新疆库车坳陷西段膏盐层沉积、 地球化学特征及找钾方向

库车坳陷西段深部(5141～5218 m埋深)已有古近纪固体钾石盐矿(化)层的发现,但对该区域的膏盐层特征及成钾条件、找钾方向仍需做进一步的系统研究.以油气钻井深部膏盐层岩屑为主要对象,对库车坳陷西段膏盐层的沉积、岩石学特征以及钾、溴氯系数、Sr和S同位素等地球化学特征进行研究,并对该区盐构造特征及演化进行分析.结果表...

Sedimentary-Geochemical Characteristics and Potash-Prospecting Potential of Gypsum-Salt Layer in Western Kuqa Depression

The Paleogene solid potassium salt mineralization has been found in the deep layer(5141-5218 m)of western Kuqa Depression,but it is still necessary to further study on the characteristics of gypsum-salt layer,potash conditions and potashprospecting in the region.Taking the gypsum-salt layer debris in deep oil and gas drillings as object,in this paperit performs research on sedimentary and petrological characteristics of gypsum-salt layer,as well as potassium content,bromine-chlorine coefficient,Sr and S isotopes and other characteristics in western Kuqa Depression.Besides in this paper it also analyzes the salt tectonic characteristics and evolution in the region.The results show that the potassium and bromine-chlorine coefficients are good in Quele-Yangta belt in the south of the Qiulitage tectonic zone,which proves to be a good condition for potash formation.Sedimentary characteristics of Kumugeliemu Group,potassium content,bromine-chlorine coefficient,Sr and S isotopic characteristics indicate the potential potassium formation in the Dabei area,north of the Qiulitage structure belt.Sedimentary characteristics of Kumugeliemu Group and the analysis of the salt structure evolution reveal that Quele-Yangta belt is a favorable secondary depression for potassium in the salt-forming period,which is better preserved in the later period.It is considered that Quele-Yangta belt which is located in the south of Qiulitage tectonic zone in the western Kuqa Depression is the most advantageous area for potassium exploration,besides,there are several potash prospecting areas in the north of Qiulitage,including Dabei district.