Shale average

Element Average igneous rock Average shale Average sandstone Average limestone Average sediment... 

Post-Arehean average Australian shale average of 23 post-Archean shales from Australia (Nance and Taylor 1976, Taylor and McLennan 1985). 

In the Vastergotland and Narke provinces of Sweden, however, the Alum shales (average 70 ppm U) present a 2- to 3-m thick horizon (Fig. 3) enriched in uranium, probably by a diagenetic process, to an average of some 300ppm U. These shales are of Middle and Upper Cambrian plus Tremadoc age, and. have a thickness of several tens of metres. 

Average analytical data on the sedimentary rocks are compared with NASC (North American Shale Composite Grometet al., 1984) in Fig. 1.154. 

Analytical data on minor element contents are compared with Average Shale by Turekian (1972) (Fig. 1.155). 

Average contents of minor elements of the Onnagawa are mostly lower than Average Shale. However, Cu, Zn, Mo, Ba and U contents are anomalously high compared with Average Shale. 

All these comparisons support the hypothesis of an increase. The arithmetic means and thereby the collective doses seem to have increased by about a factor of four to six. If the aerated concrete based on alum-shale had not been used, the country-wide average has been estimated to be 30 % lower (Swedjemark 1985). 

The kerogen content of different oil shales, i.e., the average yield of oil of an oil shale can vary greatly. Most oil shales have oil yields between 50 and 150 1 oil/t oil shale, rich shales may even yield more than 200 1/t. A particular characteristic of oil shale is its high areal density, which can exceed 1 million b/acre at its thickest (Bunger et al., 2004). Oil shale can also be used directly as fuel for electricity generation, as, for instance, in Estonia. However, oil shale is characterised by a low calorific value between 7.5 and 9 MJ/kg (based on LHV), which is about one fifth of the energy content of crude oil (Porath, 1999). 

Properties and extraction processes Tight-formation gas is natural gas trapped in low-porosity (7 to 12%), low-permeability reservoirs with an average in-situ permeability of less than 0.1 millidarcy (mD), regardless of the type of the reservoir rock tight gas usually comprises gas from tight sands (i.e., from sandstone or limestone reservoirs) and shale gas. Sometimes tight gas also comprises natural gas from coal and deep gas from reservoirs below 4500 m. Shale gas is produced from reservoirs predominantly composed of shale rather than from more conventional sandstone or limestone reservoirs a particularity of shale gas is that gas shales are often... 

Table 18.1 Average Compositions of the Earth s Upper Continental Crust, Shale, Iron-Manganese Oxides, Phosphorite, and Various Types of Marine Sediments (All in Units of ppm. Unless Noted otherwise), along with Seawater and a Hydrothermal Vent Solution from the East Pacific Rise (both in Units of 10 g L ). 

Considerable geographic variability exists in the distribution of the source rocks contributing salts to river and groundwaters. As shown in Table 21.3, most of the evaporites, which are the dominant natural source of Na and Cl in river water, lie in marginal and endorheic (internal) seas. Some of these subsurfece evaporite deposits dissolve into groundwaters, which eventually carry Na and Cl into the ocean. Carbonates are the prevalent rock type between 15°N and 65°N. Precambrian-age crustal rocks and meta-morphic minerals predominate between 25°S and 15°N and north of 55°N. Shales and sandstones represent on average 16% of the terrestrial surfece lithology. 

Trenches excavated across the veins are typically flooded by surface water however, three partially flooded trenches have exposed bedrock. From small (< 5m ) outcrops exposed in three of the trenches, it is apparent that the average grain size of the clastic sedimentary rocks and the abundance of coarse-grained detritus, increases from NE to SW away from the buried Caradocian shale, with arkosic sandstone most abundant in the SW near the Christopher vein. An extensive array of 98 drill holes provides excellent downhole, 3-D control on our understanding of the geology. 

Very little information regarding the release of individual isomers was located in the literature. A coal liquefaction waste water effluent contained o- cresol at a concentration of 586 mg/L (Fedorak and Hrudey 1986). o-Cresol was detected at an average concentration of 1.1 pg/L for three samples of retort water from a shale oil production facility (Hawthorne and Sievers 1984). 

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