摘要
根据对岩体产出的构造背景、区域地层、构造运动和岩石学、地球化学及同位素特征的分析,作者将大容山紫苏花岗岩归属于海西晚期—印支期同碰撞花岗岩。产出在华夏古陆与江南古陆碰撞对接带的西南端,钦州残余海盆中。成因上是硅铝质地壳部分熔融的产物,熔融程度为40～55％。熔融发生在低—中级麻粒岩相条件下,T=780°～1000℃,P=3.43～4.48kb,fO_2=10^(-12)～10^(-15)bar,fH_2O=1～1135bar。从东向西花岗岩浆有明显的演化趋势。但岩浆分异微弱不利于W、Sn和Cu的成矿。
According to the tectonical background of the rockbody occurrence regional strata, tectonical movement, petrology, geochemistry and the analysis of isotopic character, the authors think that Darongshan Charnockite is belonged to the synchronous collision gra-nite of late Hercynian-Indo-Chinese Epoch. It occurs at the southwest end of collision suture zone between Cathaysia and Jiangnan Old and. In the residual sea basin of Qin-zhou. It is the product of some part sialic crust melting in geneses, With 40-50% melting degree, and the melting took place at the condition of low-medlium grade granulite facies, T = 780-1000@, P = 3. 43 - 4. 48kb, fo2 = 10-12 - 10-1 5bar, fH2O= 1 -1135bar. There is an evident evolutional trend to granitic magma from east to west, but the differentiation of magma is too weak to benefit for the mineralization of W、Sn and Cu.
出处
《矿产与地质》
1990年第2期1-10,共10页
Mineral Resources and Geology
