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87Sr/86Sr, 8 D and δ180 together with chemistry of oilfield brines, were measured from Cambrian to Neogene strata in the Kuqa Foreland Basin, northwest China. The brines have 87Sr/86Sr ratios ranging from 0.70944 to 0.71716, 8D values from -33‰ to -67‰ and δ18O from -9.0‰ to 3.9‰. The most radiogenic 87Sr brines have relatively heavy δ18O in the Cambro- Ordo-vician carbonates, and are suggested to originate from crystalline basement. 8 D and δ18O sys-tematics show that all the brines slope to Global Meteoric Water Line, and intersect at 8 D = -60‰ and δ18O = -8.8‰, close to that of present-day local meteoric water, suggesting that meteoric water has mixed with evaporated ancient meteoric water. More saline samples have the lowest δD and δ180 contents and molar Na/CI ratios of more than 0.9, resulting from salt dissolution.
87Sr / 86Sr, 8D and δ180 together with chemistry of oilfield brines, were measured from Cambrian to Neogene strata in the Kuqa Foreland Basin, northwest China. The brines have 87Sr / 86Sr ratios ranging from 0.70944 to 0.71716, 8D values from -33% o to -67 ‰ and δ18O from -9.0 ‰ to 3.9 ‰. The most radiogenic 87Sr brines have Comparative Heavy δ 18O in the Cambro-Ordo-vician carbonates, and are suggested to originate from crystalline basement. 8 D and δ18O sys-tematics show that all the brines slope to Global Meteoric Water Line, and intersect at 8 D = -60 ‰ and δ18O = -8.8 ‰, close to that present-day local meteoric water, suggesting that meteoric water has mixed with evaporated ancient meteoric water. More saline samples have the lowest δD and δ180 contents and molar Na / CI ratios of more than 0.9, resulting from salt dissolution.