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| 1 | 大别山碧溪岭深色榴辉岩和片麻状花岗质岩石SHRIMP分析——晋宁期高压—超高压变质作用的同位素年代学依据显示文摘本文报道大别山安徽省岳西县碧溪岭深色榴辉岩和片麻状花岗质岩石的锆石SHRIMP分析结果。深色榴辉岩的原岩为基性凝灰岩,锆石在岩石中主要产于石英、石榴子石和绿辉石内,为高压一超高压变质作用的产物,内部主体形成年龄约为757±7Ma,代表高压—超高压榴辉岩相变质事件的时代;经受了后期流体改造的锆石边部年龄为223±3Ma。在片麻状花岗质岩石中,发育韵律环带结构的深熔锆石形成于约727±15Ma,受后期流体改造的锆石边部年龄为219±3Ma。综合野外地质关系、区域地质背景和锆石的岩相学特征,笔者提出了碧溪岭榴辉岩相岩石高压—超高压变质作用发生于晋宁期,印支期仅代表一次后期流体改造事件的观点。 | 程裕淇 刘敦一 I.S.Williams 简平 庄育勋 高天山 | 2000 | 地质学报2000，74，3： | 89 |
| 2 | 大别山西部河南罗山熊店加里东期榴辉岩锆石特征及SHRIMP分析结果显示文摘熊店榴辉岩产于大别山西部苏家河构造混杂岩带内,是典型的高压—超高压中温榴辉岩。作者应用岩相学结合阴极发光和扫描电镜方法,较系统地研究了榴辉岩中锆石在岩石中的赋存状态、内部结构及表面特征。锆石主要产于石榴子石等变质矿物内,与主晶界面清晰,具有多晶面等变质锆石特有形貌特征,内部均匀或发育变质生长结构,从而说明它们是变质作用的产物。SHRIMP分析表明,锆石^(206)Pb/^(238)U年龄为335~424Ma,有放射性成因铅丢失现象,因此可以推断424±5Ma代表高压变质事件的最小年龄。结合已有的Sm-Nd全岩和内部等时线、冻蓝闪石^(40)Ar-^(39)Ar及单颗粒锆石U-Pb和^(207)Pb/^(206)Pb年龄资料综合分析,熊店榴辉岩的峰变质年龄应限于424~480Ma之间。这一研究进一步说明大别山存在加里东期榴辉岩。 | 简平 刘敦一 杨巍然 I.S.Williams | 2000 | 地质学报2000，74，3： | 36 |
| 3 | SHRIMP dating of zircons from the Caledonian Xiong-dian eclogite,western Dabie Mountains,China显示文摘This note reports the SHRIMP U-Pb data of zircons from the Caledonian Xiongdian eclogite, western Dabie Mountains. Zircons from the rock occur mainly in garnet and other metamorphic minerals with sharp boundaries and exhibit textures growing under metamorphic conditions. Analyses of 7 grains give 206Pb/238U ages ranging from 335 to 424 Ma, showing a certain degree of radiogenic lead loss. This suggests a minimum age of (424±)Ma for the metamorphic zircons, as well as the high-pressure metamorphic event. The outer peripheral zone of a zircon gives 206Pb/238U age of about 300 Ma. Combined with Sm-Nd, 40Ar-39Ar, U-Pb and 207Pb/206Pb ages, the peak metamorphism of the Xiongdian eclogite is documented between 424-480 Ma. | JIAN Ping LIU Dunyi YANG Weiran I.S.Williams | 2001 | Chinese Science Bulletin2001，46，1： | 6 |
| 4 | Petrographic and SHRIMP Studies of Zircons fromthe Caledonian Xiongdian Eclogite, NorthwesternDabie Mountains显示文摘The Xiongdian eclogite occurring in the Sujiahe tectonic melange zone at Luoshan County, Henan Province, in the western Dabie Mountains, is typical high-pressure (HP)-ultrahigh-pressure (UHP) and medium-temperature eclogite. The occurrence, internal texture and surface characteristics of zircons in eclogite were studied rather systematically petrographically combined with the cathodoluminescence (CL) and scanning electron microscope (SEM) methods. Zircons are mainly hosted in garnet and other metamorphic minerals with sharp boundaries, have a multifaceted morphology and are homogeneous or exhibit a metamorphic growth texture in the interior, thus indicating that they are the product of metamorphism. SHRIMP analyses give zircon 206Pb/238U ages of 335 to 424 Ma and show a certain degree of radiogenic Pb loss; therefore it may be inferred that the age of 424? Ma represents the minimum age of a HP-UHP metamorphic age. From the above analyses coupled with previous Sm-Nd, 40Ar-39Ar, U-Pb and 207Pb/206Pb age | I.S.WILLIAMS | 2000 | Acta Geologica Sinica(English Edition)2000，74，4： | 4 |
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