CAJ | 학술논문

　　本文对牛栏岭细粒铁锂云母花岗岩和似斑状铁锂云母花岗岩进行了锆石U-Pb年代学和岩石地球化学研究，讨论了岩体的形成时代、成因类型、源区性质及其与成矿关系。两种岩性锆石的LA-ICP-MS U-Pb定年表明，其加权平均年龄分别为（223.6±1.7）Ma和（223.7±1.7）Ma，属印支晚期构造岩浆活动的产物。岩石相对富集SiO2，K2O，Na2O，P2O5和贫CaO，MgO，TiO2；A/CNK值为1.08~1.31，落入强过铝质花岗岩区域；CIPW计算结果给出的岩体标准矿物刚玉的含量为1.6%~4.5%；岩体的球粒陨石标准化稀土配分曲线呈轻微右倾形，具有强烈的Eu负异常，δEu为0.01~0.05。岩体富集Cs， Rb，K等大离子亲石元素（LILE）和U，Pb，Hf，Ta等高场强元素（HFSE），明显亏损Ba，Sr，Ti等元素；锆石饱和温度介于631℃~681℃之间，低于S型花岗岩的平均锆石饱和温度。岩体中发现有（248±4）Ma和（1947±23）Ma的继承锆石，暗示其源区可能为晚古元古代的壳源物质，印支早期岩浆物质也可能参与了岩体的形成。岩体的地质地球化学特征研究表明，岩体可能为牛栏岭地区的W-Sn成矿作用提供W-Sn来源，暗示牛栏岭地区可能存在有224 Ma左右的成矿作用，印支期成矿作用可能成为栗木矿区乃至南岭西段今后找矿工作的一个重点方向。
　　본문대우란령세립철리운모화강암화사반상철리운모화강암진행료고석U-Pb년대학화암석지구화학연구，토론료암체적형성시대、성인류형、원구성질급기여성광관계。량충암성고석적LA-ICP-MS U-Pb정년표명，기가권평균년령분별위（223.6±1.7）Ma화（223.7±1.7）Ma，속인지만기구조암장활동적산물。암석상대부집SiO2，K2O，Na2O，P2O5화빈CaO，MgO，TiO2；A/CNK치위1.08~1.31，락입강과려질화강암구역；CIPW계산결과급출적암체표준광물강옥적함량위1.6%~4.5%；암체적구립운석표준화희토배분곡선정경미우경형，구유강렬적Eu부이상，δEu위0.01~0.05。암체부집Cs， Rb，K등대리자친석원소（LILE）화U，Pb，Hf，Ta등고장강원소（HFSE），명현우손Ba，Sr，Ti등원소；고석포화온도개우631℃~681℃지간，저우S형화강암적평균고석포화온도。암체중발현유（248±4）Ma화（1947±23）Ma적계승고석，암시기원구가능위만고원고대적각원물질，인지조기암장물질야가능삼여료암체적형성。암체적지질지구화학특정연구표명，암체가능위우란령지구적W-Sn성광작용제공W-Sn래원，암시우란령지구가능존재유224 Ma좌우적성광작용，인지기성광작용가능성위률목광구내지남령서단금후조광공작적일개중점방향。
The samples from the Niulanling fine-grained and porphyritic granites have been analyzed for zircon U-Pb ages and whole rock geochemical compositions to discuss the emplacement age, genetic type, source and relationship with the mineralization. LA-ICP-MS zircon U-Pb dating results of the two granite samples indicate that the granites formed in the Late Indosinian period with weighted average age of (223.6±1.7) Ma and (223.7±1.7) Ma, respectively. The granites are rich in SiO2,K2O, Na2O and P2O5 and poor in CaO, MgO and TiO2. The granites are strongly peraluminous with the A/CNK values changing from 1.08 to 1.31. CIPW-normative calculation gives 1.6%-4.5% corundum. Chondrite-normalized REE diagrams of the granites have slightly right-leaning shape with strong negative Eu anomalies and δEu values vary from 0.01 to 0.05; The granites are enriched in LILE (Cs, Rb, K) and HFSE(U, Pb, Hf,Ta), but are relatively low in Ba, Sr and Ti. The zircon saturation temperatures (t zr) are from 631 to 681 ℃, which are lower than the averageing value of S-type granites. The (1947±23) Ma inherited zircon indicates that the source region of the granite is mainly Late Palaeoproterozoic crustal materials. The inherited zircon of (248±4) Ma suggests an addition of the Early Indosinian magma in the formation of the granites. The geological and geochemical characteristics of the granites show that the granites could provide W and Sn for the W-Sn mineralization in the Niulanling district and there might be mineralization of about 224 Ma in this area. The Indosinian mineralization should be the key target in the Limu district and very important even for western Nanling Range as a whole in the further ore-prospecting work.