来自东南极西福尔丘陵附近冰碛物中沉积岩砾石的碎屑锆石LA-ICP-MSU-Pb年龄及其意义  

LA-ICP-MS U-Pb Ages and Its Significance of Detrital Zircon Come from Gravel of Sedimentary Rock in Moraine nearby Vestfold Hills, East Antarctica

作　　者：刘健[1] 赵越[1] 刘晓春[1] 崔建军[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081

出　　处：《地质学报》2011年第10期1585-1612,共28页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号40776004);国家海洋局极地考察办公室资助成果

摘　　要：东南极西福尔丘陵东南侧分布着长约20km带状冰碛物,这些冰碛物成分复杂,其中含有少量与该地区高级片麻岩的基岩显著不同的沉积岩砾石。根据冰川流动方向可以推测它们来自西福尔丘陵的东南侧的冰盖之下。对其中8个具有代表性的沉积岩砾石样品进行碎屑锆石LA-ICP-MSU-Pb年龄测试,其U-Pb表面年龄主要集中在2410～2600Ma和3340～3500Ma之间,缺乏1000Ma和500Ma变质年龄,这些信息不仅暗示在西福尔丘陵东南侧存在一个古太古代陆块,而且说明该碎屑岩的物源区的岩石组成相对较为单一。There are bands of moraine extending for 20 km which comprises of complex composition, including a few kinds of gravels of sedimentary rocks which were markedly different from the basement rocks of high-grade gneiss on the southeast side of the Vestfold Hills, East Antarctica. Based on the direction of glacier movement the source of the gravel is inferred to be under the glacier in the southeast of Vestfold Hills. LA-ICP-MS detrital zircon U-Pb age analyses of eight representative sedimentary gravel samples demonstrate that the U-Pb ages of the fdetrital zircons are predominantly in between 2410 Ma and 2600 Ma, and 3340 Ma and 3500 Ma, without the metamorphic ages of 1000 Ma and 500 Ma. This not only indicates that in the southeast of Vestfold Hills exists an Early-Archaean continental massif but also means that the source rocks of the clastic rocks are simple and relatively uniform in age.

关 键 词：东南极西福尔丘陵 冰碛物 沉积岩砾石 LA-ICP-MSU-Pb年龄 

分 类 号：P597.3[天文地球—地球化学]