川西呷村超大黑矿型矿床成矿流体烯土元素组成

本文用ＩＣＰ－ＭＳ首次测定了呷村银多金属黑矿型矿床矿石流体包裹体中的稀土元素含量,研究表明,主成矿期流体稀土元素配分模式均为轻稀土富集,Ｅｕ具明显正异常,通过初步对比,本区主成矿期流体与东太平洋脊、大西洋脊等现代高温酸性地热系统热液具有相似的稀土模式,反映了它们物化条件的相似性;但前者∑ＰＥＥ高于后者,且两者Ｅｕ／Ｅｕ＾＊值不同,经过分析,本区成矿流体Ｅｕ正异常主要为Ｔ、ｐＨ、ｆｏ２控制,另外,围

Composition characteristics of rare earth elements in metallogenetic fluid of the Gacun superlarge "Kuroko"-type deposit.

REE in fluid inclusions of the Gacun VMS deposit are first measured by ICP MS. Chondrite normalized REE patterns in fluid inclusions of main mineralization stage show patterns with light REE enrichment and a huge positive Eu anomaly. Similar profiles have been found in some hydrothermal solutions from submarine system(East Pacific rise and Mid Atlantic ridge) and from crust, which indicate that the fluid share common geochemical characteristics. But REE content in Gacun ore forming fluids is higher than others, and their Eu anomaly is also different. It is extremely likely that the Eu is divalent in the main ore forming fluids of Gacun and in other solutions with high temperature, acidic, lower oxygen fugacity. Temperature, oxygen fugacity, pH value mainly constrain on the Eu huge anomaly and REE patterns in high temperature acidic solutions, while the pressure of water rock interaction zone and rock type may be the possible controlling factors.