摘要
华北太古宙大陆内2.3 Ga开始裂解的辽吉古元古代裂谷,于2.2～1.7 Ga期间完成拉伸裂陷、沉积堆积、底辟侵入、挤压褶皱、隆升拆离、逐渐消亡的全部演化过程.辽吉古裂谷的矿产丰富,其成矿作用与裂谷的地质演化紧密相关.裂谷拉张裂陷堆积阶段为成矿作用提供了成矿物源,在不同的古构造和古地理环境下形成不同的含矿建造(矿源层);裂谷构造体制转换的挤压造山阶段,在变质、变形、岩浆活动等构造热事件影响下,由不同矿源的物质基础或在不同的成矿就位场所,形成不同成因的矿床类型组合;在非造山岩浆活动阶段,岩浆和热液的作用可使某些矿床进一步富集.在裂谷演化结束稳定之后,由于中生代的濒西太平洋构造带横跨辽吉古裂谷,印支-燕山期的构造岩浆活动对裂谷的成矿作用不可忽视,古元古代的含矿建造或已形成的矿床都有不同程度的印支-燕山构造岩浆活动热事件的叠加改造.此外,印支-燕山构造岩浆活动也在早期成矿物质的基础上新生成一些金(银)矿床.
The Archean North China Craton began to split at - 2.3 Ga and shaped an intra-craton rift, named Liaoning-Jilin Paleoproterozoic rift. In a span of 2.2 - 1.7 Ga, this paleo-rift experienced such complicated growth history as stretching sink, volcano-sediment accumulation, diapir intrusion, buckle folding, uplift detachment till extinction. Liaoning-Jilin rift is rich in mineral resources that has closevy relation to the evolvement process. In the stage of stretching sink, abundance of volcano -sediment materials accumulated first as the source of the ores and formed different mineralizing formations （ore-source beds） in distinct tectonic and geographical setting. And then a series of ore emplacements occurred to form different types of ore deposits with various genesis under thermo-tectonic events of metamorphism, deformation and magmatism etc. The next ore-forming process was the mineral concen by hydro-thermal fluids in non-orogenic magma activity. During the Mesozoic,the Liaoning-Jilin palaeo-rift was in the structural belt on the brink of the western Pacific Ocean and influenced by the thermal event from the Indosinian - Yanshanian tectonic-magma activity, which increased the ore-forming and ore-concentration in the rift. Actually the Paleoproterozoic ore-forming formations or deposits in the rift were mostly overprinted or reconstructed by the Indosinian-Yanshanian thermo-tectonic event. Some gold （silver） deposits in the rift may be inseparable with the Indosinian-Yanshanian thermal-tectonic event.
出处
《地质调查与研究》
2005年第4期213-220,共8页
Geological Survey and Research
基金
地质大调查综合研究项目中国成矿体系与区域成矿评价(K1.4-3-1)
关键词
古元古代
辽吉古裂谷
地质演化
成矿作用
Paleoproterozoic
Liao - Jilin Paleoproterozoicrift
geological evolvement
mineralizing process
