海南岛琼中地区琼中岩体锆石U-Pb年龄及其地质意义  

ZIRCON U-PB AGE AND ITS GEOLOGICAL SIGNIFICANCE FOR QIONGZHONG PLUTON IN QIONGZHONG AREA, HAINAN ISLAND

作　　者：李孙雄[1] 云平[1] 范渊[1] 周进波[1] 

机构地区：[1]海南省地质调查院,海南海口570206

出　　处：《大地构造与成矿学》2005年第2期227-233,241,共8页Geotectonica et Metallogenia

摘　　要：琼中地区琼中岩体为钙碱性的铝弱过饱和型花岗岩,具有壳源物质来源,岩石普遍发育定向组构,生成于同碰撞期-晚造山期.其锆石U-Pb年龄为226.5±2.9～234.2±2.3Ma,为晚三叠世.通过区域分析,认为海南岛海西-印支期花岗岩从西往东,具有由老至新的演化规律,形成了略向南面突出的弧状面理构造.表明同期造山活动消减方向由西至东,呈现出剪刀式闭合的特征.Qiongzhong pluton was formed by slender supersaturation calc-alkalic granites, with involvement of crustal materials in the rock constituents. Orientated fabrics are very common, which suggests that it was formed during apposition-collision in the late orogenic period. The Zircon U-Pb dating gives results of 226.5±2.9 - 234.2±2.3 Ma, indicating that it belongs to Late Triassic. Regional geological study suggests that from east to west the Hercynian-Indosinian granites in Hainan Island show an evolution trend of increasingly younger ages and demonstrate an arc-shaped foliation structure. These suggest that the termination direction of the orogenic movement is characterized by shear convergence extending from west to east.

关 键 词：岩体时代 地质意义 海南岛 

分 类 号：P597[天文地球—地球化学]