Based on the theory and method of the petrogeochemistry, the major element, REE and trace element of the Middle and Upper Devonian in the Dachang orefield were analyzed, the relationship between the Devonian and minerals was discussed, the favorable metallogenic conditions and its critical control to the ore deposit were also elaborated. The results suggest that the major elements of the Devonian consist of SiO2, CaO, Al2O3, Fe2O3, MgO, Na2O and K2O, yet SiO 2 and CaO are dominant. The calcium oxide content of Nabiao formation is the maximum, but the SiO 2 content of the other formations seems to be too high in different degrees, which closely relates to the lithological characteristics and rock assemblage of Devonian in Dachang orefield. According to the hydrothermal mode of Al 2 O 3-SiO 2 , the depositional environment of Devonian was variable with multiple sources, which led to the diverse lithology and complex rock formations. The content ofΣREE of Devonian is 2.9×10−6−318.77×10−6 , among which the Nabiao formation depletes LREE and HREE elements, yet the Luofu formation relatively enriches LREE and HREE elements. The trace elements of Devonian are composed of Ba, Rb, Sr, Th, U, La, Ce, Pr and Nd. The special rock type and lithological combination of Devonian are the favorable factors for the metal enrichment.%利用岩石地球化学的理论与方法，对大厂矿田的主要赋矿地层泥盆系中、上统开展了主量元素地球化学、稀土元素地球化学以及微量元素地球化学的分析与研究，对泥盆系地层与大厂矿田矿床与矿产的关系进行了探讨，阐述了泥盆系的有利成矿条件及其对矿床的关键控制作用。结果表明，泥盆系地层主量元素成分为SiO 2、CaO、Al 2 O 3、Fe 2 O 3、MgO、Na 2 O以及K 2 O等，以SiO 2和CaO为主体，其中，纳标组地层CaO含量最高，其余各组地层SiO 2含量均表现为不同程度的偏高，这与大厂矿区泥盆系地层的岩性特征以及岩石组合密切相关。利用Al 2 O 3-SiO 2岩石热水成因模式显示，泥盆系形成过程中沉积环境多变，岩石物源具有多来源的特点，也从一定程度上导致了泥盆系地层多样化的岩性特点以及复杂的岩石建造。泥盆系ΣREE含量变化于(2.9~318.77)×10−6之间，其中，纳标组地层表现出轻、重稀土元素亏损，罗富组地层则表现为轻、重稀土元素富集。泥盆系地层的微量元素组成主要包括Ba、Rb、Sr、Th、U、La、Ce、Pr、Nd等。泥盆系不同组地层独特的岩石类型与岩性组合，是金属成矿元素发生富集的有利因素。
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