摘要
Culberson自然硫-重晶石矿床位于美国德克萨斯州的Delaware油气盆地中,是北美最大的自然硫矿床。它产在晚二叠世Ochoan期的Castile组和Salado组的石灰宕夹薄层蒸发岩和有机质灰岩中,重晶石和自然硫是后生的,常交代这两个组地层中的蒸发岩和富含有机质的灰岩,并填充在古喀斯特中。流体包裹体的研究表明：有两个世代的包裹体,即成岩时和方解石后生加大和重晶石中捕获的石油包裹体和流体包裹体。按包裹体的成分和相态可分为一相液体包裹体、二相气液体包裹体和油气包裹体。研究表明,在方解石、重晶石和天青石的同一生长带中可见到含有不同气液比的流体包裹体、空的包裹体和油气包裹体,它们是在一个不混溶的环境中捕获的,因而其均一温度的测定并不可靠。流体包裹体的T_e在-18℃～-24℃之间,属于NaCl- H_2O体系,盐度为2%～10%。有许多油气包裹体,因而其成矿流体应是一个温度小于100℃的油田水．
The Culberson sulfur-barite deposit is located in Culberson county, West Texas. Geologically, it is occurred in Delaware sedimentary, petroleum and natural gas basin. There are several sulfur-barite deposits occurring in the basin, Culberson is the largest one. Culberson deposit is hosted by Upper Permian Castile and Salado formation. The Castile and Salodo formation consist of limestone with thin layers of evaporate and organic materials. Natural sulfur and barite is formed post diagenesis, by filled into the paleo karst and replaced the internal layers of anhydrite. Two generation fluid inclusions are found： I. Fluid inclusion formed during the diagenesis, and II. fluid inclusion trapped during the authigenic calcite, barite overgrowth. According to the phases and composition at room temperature, the fluid inclusions could be divided into： one phase liquid inclusion; two phases vapor and liquid inclusion, and oil inclusion. In a same growth zone of calcite, several types of fluid inclusions, such as one phase liquid, different vapor/ liquid ratio inclusions and oil inclusions occurred. These inclusions are hardly to be used to get the temperature of homogenization, since they are formed in heterogeneous trapping or an immiscibility environment. The eutectic temperatures of fluid inclusions range from - 18 to -24°C, indicating the fluid belongs to a NaC1-H2O system, with the salinity ranges from 2% to 10%, and co-existing with the oil inclusions, these show that the ore forming fluid is an oil filed brine and with temperature less than 100°C.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第2期485-490,共6页
Acta Petrologica Sinica
关键词
自然硫
重晶石
流体包裹体
后生加大
油田水
Natural sulfur
Barite
Fluid inclusion
Authigenic overgrowth
Oil field brine
