Fluid inclusion and isotopic constraints for fluid evolution in the Ordovician veins in Central Tarim, NW China
Barite, anhydrite, fluorite, calcite and quartz are found filling factures in Central Tarim. Modem brines have δ18O values from -1.5 to +1.4‰, and 87Sr/86Sr from 0.71026 to 0.71109. Hydrothermal barite veins show an average δ18O value of 12.0‰ and precipitated at～142℃ from a solution with a δ18O of～1.80‰ and a 87 Sr/86Sr of ～0.7090. Subsequently, the solution was cooled by mixing with meteoric water, resulting in a δ18O of- 1.60‰. Anhydrite and fluorite veins have lower homogenization temperatures and show much higher 87Sr/86Sr ratios (0.70912 to 0.71036) than barite and bulk limestone, but are closer in composition to modem brines, suggesting more radiogenic Sr contribution from clastic rocks in the west to the Central Tarim during cooling. Calcite veins were precipitated under a wide temperature range and show variable 87Sr/86Sr ratios.Quartz veins were likely not in oxygen isotopic equilibrium with the mineralizing fluid.
C.Cai K.Li H.Li G.Wu
Key Lab of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences,Beiji Tarim Oilfield Company, PetroChina, Kuerle, Xinjiang, P.R.China
国际会议
第十二届水-岩相互作用国际研讨会(P0roceedings of the 12th International Symposium on Water-Rock Interaction)
昆明
英文
703-707
2007-07-31（万方平台首次上网日期，不代表论文的发表时间）