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塔里木盆地寒武系底部黑色岩系是重要的海相烃源岩之一.对该岩系中11个主要组成岩石-硅质岩进行稀有气体同位素分析,柯坪地区硅质岩的R/Ra比值为0.032~0.319,40Ar/36Ar为338~430;库鲁克塔格硅质岩的R/Ra比值为0.44~10.21,40Ar/36Ar为360~765.从西部到东部,硅质岩中的R/Ra与40Ar/36Ar比值同步增长,二者呈现正相关关系,并从壳源区向幔源区演化.硅质岩中的过剩氩40ArE与R/Ra比值正相关,说明硅质岩中过剩氩与幔源氦的来源一致.西部和东部硅质岩的R/Ra比值对比显示,东部硅质岩形成于幔源流体驱动的海底热水流体活动系统,该区壳幔物质和能量的交换作用强烈,而西部硅质岩则是海底热水流体羽漂移到该处沉淀而成的,远离海底热水流体活动中心.另外,从硅质岩的稀有气体同位素异常可推知,寒武系底部黑色岩系形成的海洋缺氧事件可能与海底大规模的火山作用及其伴生的海底热水流体活动有直接的关系.
The Cambrian black rock series in the Tarim Basin are one of the most important marine source rocks. Rare gas isotopic analysis of eleven major component rocks and siliceous rocks in this series is carried out. The R / Ra The ratios of R / Ra of Kuluktage chert are 0.44 ~ 10.21 and the ratios of Ar / 36Ar are 360 ~ 765. From west to east, the ratio of R / The ratios of R / Ra to 40Ar / 36Ar increase in a synchronous manner, which shows a positive correlation between them, and evolves from the crust source region to the mantle source region. The excess argon 40ArE in the chert is positively correlated with the R / Ra ratio, consistent with excess argon mantle helium source. R silicalite the west and east / Ra display contrast ratio, Eastern silicalite formed in the sea water activity system mantle fluids fluid driven, the area of the shell mantle and energy Exchange is strong, while western siliceous rocks are the migrating submarine hot-water fluid feathers drifting away from the active hydrothermal fluid center of the seafloor.In addition, from the rare gas isotopic anomalies of the silicalite, it can be deduced that the Cambrian The marine anoxic event formed by the black rock series in the bottom may be related to the massive volcanism and associated seafloor heat Water fluid activities have a direct relationship.