成矿期构造应力场有限元数值模拟在成矿预测中的应用

Application of Metallogenic Epoch Tectonic Stress Field Finite Element Numerical Simulation on Metallogenic Prediction

山东招远前孙家和金华山两个金矿床,均位于前孙家—洼孙家断裂带南段。依据两个矿区的矿体分布及构造特征,确定了对成矿期构造应力场进行有限元数值模拟的条件:(1)成矿期最大主应力方向——前孙家金矿区为325°,金华山金矿区为5°;(2)三种岩性的岩石力学参数;(3)有限元划分——前孙家矿区396个单元、412个结点,金华山矿区400个单元、411个结点。利用构造应力场有限元数值模拟软件,得出两个矿区成矿期最大张应力分布图。结果显示,两个矿区的已知矿体基本与成矿期最大张应力场位置吻合。依据该成果推断出两个矿区还有3个新的未知矿体存在。

The Qiansunjia and Jinhuashan two gold mines in Zhaoyuan,Shandong are all situated in the south sector of Qiansunjia—Wasunjia faulted zone. According to their orebody distribution and structural features,ascertained conditions to carry out metallogenic epoch stress field finite element numerical simulation. They are:(1) maximum principal stress direction—Qiansunjia gold mine 325 o,Jinhuashan gold mine 5 o;(2) rock mechanics parameters of three lithologic types;(3) finite elements division—Qiansunjia gold mine396 elements,412 nodes and Jinhuashan gold mine 400 elements,411 nodes. Using tectonic stress field finite element numerical simulation software,worked out metallogenic epoch maximum tensile stress distribution map for the two gold mines. The result has shown that the known orebodies in the two mines are basically tally with the metallogenic epoch maximum tensile stress field positions. Based on the result has inferred out 3 new undiscovered orebodies in the two mines.