论长江中下游地区含铜黄铁矿型矿床成因

THE GENESIS OF CUPRIFEROUS PYRITE DEPOSITS,MIDDLE-LOWER YANGTZE AREA, EAST CHINA

本义从产于石炭纪地层小的含银黄铁矿矿床的土要地质特征、侵入岩与成矿关系以及稳定冈位索特征等人面的研究提出，该类矿床具有明显的沉积特征；成矿元素流主要来自石炭纪海水，成矿金属元素主要来自下优地层，成矿流体以大气降水为主，成矿热动力主要是岩石中积累的热能和穿切地壳易透区下面而来的热能（包括海西期火山活动所形成的地热场）；矿床属海底喷气（热水）沉积成国．燕山期侵入岩对其有不同程度的叠加改造。同时阐述了该类矿床的成因机制。

The Middle-Lower Yangtze area is an importunt Cu-Fe multimetal mecallogenic belt in China.The Carboniferous cupriferuus pyrite deposits are of the must magnificent types. Their reserve is about 33. 9 % of that of the whole regiun, and they also assuciate with remarkable guld. However,their genesis is still in dispute.It is showed that the ore-bodies are evidentally controlled by the lithufacies, Iithulugical charactes, and paleogeographic envirunnlent. The urebodies which are in the shapes uf stratifurm and stratoidform hosted in the borders between the clastic rucks and carbonate rucks of Luwer Huanglong Group, Upper Carboniferuus System. The ure-bearing rock formations are mainly the fine clastic rucks-cupriferuus pyrite ure beds-dolomite rucks- limestone. There are stratifurm bands uf volcani clastic ruck, lava and tuffaceous siltstone in sume ure-bearing furmations. The ure depusits general ly lucated in these parts where the depusitional environment changes abruptly, such as the edges of ancient basin ur subaqueuus upheaval. The structure and texture of ure evidentally furmed during the depositional and diagenetic process. In most ore districts, there are vein, veinlet, dissemmated and brecciated cupPer metallization in the underlying strata of stratiform urebodies. The intrusions of Yanshanian granitic rocks not only cut and melted the stratiform cupriferous pyrite ure bodies,but alsu refurmed the type, structure , texture, and mmeral facies of ore.The sulfur uf sulfides in the stratifurm ore budies originated mostly from the Carboniferous Oceanic water, minorly from the strata and magma. The lead mainly came from upper strata. The ore-forming fluids are the meteoric water and interlayer water, but some oceanic water and magmatic water are also mixed. The ore-forming metallic elements are mainly the origin of underlying strata.It is cuncluded that the Carbuniferous cuptiferous pyrite deposits in Middle-Lower Yangtxe areaare the exhalation deposits, and the Yanshanian granitic intrusion re formed them in different degrees too.