论文部分内容阅读
格罗夫山主要出露高角闪-麻粒岩相深变质岩,包括长英质麻粒岩和花岗质片麻岩、镁铁质麻粒岩透镜体、紫苏花岗岩、后造山期的片麻状花岗岩、及造山期后细晶岩脉。岩石化学特征显示紫苏花岗岩、花岗质片麻岩和花岗岩属铝质A型深成岩系列,而长英质和镁铁质麻粒岩则来自岛弧、洋岛和洋中脊环境的表壳岩系列。测区以低角度面理构造为主,局部出现强剪切变形带。韧性变形可分为3个阶段:D1与前泛非期的构造事件有关,D2相应于区域性麻粒岩相变质作用,D3则可能反映泛非期造山作用后期的伸展作用.变质反应结构多显示为简单的区域性麻粒岩相变质作用,但镁铁质麻粒岩可鉴另出3个阶段:M1的温压条件为 800℃,9.3×105Pa;M2为800～8l0℃,6.4×105Pa;M3仅 650℃ 代表性花岗质片麻岩的锆石 U-Pb的离子探针分析显示峰期变质年龄集中于（529土14）Ma,花岗岩侵位年龄（534土 5）Ma,细晶岩脉年龄（501土 7）Ma,属于“泛非”期构造热事件.这些地质新证据显示在东南极内陆存在着一条从普里兹湾、格罗夫山到南查尔斯王子山的巨大“泛非”期造山带,应当是冈瓦纳最后拼合的缝合带.
The Grove Mountains are mainly characterized by high-angle flash-granulite facies-metamorphic rocks, including plagioclase granitic and granitic gneiss, mafic granulite lens, perilla granite, and post-orogenic Gneissic gneissic granite, and post-orogenic prograde veins. Petrochemical characteristics of peridotite, granitic gneiss and granite belong to the type A pluton series, while the felsic and mafic granulites come from the surface rocks of island arc, oceanic island and mid-ocean ridge series. The survey area is dominated by the low-angle texture and the strong shear deformation zone appears locally. The ductile deformation can be divided into three stages: D1 is related to the previous Pan-African tectonic events, D2 corresponds to regional granulite facies metamorphism, and D3 may reflect the extensional effect during the late Pan-African orogenic period. It shows simple regional granulite facies metamorphism, but mafic granulite can be seen in another three stages: the temperature and pressure conditions of M1 are 800 ℃, 9.3 × 105Pa; M2 is 800 ~ 8l0 ℃, 6.4 × 105Pa. The ion probe analysis of U-Pb zircons from the representative granitic gneisses of M3 only shows that the peak metamorphic ages are (529 ± 14) Ma, granite emplacement age (534 ± 5) Ma, Prunella ages (501 ± 7) Ma, belong to the “Pan-African” tectono-thermal event.These new geologic evidence show that there is an inland inland of the Prydz Bay from Prydz Bay, Grove Mountains to South Prince Charles The huge “Pan-African” orogen should be Gondwana’s final splice.