东昆仑造山带纳赤台岩群基质地层发现中新世孢粉组合  

Discovery of Miocene Sporopollen from Matrix Strata of the Naij Tal Group-Complex in the Eastern Kunlun Orogenic Belt

作　　者：郭宪璞[1] 王乃文[1] 王大宁[1] 丁孝忠[1] 赵民[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037

出　　处：《地质论评》2007年第6期824-829,I0011-I0012,共8页Geological Review

基　　金：国家自然科学基金资助项目(编号40272019);中国地质调查局资助项目(编号200313000052)的成果

摘　　要：东昆仑造山带纳赤台岩群是一套混杂堆积地层,有外来岩块和基质地层之分别,以往根据岩块中的化石将该套地层划为下古生代的奥陶系—志留系。根据笔者等的研究和野外调查,2006年首次报道了在菜园子沟剖面该岩群基质地层中发现古近纪中—晚渐新世的孢粉44属31种。本文报道的是在水泥厂剖面该岩群基质地层中发现的新近纪中—晚中新世的孢粉化石44属33种。新近纪孢粉化石的发现对进一步厘定该岩群的地质时代、分析其古环境及东昆仑造山带的形成演化等方面具有重要的地质意义。Orogenic belts in China are characterized by large scale, various forms, widespreading and, mainly, intracontinental positions, which quite different from the European and American pericontinental orogens. There is certain scale tectonic--sedimentary mélange aggregation in each orogenic belt in China. For study of those knotty strata composed by mélange aggregation, it was a common approach using the fossils yielded in the exotic blocks to date whole strata including the matrix strata by same working principle and method as those used in stable areas or carbonate platforms. And then were inferred the relationship in age with strata joined evolution about m spatially with it and any orogenic belts is dating to ever disp formation of orogenic belt. So the age of formation and uted by different understandings, the key point causing not determined. This is a universal problem for division in age is the Naij Tal Group-complex in once assigned by the fossils found in the exotic blocks to the Late Ordovician or the Early Paleozoic. The Naij Tal Groups-complex is a suit of inhomogeneous metamorphosed strata located between the Nanshan Pass and the East--West Datan regions along the Qinghai--Xizang（Tibet） Highway near Golmud City of Qinghai Province. It is composed of metamorphosed sandstone, slate, phyllite, crystalline carbonate rock, intermediate--basic metamorphosed volcanic rock, intermediate--acidic metamorphosed volcanic rock, schist （partly） and migmatite, with total thickness about 8000m. This group-complex is of a great thickness and is chiefly made of grayish--green epizonal sandstone and slate of flysch facies, but only with less limestone and marble. By way of detailed survey and measure, four unusual contact relationships between limestone and marble and sandstone and slate have been found by authors. In this time, 44 genera and species Miocene sporopollen have been firstly found by authors in samples from the matrix strata in this group-complex and the Miocene Chenopodipollis--Persicarioipo

关 键 词：中新世 孢粉化石 纳赤台岩群 基质地层 东昆仑造山带 

分 类 号：Q914[天文地球—古生物学与地层学]