| 东川式层状铜矿的沉积-改造成因 |
| 点此下载全文 |
| 引用本文：.1989.On the “sedimentation-transformation” genesis of the dongchuan type stratiform copper deposits[J].Mineral Deposits,8(2):3~13 |
| Hits: 2605 |
| Download times: 1684 |
|
|
| 中文摘要:对于东川式层状铜矿的成因，前人多持“沉积-变质”观点。通过研究，本文提出“沉积-改造”成因的新认识。新观点认为，沉积阶段铜不是在落雪组富集，而是在因民组红层中富集。在成岩阶段或成岩后，沉积岩中的水分被裂谷的高热流所加热，并由于深断裂的减压作用所驱动而产生对流循环。这种盐度较高的热液能淋滤汲取因民组中的铜质，并在断裂带附近向上运移。当含铜热液上升到达落雪组底部时，便与那里由细菌还原的硫结合形成硫化物沉积，形成层状铜矿。这个由热液将因民组(矿源层)中的铜转移到过渡层和落雪组底部(赋矿层)中成矿的过程，就叫做“改造”作用，它既不同于成岩作用也不同于变质作用。本文由此总结了东川式层状铜矿的成矿模式为“红层预集一改造热液转移一藻白云岩成矿”。 |
| 中文关键词:东川式层状铜矿 藻叠层石 矿源层 热液对流循环 改造作用 硫化物分带 |
| |
| On the “sedimentation-transformation” genesis of the dongchuan type stratiform copper deposits |
|
|
| Abstract:The Dongchuan type copper deposits have long been studied and well reported because of their great economic significance. The present paper proposes a “sedimentation-transformation” origin for this type of deposits to replace the current “sedimentation-metamorphism” model which has been broadly accepted since 1970s. According to the new idea, orebodies were not directly deposited in Luoxue dolomite where they now occur. It is postulated that copper was preliminarily concentrated in Yinmin Formation by the deposition of terrestrial detritus from the underlying copper-rich volcanogenic strata. During or after diagenesis, copper in Yimin Formation was mobilized and leached by hydrothermal solution which was derived from the interstitial water of sedimerits, heated by high geothermal gradient of rift environment, and circulated through the strata of Luoxue and Yinmin Formations. As a resuIt, copper was transported from the source bed-Yinmin Formation-upward to Luoxue algae dolomite where sulfur was produced by the reduction of sulfates. The copper sulfides were thus formed through the replacement of initial sulfides by Cu-bearing solutions. This process, called “transformation”, is different from either diagenesis or metamorphism. The metallogenic model is summarized as “pre-gathering of copper in Yinmin red bed→transportation of copper by transformation solutions→ore-form ing at algae dolomite of Luoxue Formation”. |
| View Full Text View/Add Comment Download reader |
