中文摘要：

高空间分辨率紫外激光显微探针^40Ar-^39Ar定年技术在钾矿物环带、次生加大边、多世代矿物和难分选矿物之年代学研究中发挥越来越重要的作用。南大别山朱家冲榴辉岩经过角闪岩相退变质作用,形成榴闪岩。本文利用激光显微探针^40Ar-^39Ar定年技术成功测定了朱家冲榴闪岩之石榴子石环外的角闪石＂绿眼圈＂年龄为217±3Ma,石榴子石环内的多硅白云母年龄265±3Ma,环外的钠云母年龄223±4Ma。榴闪岩基质激光阶段加热^40Ar-^39Ar分析,获得高温阶段坪年龄为230Ma。多硅白云母年龄可能指示朱家冲榴辉岩超高压变质作用发生在265Ma之前;基质年龄代表了退变质作用峰期发生于230Ma;而217Ma角闪石＂绿眼圈＂为退变质作用晚期产物。这些^40Ar-^39Ar年龄印证了岩石薄片观察的矿物结晶顺序。

英文摘要：

The Zhujiachong eclogite, distributed in the county of Huangzhen （renamed as Tianhuazhen）, Taihu, Anhui Province, was originally taken as low-temperature and high-pressure （LT-HP） eclogite, or cold＂ eclogite. Coesite pseudomorphs, however, indicated that it experienced ultra-high pressure （UHP） metamorphism. Amphibolite- facies retrograde metamorphism turned eclogite into garnet-bearing amphibolite. This study analyzed the retrograde amphobolite facies mineralogy of the eclogite using ^40Ar-^39Ar ultraviolet laser ablation microprobe （UVLAMP） to determine the ages of discrete minerals. The ^40Ar-^39 Ar apparent ages indicate that the UHP phengite formed before 265 Ma. Amphibolite-facies retrograde metamorphism occurring from 242 Ma to 217 Ma, accompanied by the hydrothermal activity, is responsible for the formation of coarse-grained paragonite and fluid inclusions in vein amphibole until 200 Ma.