Granite measured

In the granite and alum shale areas, exhalation measurements above the ground were well correlated with the indoor air measurements. In the esker area, the exhalation rates were normal, and the high indoor Rn-222 concentrations here are believed to be caused by convective flew due to underpresure in the houses. (Stranden et al, 1985). 

The highest indoor Rn-226 concentrations occur in areas with alum shale in the ground. Measurements in these areas yield a good agreement between exhalation rates and indoor Rn-222 concentrations. Even in granite areas, high indoor Rn-222 concentrations may occur, but no extreme values were found in such areas. These findings are also confirmed by the field studies. 

The extent to which isotopic fractionation occurs at sub-1000°C temperatures in magmatic and regional metamorphic systems is unstudied in detail, but limited natural and experimental data in granitic systems suggest that measurable fractionation may occur under these conditions. This fractionation might be applied in studies of magmatic and ore evolution, either for thermometry or mineral deposit exploration. 

Figure 4. Radiogenic Ca enrichments measured on whole rocks as reported hy Marshall and DePaolo (1989), shown here as 8c, values with 1-sigma uncertainties and plotted versus (a) K/Ca and (h) Enj value. The inferred value for seawater is also plotted in (a). Mid-ocean ridge basalts have no measurable enrichment of Ca/ Ca relative to the initial value for the Earth (151.016), as expected for magma derived from the Earth s mantle. Many granitic rocks, especially those with high K contents and low e j values, have significantly elevated Ec, values.

Rhenium abundance in most rocks is measured in parts per billion or less and minerals in which it is a major constituent are rare. It is similar geochemically to molybdenum, which it commonly accompanies through magmatic and related hydrothermal stages, and is concentrated in molybdenite associated with various types of granite-related deposits. Molybdenites with some of the highest concentrations of rhenium are associated with porphyry Cu and Cu-Au deposits, which are the primary industrial source of rhenium. Rhenium can also be concentrated by low-temperature... 

Figure 6.11 RSCs measured by LA-ICP-MS for three geological reference materials, granite NIM-G, lujavrite NIM-L and syenite NIM-S, from the National Institute for Metallurgy, South Africa.

Figure 9.48 Correlation of halogen concentration measured in sediments and rock samples by isotope dilution LA-ICP-MS using a high ablation system UNA-Spark n -Atomizer and double-focusing sector-field / -MS Element 2 with the indicative values 59 Samples SRM 2704 (Buffalo River Sediment), SRM 1646 (Estuarine Sediment), Granite GS-N, Bauxite BX-N and Disthene DT-N. (S. Boulyga and K. G. Heumann, Int. ). Mass Spectrom., 242, 291 (2005). Reproduced by permission of Elsevier.)...

Measurements were also performed (with Cs, Sr and Am) on granite particles of various surface to volume ratios which would give some qualitative information on the sorption mechanisms involved. 

Measured mass related distribution coefficients for granite... 

Measurements on granite from other locations have given higher values (up to -0.2)... 

Measurements on silt taken from a natural crack in granite gave the values -0.7 for Cs, -1.7 for Sr and 1.2 for Am... 

Retention in the Hostrock. For granite, apparent surface to mass ratios of about 3 m /kg for Cs, 2 m /kg for divalent elements and <10 m /kg for tri- and tetravalent elements have been estimated, based on Kd/Ka-measurements on Cs, Sr and Am on granitic macro surfaces (1,31). Retention factors are given in Table IX, as generated from measured K.-values (from Table V), assuming long contact time, non-oxidizing conditions and representative fracture and permeability data for the rock (p. 

In previous work (l.> > ) it was found that the kinetics of sorption was an important parameter affecting the migration of nuclides in geologic media. For example, in experiments designed to measure the kinetics of reaction for radionuclides in solution with tablets of rock, it was found that periods from several minutes to several hours were required for the radionuclides to reach steady state concentrations on the rock tablets and in the solutions. Figure 1 shows the reaction curves found for the sorption of plutonium and americium from solution by a tablet of granite. The reaction rates for the sorption of plutonium and americium from solution are not the same, and both require a number of hours to reach steady state concentrations. 

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