommended that one type be applied to grain and another to meadow. However, liming materials were used for nearly 20 centuries before the beneficial effects were shown to be mainly due to the neutralization of excess soil acidity. 

Although the nature of retorted shale certainly depends upon the nature of the geological deposit from which the raw oil shale was mined, it depends, to a large extent, also upon the retorting technology used to process the raw oil shale. The information presented in this paper is obtained from the Paraho Oil Shale Demonstration carried out from 1973 to 1976 Cl). 

The extraction of construction materials (building stone, marble, lime) from geological deposits, disrupting the physical forms of landscapes and destroying... 

Option (c) is the main route considered for high level wastes from reprocessing. Because of its importance it is discussed in greater detail in a separate subsection ( 21.12). Geologic deposition is also the main choice for unreprocessed spent fuel elements. 

The solidification of HLLW, followed by geologic deposition, is piesaatly considered as the only realistic technique to create conditions for a safe long term disposal of HAW. The objectives of solidification is to immobilize the radioactive elem ts and to reduce the volume to be stored. The solidified product must be nondispersable (i.e. not finely divided as a powder), insoluble, and chemically inert to the storage environment, be thermally stable, have good heat conductance (this determines the maximum radioactivity and volume of the final product), be stable against radiation (up to 10 Gy), and have mechanical and structural stability. 

---