论文部分内容阅读
伊通新生代玄武岩中存在3种不同成因的捕虏体,其中上地幔岩浆分异结晶形成的辉石岩捕虏体中尖晶石具有独特的成分分带。电子探针分析显示在尖晶石矿物的边缘富Al,而贫Mg、Fe和Cr,矿物中心富Mg、Fe和Cr,而贫Al,从中心向两侧基本对称。从尖晶石成分分带的元素分布特征判断,其形成不是固溶体相平衡过程中的离子扩散,而可能是化学平衡过程中结晶矿物与熔浆之间化学成分平衡的结果,属于化学平衡导致的成分分带。从尖晶石矿物中心到边缘的温度变化不能反映矿物形成后所经历的温度变化状况,与尖晶石共生矿物的二辉石地质温度计所能代表的地质意义是矿物中心的温度(~1 006℃),反映矿物开始结晶时的温度状态。
There are three different types of xenoliths in the Yitong Cenozoic basalts, of which the spinel of pyroxenite xenoliths formed by differentiation of upper mantle magma has a unique component zoning. Electron probe analysis shows that the spinel minerals are rich in Al on the edges and Mg, Fe and Cr on the edge of the spinel. The mineral centers are rich in Mg, Fe and Cr, while Al is lean, and symmetrical from the center to both sides. Judging from the elemental distribution characteristics of the spinel zonation, the formation is not the ion diffusion in the phase equilibrium of solid solution, but may be the result of the chemical balance between the crystalline mineral and the molten metal in the chemical equilibrium process, which belongs to the chemical equilibrium Ingredient banding. The temperature change from the spinel to the edge does not reflect the temperature change experienced by the mineral. The geological meaning represented by the pyroxene geothermometer with the spinel symbiotic mineral is the temperature at the center of the mineral (~ 1006 ℃), reflecting the temperature of the crystals began to crystallize state.