【摘 要】
:
Altay granulite (AG), which represents the product of high-grade metamorphism in the lower crust, was newly found in thc Wuqiagou area, Fuyun County in the Alta
【机 构】
:
Department of Earth Sciences,Institute of Geology and Geophysics
【基金项目】
:
This study was supported by the National Key Project for Basic Research on the Central Asia Orogenic and Metallogenic Belt;the Exemplary Young Teacher Education and Scientific Research Award Plan of C
论文部分内容阅读
Altay granulite (AG), which represents the product of high-grade metamorphism in the lower crust, was newly found in thc Wuqiagou area, Fuyun County in the Altay orogenic belt, Northwest China. It is composed mainly of hypersthene, augite, basic plagioclase, amphibole and brown biotite. Its mineral compositions of amphibole and biotite are rich in Mg/(Mg+Fe2+) and Ti. Geochemically, the AG is enriched in Mg/(Mg+Fe2+) and A12O3, and poor in CaO, with depletion of U, Th, K and Rb contents. Furthermore, geochemical data reflect that the protolith of the AG is igneousgenetic calc-alkalinc basalt formed under an island arc environment. The AG has ∑REE of 92.38-96.58 ppm and enriched LREE model with weak positive Eu anomaly of 1.09-1.15. In the MORB normalized spider diagram, the AG shows tridoming pattern with a strong negative Nb anomaly and medium negative P and Ti anomalies, reflecting that the AG has tectonic relation with subduction or subduction-related materials. The P-Tconditions of peak metamorphism of the AG arc 750-780°C and >0.6-0.7 GPa. Retrograde metamorphism implies that the protolith of the Altay granulite might undergo a metamorphic process along a clockwise P-T trajectory. Thereforc, thc formation and evolution of thc AG may have a genetic association with continental collision/orogeny and the AG was taken into the Late Paleozoic meta-strata by way of tectonic emplacement.
其他文献
In order to estimate water resources renewability scientifically, an Ideal Interval Method of Multiple Objective Decision-Making (IIMMODM) is presented. This me
In recent years, mountain regions are attracting great attention to Indian tourists in general and foreign tourists in particular. The potential mountain resour
全面加强对桥梁的养护与管理,已刻不容缓.本文针对高速公路桥粱养护管理进行了探讨.
Minimum Mean Square Error (MMSE) multiuser detection yields the highest output SINR among all linear detectors. The blind MMSE linear detector can be implemente
中平能化应急无线调度系统利用移动通信现有网络建立覆盖集团公司各煤炭生产矿、发电厂、降压站、洗煤厂、安检、救护、化工、焦化及异地起企业和区域公司等单位,满足调度通
The water exchange between the subpolar and subtropical gyres of the North Pacific is demonstrated by the simulation of chlorofluorocarbon (CFC) using an ocean
The closure of third stage diversion channel for the Three Gorges Dam is characterized by large closure discharge, large drop in water surface, and high gap vel
The Late Permian Emeishan Large Igneous Province (ELIP) is commonly regarded as being located in the western part of the Yangtze craton, SW China, with an asymm
The Neoproterozoic Doushantuo Formation at Weng'an in Guizhou Province of South China consists of phosphorites and dolomites.Three types of samples are recongni
The critical heat flux (CHF) in the forced convective boiling with a wall jet has been investigated.The experiments of CHF with a wall jet have been performed o