【摘 要】
：
The Jinghong mafic–ultramafic complex, exposed in the eastern margin of the Lancangjiang tectonic belt, is related to the subduction of the Paleo-Tethys Ocean. Its petrogenesis plays a key role in constraining the tectonic evolution of the eastern Paleo-T
【机 构】
：
Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources,Institute of Geology,Chinese
论文部分内容阅读
The Jinghong mafic–ultramafic complex, exposed in the eastern margin of the Lancangjiang tectonic belt, is related to the subduction of the Paleo-Tethys Ocean. Its petrogenesis plays a key role in constraining the tectonic evolution of the eastern Paleo-Tethys Ocean in southwestern China. In this study, we present petrological, geochemical and geochronological results of the Jinghong complex rocks, in order to decipher their origin and tectonic significance. The Jinghong mafic–ultramafic complex was composed of peridotite, gabbro, basalt and minor plagiogranite. Whole-rock geochemical data of the mafic rocks indicate that they have both MORB and IAB affinities and plot in the back-arc basin basalt (BABB) field in the FeO*/MgO vs. TiO2 diagram. Combined with their trace element characteristics, it can be concluded that the Jinghong mafic–ultramafic complex represents an ophiolite suite that was formed in a back-arc ocean basin. Precise LA-ICP-MS zircon U-Pb dating yielded weighted mean 206Pb/238U ages of 298.4 ± 1.7 Ma, 294.3 ± 1.6 Ma, and 292.8 ± 2.0 Ma for gabbroic rocks from this complex, which indicates that the Jinghong ophiolites were formed during the early Permian (298–293 Ma). We propose that during subduction of the main Paleo-Tethys Ocean, a back-arc ocean basin was formed at the east of the Lancangjiang tectonic belt.
其他文献
【摘要】能源是发展国民经济的基础, 近年来，随着人们对于自然能源无限度的开采与利用，现在已经造成了自然能源的严重匮乏，在建筑施工中实施节能技术是十分必要的，其具有的意义也是较为深远的。而建筑节能也越来越被国家重视,最近几年,国家相继颁发了一系列建筑节能标准来规范建筑节能市场。影响建筑能耗的因素很多,除了建筑设计要符合国家的节能标准外,施工中严格按照要求控制节能工程质量也是非常重要的。 【关键词
Viruses can be transmitted from animals to humans (and vice versa) and across animal species.As such,host-virus interactions and transmission have attracted considerable attention.Non-human primates (NHPs),our closest evolutionary relatives,are susceptibl
New integrated geochemical studies are reported for Jurassic granites of the Xingcheng area in the northeastern North China Craton. U–Pb zircon data indicate that the Huashan and Taili monzogranites were emplaced during the Early (189 ± 2 Ma) and Late (15
Flatheads are valuable commercial fish species endemic to the Indo-West Pacific.Due to their economic value and unique biological traits,such as metamorphosis and camouflage,they serve as ideal marine organisms for studies on demersal adaptation and evolu
摘要：随着我国建筑行业的深入发展，对建筑施工项目管理就显得越来越重要。但是，目前我国建筑施工项目管理还有待完善，要随时适应社会的变化和建筑市场的变化。本文就建筑施工项目管理存在的主要问题，分析完善建筑施工项目管理的措施，提出自己的一些看法。 关键字：建筑 施工项目管理 创新管理 中图分类号：TU7文献标识码： A 一、目前建筑施工项目管理存在的主要问题 1.建筑施工项目成本管理粗放
The large yellow croaker (Larimichthys crocea),which is an economically important mariculture fish in China,is often exposed to environmental hypoxia.Reactive oxygen species (ROS) homeostasis is essential for the maintenance of normal physiological condit
The western segment of the Main Tianshan shear zone (MTSZ) branches into three major dextral strike-slip shear zones in the Borohoro Ranges, northwestern China. Mylonitic rocks within these zones exhibit vertical foliations, subhorizontal lineations, and
The genetic adaptations of various organisms to heterogeneous environments in the northwestern Pacific remain poorly understood.Heterogeneous genomic divergence among populations may reflect environmental selection.Advancing our understanding of the mecha
ObjectivernThe Zhongdian area, Yunnan Province, is located in the southern of the Yidun Island arc belt in the Tethys-Himalayan metallogenic area, and is one of the important copper polymetallic mineral resource bases in China.Based on the previous studie
The garnet muscovite granitic pegmatite of Um Solimate, in southern Egypt, represents a promising asset for strategic and economic metals, especially Bi–Ni–Ag–Nb–Ta as well as U and Th. The ore bodies occur as large masses, pockets and/or veins of very co