论辽宁省侵入岩成因

    THE ORIGIN OF INTRUSIVE ROCKS IN LIAONING PROVINCE

    • 摘要: 文章把辽宁侵入岩划分为三大成因类型。从地质特征、稀土元素分布型式、元素对特征、锶硫同位素组成、地球化学特征等对三种成因类型岩体进行分析对比。认为同熔型侵入岩成矿作用好,重熔型侵入岩成成矿作用次之,幔源型侵入岩成矿作用较差。

       

      Abstract: The intrusive rocks may be classified into the mantle-derlved,mantle-crust syntectic and crustal anatectic types,according to the geological characteristics, mineralization,REE,Sr and S isotopes,petrochemistry,trace elements, mineral geochemistry and accessory minerals of the intrusive rocks. Mantle-derived type The rocks of this type consist of basic-ultrabasic rocks and plagiogranite.Cr and Ni mineralizations are represented.The REE pattern of the plagiogranite is flat and ∑REE is low(<10 ppm).87sr/86sr≤0.704.The contents of alkali metals and related elements(Sr,Ba,Zr and F)are low. Mantle-crust syntectic type The rocks are represented by diorite,granodio- rite,porphyritic admellite and granite porphyry.The intrusion was accompanied by volcanic eruption.Mo,Cu,Pb,Zn and Au mineralizations are more common. There oceur porphyry deposits.REE is intermediate in content(150 ppm±on average);87Sr/86Sr>0.704.-0.708;crystal chemistry shows the biotite to be magmisio-biotite and magnesioferri-biotite;AlVI<0.3 and Mg>1;accessory minerals(Cr and Ni)and high and the contents of alkali metals and related elements are intermediate. Crustal anatectic type The rocks of this type are dominated by porphyroid admellite,no volcanic rocks being present.The type is characterized by W mineralization,high ∑REE (>200 ppm on average),87Sr/86Sr>0.710,AlVI>0.3 and Mg<1.1.Crystal chemistry shows the biotite to be ferrebiotite.The contents of refractory elements are low and the contents of alkali metals and related elements are high.

       

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