| 川西呷村黑矿型矿床含矿火山岩系热液蚀变与物质-化学变化 |
| |
| 引用本文： | 侯增谦,T Urabe.川西呷村黑矿型矿床含矿火山岩系热液蚀变与物质-化学变化[J].矿床地质,1996,15(2):97-108. |
| |
| 作者姓名： | 侯增谦 T Urabe |
| |
| 作者单位： | 中国地质科学院矿床地质研究所 |
| |
| 基金项目： | 日本国际产业技术研究事业基金 |
| |
| 摘 要： | 川西呷村黑矿型矿床产于酸性流纹质火山岩系上部。矿区蚀变可分为矿化热液蚀变和区域低温蚀变，后者广布矿区；前者绕网脉矿（硅矿）形成蚀变岩筒，并具明显的蚀变分带：自内而外由石英－钡冰长石带向绢云母－石英带递变，自下而上由绿泥石带向石英－绢云母带递进。采用“惰性”微量元素方法恢复了含矿岩系原岩成分，定量估算了蚀变引起的物质－化学变化。在蚀变岩筒中，Ｃｕ、Ｐｂ、Ｚｎ强烈富集，远离蚀变岩筒，Ｃｕ略有亏损，Ｐｂ
|
| 关 键 词： | 火山岩 热液蚀变 含矿 黑矿型矿床 物质变化 |
Hydrothermal alteration of ore-bearing volcanic rocks and mass chemical CHANGE in the Gacun kuroko-type deposit, weatern Sichuan |
| |
| Abstract: | The Gacun kuroko-type deposit in western Sichuan is distributed in the inter-arc rift zone within the Triassic Yidun island arc and occurs in the upper part of the thyolitic volcanic rocks in bimodal suite. Alterations in the ore district include mineralizing hydrothermal alteration and regional low-temperature alteration. The former has formed an altered pipe around the stockwork ore (Silica ore) and exhibits obvious alteration zoning: from the inner part outward, there exists gradual change from the quartz-adularia zone to the sericite-quartz zone, and from the lower part upward, the change is progressively from the chlorite zone to the quartz-sericite zone. The inert trace element method was employed to restore protolith composition of the ore-bearing rocks and make quantitative estimation of mass chemical change caused by alteration. Protoliths included dacite thyolite, thyolite and high-silica thyolite. With the evolution of magma towards strong acidity, lead and zinc increased, and copper was obviously depleted, implying that copper might have entered magmatic fluids. In the altered pipe, copper, lead and zinc are remarkably concentrated; distant from the altered pipe, copper is somewhat depleted, and lead and zinc are obviously depleted, indicating that lead and zinc in ore-forming substance were mainly derived from acid volcanic rocks which had suffered hydrothermal metasomatism and leaching. According to mass change of altered rocks, the authors outlined mass change of altered volcanic rocks in the Gacun ore district. The method that accurately traces the migration focus of hydrothermal fluids to outline orebodies is proposed on the basis of the calculation of mass change of the altered volcanic rocks. |
| |
| Keywords: | Gacun kuroko-type deposit hydrothermal alteration mass chemical change |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《矿床地质》浏览原始摘要信息 |
| 点击此处可从《矿床地质》下载免费的PDF全文 |
|
