CAJ | 학술논문

桂东北海洋山岩体为岩性单一的二长花岗岩岩基。锆石SHRIMP U-Pb定年显示海洋山岩体主结晶年龄为431±7 Ma（MSWD=3.14）,与赣湘桂内陆加里东期花岗闪长岩-二长花岗岩形成时代相似,为同一期成岩事件的产物。元素地球化学研究表明,绝大多数样品具有富硅（～68%）,富钾（K2O/Na2O〉1.5）,弱过铝质（A/CNK均值1.05）和低Al2O3/TiO2值（〈100）、高CaO/Na2O值（〉0.3）的特征。与临区浅变质基底一致的εNd（t）值（-8.0～-8.6）和T2DM值（1.82～1.87 Ga）,指示其理想源区为成熟度较低的古老变质杂砂岩。进一步的宏观地质特征和华南加里东造山带构造演化序列分析表明,海洋山岩体属于陆壳改造型花岗岩,其形成的构造环境很可能为汇聚造山向非造山转化的后造山伸张环境。
계동북해양산암체위암성단일적이장화강암암기。고석SHRIMP U-Pb정년현시해양산암체주결정년령위431±7 Ma（MSWD=3.14）,여공상계내륙가리동기화강섬장암-이장화강암형성시대상사,위동일기성암사건적산물。원소지구화학연구표명,절대다수양품구유부규（～68%）,부갑（K2O/Na2O〉1.5）,약과려질（A/CNK균치1.05）화저Al2O3/TiO2치（〈100）、고CaO/Na2O치（〉0.3）적특정。여림구천변질기저일치적εNd（t）치（-8.0～-8.6）화T2DM치（1.82～1.87 Ga）,지시기이상원구위성숙도교저적고로변질잡사암。진일보적굉관지질특정화화남가리동조산대구조연화서렬분석표명,해양산암체속우륙각개조형화강암,기형성적구조배경흔가능위회취조산향비조산전화적후조산신장배경。
Haiyangshan granite is a monzogranitic batholith in northeast Guangxi province.Zircon SHRIMP U-Pb dating of this granite yields an age of 431±7 Ma（MSWD=3.14）,same as granodioritic-monzogranitic plutons of inland area like Jiangxi,Hunan and Guangxi,providing temporal constraint of a diagenesis event in late Caledonian.Major,trace elements and Nd isotopic compositions of several rock samples are reported to constraints its magma source and geodynamic setting in northeast Guangxi province.The geochemical of those samples,which behavior as relatively low SiO2 contents（0.3） ratios,with low εNd（t）（-8.0～-8.6）and relatively high T2DM values（1.82～1.87 Ga）,indicating they are originated from the salic crust with metamorphosed graywacks as its major composition.Integrated with its geological feature and evolution of Caledonian orogen of Southeast China,we advocate that Haiyangshan batholith belongs to continental crust-transformation series and it forms in late orogeny setting between orogenic convergence and anorogenic periods.