山东龙宝山岩体稀土元素特征及矿源研究

龙宝山岩体是燕山期多阶段岩浆活动形成的中偏碱性杂岩体,其稀土元素特征为:wΣREE为地壳丰度的2.5倍,wLREE/wHREE为地壳的近9倍,轻稀土强烈富集,δEu、δCe均呈弱负异常,各期侵入岩及含金石英脉的稀土元素分布型式基本相似,呈向右陡倾斜线,但石英脉中稀土总量更高、轻稀土更为富集。研究结果表明:岩浆和成矿物质最初可能均来源于上地幔的同一岩浆房,并在岩浆上侵过程中不同程度地同化混染了地壳物质。

REE CHARACTERISTICS AND ORE SOURCE STUDIES OF LONGBAOSHAN COMPLEX

In Mesozoic, Longbaoshan intermediate-alkaline complex was formed as a result of two stages of magmatic intrusion. As shown by statistical analysis of REEin the complex, the total content of w ΣREEis nearly 2.5 times as high as the Clarke value, the ratio of w LREE/w HREEis nearly 9 times that of the crust, and light REEis greatly enriched, whereas Eu and Ce are slightly depleted. The REEdistribution patterns of various stages of intrusives and auriferous quartz veins are basically similar to each other, all dipping steeply towards the right. Nevertheless, ΣREEand LREEare richer in auriferous quartz veins than in magmatite. Combined with the geological and geochemical characteristics, the authors conclude that magma and metallogenetic materials of the complex were derived mainly from the same magma chamber in the upper mantle, and assimilated and mixed with the wall rocks during the intrusion of magma into the crust.