Distribution of Al, Li and Na in granite pegmatite quartz from Evje-Iveland and Froland.
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(Forkortet) Distribution of Al, Li and Na in granite quartz, South-Norway was estimated by LA-HR-ICP-MS (Laser Ablation Inductively Coupled Plasama Mass Spectrometry) analysis of quartz at Monash University, Australia. The results are preliminary and remain to be confirmed at NGU with the analytical method that currently is under development. Therefore, the present conclusions are subject to the results obtained at NGU and accordingly should be evaluated conservatively. The average concentration of Al in quartz from 15 localities in the Evje Iveland area varies from < 19 to 164 ppm whereas the concentration of Li varies from < 4.6 to 28 ppm. In the Froland area the concentration of Al and Li at the four pegmatite localities included from this area is <19 and <4.6 respectively. The maximum concentration of structural bound Na may be approached from the empirical expression: [A1] = [Li] + [Na] in mol%. Accordingly, the concentration of Na in Froland is 1 ppm or less whereas Evje-Iveland features values between 0 and 46 ppm. Although only four pegmatites from Froland are incorporated in the present study, it is clear that all the pegmatites yielded low concentrations of impurities hence the quality of quartz from pegmatites in this area by far exceed the average quality obtained from Evje-Iveland. Only 2 out of 15 localities in Evje-Iveland (#94 and 95) yilded comparable low concentrations of Al, Li and Na. Granite pegmatites in Froland are also relatively large, compared to Evje-Iveland and are situated closer to the sea. Therefore, as a cautious preliminary conclusion, depending on the results from the NGU-lab, it is suggested to implement a detailed sampling program of selected Froland pegmatites comprising the desired tonnages.