青海牛苦头铁多金属矿床岩石地球化学特征及找矿意义

Geochemical Characteristics and Prospecting Significance of Polymetallic Rock Deposit in Niukutou of Qinghai

系统调查了岩浆岩的地球化学特征,认为牛苦头铁多金属矿床属花岗岩属钙碱性-高钾钙碱性系列,具有I型花岗岩特征,而微量元素地球化学特征,自闪长岩-花岗闪长岩-二长花岗岩分异程度逐渐增高,各岩性轻稀土分馏明显,重稀土分馏较弱,反映出岩浆结晶分异过程中可能存在轻稀土元素含量较高的矿物结晶分离。区内花岗岩总体形成于后碰撞构造环境,矿床的形成与构造岩浆演化关系密切。

Geochemical characteristics of magmatic rock was systematically investigated,the polymetallic deposit of Niukutou was identified as calc-alkali granite-high potassium,calcium,alkaline series,it has I type granite characteristics,its differential degree increased gradually from diorite-granodiorite-monzogranite,the light rare earth fractionation of each lithology is obvious,heavy rare earth fractionation is weak,it reflects mineral crystal separation with high content of light rare earth might be existed in magma crystallization differentiation process.Granite in the area totally formed in post-collision construction environment,the formation of deposit has close relationship with tectonomagmatic evolution.