鲁西新生代含蓝宝石玄武岩的成岩成矿模式

THE PETRODENIC-MINEROGENIC MODEL FOR CENOZOIC SAPPHIRE-BRARING BASALTS IN WEST SHANDONG

鲁西原生蓝宝石矿产于长期稳定的克拉通环境中。该区蓝宝石及含蓝宝石玄武岩浆的形成是多种地质作用的综合结果。方山碱性玄武岩浆在地幔深处曾发生蓝宝石的结晶作用,由于玄武岩浆携带蓝宝石以持续的高速度上升,致使蓝宝石在岩浆中保持准稳态,形成品位较高的蓝宝石原生矿;团山子含蓝宝石碱性玄武岩浆在整个岩浆上侵过程中表现为慢速上升,蓝宝石不能长期保持准稳态,导致蓝宝石被熔蚀、分解,甚至全部被其它矿物替代;二姑山、隋姑山碱性玄武岩浆本身不含蓝宝石,因此,无论岩浆以何种方式上侵,均不形成蓝宝石矿。

The sapphire deposit associated with Cenozoic volcanic rocks from》est Shandong is locatedwithin the long--stable cratonie environment. The sapphire and the sapphire- bearing basalticmagma were formed as a result of a series of geologicprocesses. There ocurred crystallization ofsapphires including other mineral assemblages existing in Fangshan evolved magma at the greatdepths. Because the magma carried sapphires and erupted at a high speed,so that the sapphiresshould be on the stable condition, the higher--grade primary sapphire deposit has been formed;Tuanshanzi evolved magma got to the surface in slow transit time or was detained on the way tothe surface,so the sapphires would be resorbed and all replaced even by other minerals; There wasno sapphire in the magmas of Ergushan and Suigushan alkali basalts, there, on matter in someway or other the magmas erupted,they could not form sapphire deposits.