川东地区锶矿床地质特征及成因探讨

川东是我国锶矿资源远景最大，质量最佳的成矿区。铝矿产于下三叠统嘉陵江组二、四段的灰岩－白云岩－天青石膏质藻层纹白云岩－石膏岩（或灰岩）韵律层中。天青石膏质藻层纹白云岩是含矿层。准同生阶段已有天青石沉积，局部富集形成矿源层。在后生阶段的热力、压力驱动下．四川盆地的热卤水（２２０～３００℃）沿含矿层交代形成条纹条带状天青石矿层；第二期热卤水（１５０～２２０℃）在含矿层及其附近的碳酸盐岩裂隙中充填交代，形成四块状、脉状天青石；第三期热卤水（＜１５０℃）沿断裂充填形成天青石、重晶石脉。一、二期热卤水成矿作用常相互叠加，形成工业矿床。川东褶皱带西部背料部位具良好的找矿前景。

GEOLOGY AND GENESIS OF THE SR DEPOSITS IN EAST SICHUAN

Abstract As one of Sr - metallogenic provinces in China, the East Sichuan region is known for the largest prospective reserve and the best quality of all its kinds. The Sr deposits in the region are associated with a rhythmic sequence of limestone-dolomite -celestitic algal dolomite -gypsium rock in the 2nd and,gypsiferous, 4th members of the Lower Triassic, gypsiferous, Jialingjiang formation. The celestitic algal dolomite at the end of the rhythm is usually referred to a mineralization bed where celestite had begun precipitating ever since the penecontemporanious Period and later locally enriched into asource bed.By the epigenic period,the mineralization bed was replaced and modified by the hot brines of three different sphases from Sichuan basin to respectively yield:metasomatic streaky and bandy celestite deposits at 220-300℃ along itself around the axial parts of dome anticlines, infilling and replacement dePOsits with lumpy,veinlike celestite at 150-200℃ through its fissures and the nearby carbonates,and infilling celestite - barite veins at less than 150℃ through the adjacent faults.However, the 1st and 2nd sphase mineralizations had to be superposed before industrial deposits could be developed. Such a superposition is common for the anticlinal structures west of the East Sichuan folded belt so that they have brignt perspective of propecting for this resource.