CAJ | 학술논문

古龙花岗岩株群包括大村、古龙、思泰、社山、上木水、大坡等侵入体，岩性主要为石英闪长岩一英云闪长岩一花岗闪长岩一二长花岗岩组合，岩石普遍含角闪石。岩石化学系列属于钙碱性系列一高钾钙碱性系列，主量元素具高CaO低K2O的特征。稀土总量低，轻稀土富集，弱Eu亏损。微量元素Nb、Ta、Sr、P、Ti强烈亏损，Th、u、Zr、Hf相对富集。对古龙岩体进行了高精度的LA—ICP—MS锆石u-Pb定年，获得石英闪长岩等时线年龄为445．9-I-1．2Ma（MSWD=0．035）。研究认为古龙花岗岩株群形成于早志留世，属于加里东期I型花岗岩，形成于华南加里东期造山带俯冲一碰撞挤压构造背景，岩浆物质来源主要为俯冲带幔源岩浆并混入了部分壳源物质。
고룡화강암주군포괄대촌、고룡、사태、사산、상목수、대파등침입체，암성주요위석영섬장암일영운섬장암일화강섬장암일이장화강암조합，암석보편함각섬석。암석화학계렬속우개감성계렬일고갑개감성계렬，주량원소구고CaO저K2O적특정。희토총량저，경희토부집，약Eu우손。미량원소Nb、Ta、Sr、P、Ti강렬우손，Th、u、Zr、Hf상대부집。대고룡암체진행료고정도적LA—ICP—MS고석u-Pb정년，획득석영섬장암등시선년령위445．9-I-1．2Ma（MSWD=0．035）。연구인위고룡화강암주군형성우조지류세，속우가리동기I형화강암，형성우화남가리동기조산대부충일팽당제압구조배경，암장물질래원주요위부충대만원암장병혼입료부분각원물질。
Gulong granite stock group is composed of the intrusive bodies in Dacun, Gulong, Sitai~ Shangmushui, Dapo, etc., and is mainly assembly of quartz diorite- tonalite- granodiorite- admellite, and commonly contain hornblende. Those rocks are belong to calc-alkaline series and high-K talc alkaline series, with higer CaO content. The rocks are characterized by low REE contents, consistently show LREE-riched patterns, weakly Eu depletion, depletion of Nb, Ta, Sr, P, Ti, and relatively rich in Th, U, Zr, Hi'. Zircon LA-ICP-MS U-Pb dating of quartz diorite yielded the isochron age of 445.9 _+ 1.2 Ma(MSWD=0.035 ) in Gulong granites, and indicated that Gulong granites stock group were formed in Early Silurian, and is part of Caledonian I-type granites which were formed in Caledonian orogenic belt of South China subduction-collision squeezing tectonic setting. The source for Gulong granite mainly are the mantle-derived magma from subduction zones, partly mixed with the crustal material when magma intrusion.