广西花山航空伽马能谱特征及找矿预测          下载免费PDF全文

林曼曼  董根旺  李海明  王猛  宋洋洋  刘媛媛 《地质找矿论丛》2022,37(3):377-383

广西花山岩体为多期（次）侵位花岗岩体，在岩体内部具有良好的铀成矿地质条件。文章基于航空伽马能谱实测资料，对花山花岗岩体的放射性分布特征进行了研究。研究结果显示，花山岩体整体处于放射性偏高场-高场区域，岩体中心偏南部位的铀含量有明显增高趋势，望高单元的核部和华美单元具有明显的铀迁入特征，F参数高值区分布在望高单元的核部，根据元素的迁移富集规律，圈定出铀矿成矿的有利部位，为扩大华南地区铀矿勘探区域提供了地球物理基础资料。  相似文献   

东喜马拉雅构造结南迦巴瓦岩群花岗质片麻岩的初步研究   总被引：5，自引：0，他引：5  

孙志明  董瀚  廖光宇  郑来林  耿全如  楼雄英  李生  石文礼  张东 《沉积与特提斯地质》2005,25(4):1-10

野外地质填图和研究发现,东喜马拉雅构造结高喜马拉雅结晶岩系中有古老的花岗岩侵入,并在鲁霞地区圈定了9个花岗质侵入体。古老的花岗质岩石主要侵位于南迦巴瓦岩群直白岩组中,与南迦巴瓦岩群一起经历了麻粒岩相变质作用而形成花岗质片麻岩套。岩石类型有花岗闪长质片麻岩、黑云母花岗质片麻岩、闪长质片麻岩等。岩石化学研究表明这些花岗片麻岩套具“S”型特征,可能有深部幔源物质的加入。花岗岩形成深度在2～5km之间．侵位时代为552～525Ma,为新元古代晚期,属泛非期陆内演化阶段的产物。高喜马拉雅地区在元古宙末期形成了结晶基底。  相似文献   

U and Th Contents and Th/U Ratios of Zircon in Felsic and Mafic Magmatic Rocks: Improved Zircon-Melt Distribution Coefficients     

WANG Xiang  Williams L. GRIFFIN  CHEN Jie  HUANG Pinyun  LI Xiang 《《地质学报》英文版》2011,85(1):164-174

High-precision data on U and Th contents and Th/U ratios of zircon obtained using secondary ion mass spectrometry analysis have been collected from the literature. Zircon in the granitic rocks has median values of 350 ppm U, 140 ppm Th, and Th/U=0.52; the recommended zircon-melt partition coefficients are 81 for DU and 8.2 for DTh. In zircon from mafic and intermediate rocks, the median values are 270 ppm U, 170 ppm Th, and Th/U=0.81, and the recommended zircon-melt partition coefficients are 169 for DU and 59 for DTh. The U and Th contents and Th/U ratios of magmatic zircon are low when zircon crystallizes in equilibrium with the melt. Increasing magma temperature should promote higher Th contents relative to U contents, resulting in higher Th/U ratios for zircon in mafic to intermediate rocks than in granitic rocks. However, when zircon crystallizes in disequilibrium with the melt, U and Th are more easily able to enter the zircon lattice, and their contents and Th/U ratios depend mainly on the degree of disequilibrium. The behavior of U and Th in magmatic zircon can be used as a geochemical indicator to determine the origins and crystallization environments of magmatic zircon.  相似文献