吴川-四会断裂带大王山花岗岩早期韧性变形特征

大王山剪切带内出现一系列规模不等的糜棱岩条带,广泛发育S面理和C面理,还出现一系列次级拉伸折劈理、剪切条带和不对称小褶纹。剪切带中的石英、云母等基质矿物以塑性变形为主,出现动态重结晶、亚晶、波状消光等显微构造。长石主要以破裂和香肠化为主,出现粒内的张裂隙和肿缩构造。石英和长石存在明显的流变学差异。通过构造和显微构造特征判定,大王山剪切带为右旋剪切带。吴川-四会断裂曾经历过右旋韧性剪切作用。     

Control of relay structure on mineralization of sedimentary-exhalative ore deposit in growth faults of graben systems

Abstract: Based on the study of ore deposits and orebody structures of two sedimentary-exhalative ore deposits,i.e. , Changba and Xitieshan Ore Deposits, it is found that the structural patterns of metallogenic basin of seaftoor exhalative sulfide deposits in the ancient graben systems are controlled by relay structures in normal faults. The shapes of metallogenic basins are composed of tilting ramp, fault-tip ramp and relay ramp, which dominate migration of gravity current of ore-hosted fluid and shape of orebody sedimentary fan in the ramp. By measuring and comparing the difference of length-to-thickness ratios of orebody sedimentary fan, the result shows that the occurrence of the ramp has a remarkable impact on the shape of orebody.     

云南东川金沙江变质杂岩的地球化学特征

分析了东川金沙江杂岩的稀土元素和同位素地球化学特征,稀土元素Ｔｂ,Ｔｍ异常值很低,表明杂岩物质来源较深。变质辉长岩（斜长角闪岩）的Ｓｍ－Ｎｄ等时线年龄国（１３４６±６２）Ｍａ,εＮｄ＝５．９,揭示该区地幔在中元古晚期仍亏损地幔,有别于东川矿区,可能为一局部的隆起带,碱长正长岩的侵入围岩是条带状大理岩,石榴子石云母片岩,变钠质火山岩,其岩石类型与四川的河口群相似,推测围岩地层时代为早元古代,碱长正长     

一种新的金矿类型—剪切带型金矿

剪切带型金矿是受韧剪切带控制,并以剪切作用为主要成矿机制的金矿床,近年来已逐渐被认识为一种新类型金矿.广东河台金矿是剪切带糜棱岩类型金矿的典型,而新洲金矿则是推覆剪切带型金矿的代表.     

甘肃白银厂矿区小型构造的磁组构分析

岩石标本磁各向异性的统计检验准则适用X~2检验。矿区岩石的磁组构与岩石组构及有限应变形态组构具有相同的极密优选组构特征。磁面理平行于矿区第一期劈理,也平行于应变椭球最大拉长轴面;磁线理与拉长线理近于平行。磁化率椭球与应变椭球具有共轴性,二者的两半轴比存在函数关系。