摘要
采用构造岩石地层—沉积盆地—热水成矿流体及沉积组合—构造变形分析等方法 ,对秦岭造山带晚古生代伸展构造特征及意义进行了系统研究。结果表明 :秦岭造山带从加里东期末—海西期末一直处于 (剪切 )伸展体制下 ,形成一系列伸展构造 ,其伸展构造样式主要有同生断裂、剥离断层、陆表海域中的盆 -岛构造、地堑 -地垒式盆地构造、三级热水沉积成矿盆地 ,叠合沉积盆地内的伸展构造样式有褶叠层、分层剪切流变构造、滑塌同沉积构造、阶梯状同生断层等 ;这些伸展构造样式显示秦岭微板块是以伸展作用发生陆壳变形的 ,可称为秦岭型伸展构造样式 ;伸展构造是主要控矿构造 ,低序次同生断裂是含矿热水运移的通道 ,三级热水沉积成矿盆地是聚矿空间和热水沉积成矿场所 ,热水喷溢通道口及含矿热水沉积岩相是矿层赋存的部位。认为秦岭型伸展构造样式对研究区域成矿学和区内的矿产资源勘查与预测有重要的理论和应用价值。
A series of extensional structures were formed in the environment of shearing extension of the Continental Crust from the end of the Caledonian to the Early Indo Chinese in the Qinling orogenic belts. Patterns of extensional tectonics or the Qinling extensional pattern include synsedimentary faults, detachment faults, basin island in the continental sea, horst graben typed basin, subbasin of hydrothermal water. Patterns of extensional structures of superimposed basins include cascade fold layers, structure of layering shear deformations, slumping synsedimentary structure, step synsedimentary faults. These patterns of extensional structures suggested that deformations of the Qinling continental block with special continental dynamics had been undergone shearing extension. Extensional structures were dominant structure controlling ore depositions, i.e. passing way for hydrothermal waters bearing ore materials was synsedimentary faults while space and room for ore deposition and accumulation of hydrothermal waters were subbasins of hydrothermal waters, and signatures for ore layer existing were vents of the hydrothermal plume and rock facies. Research on extensional structures in the area can help us well understand the regional metallogenic and prospecting mineral deposits.
出处
《西北大学学报(自然科学版)》
CAS
CSCD
北大核心
2001年第3期235-240,共6页
Journal of Northwest University(Natural Science Edition)
基金
国家重大基础研究规划项目 (G19990 432 0 0 )
国家自然科学基金 (4 9732 0 80 )联合资助项目