Ziucon U-Pb age framework of Huashan-Guposhan intrusive belt,western part of Naniing Range,and its geological significance.
Ziucon U-Pb age framework of Huashan-Guposhan intrusive belt,western part of Naniing Range,and its geological significance.
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作者：
Zhu Jin
花山-姑婆山侵入岩带位于南岭西段，由牛庙、同安、花山、金子岭、五阳山、姑坡山等花岗岩类岩体组成。采用SHRIMP法、LA-ICPMS法和熔融法对10个样品进行了U-Pb年龄测定，结果表明，该带主相花岗岩和闪长岩体侵位的时间间隔为160~163 Ma，这些花岗岩类在时间、空间、物质来源、大地构造背景和成因机制等方面都有密切的联系。利松花岗岩和利松镁铁质包体的同步年龄排除了围岩包体或重熔变质岩重熔岩中包体的可能性，为岩浆混合提供了重要证据。后期新路细粒花岗岩具有良好的分馏特征，其锆石U-Pb年龄为151 Ma，比主期花岗岩晚10 Ma左右。它可能代表了本区花岗岩岩浆房的分离结晶和演化的持续时间。桂岭和大宁花岗岩类侵位于加里东晚期。
Huashan-Guposhan intrusive belt is located in the western part of the Nanling Range.It is composed of Niumiao,Tong' an,Huashan,Jinziling,Wuyangshan,Guposhan,etc.granitoid bodies.The U-Pb age dating of 10 samples by SHRIMP,LA-ICP-MS and melting methods reveals that the major phase granitic and dioritic bodies in this belt were emplaced in a narrow time interval of 160 ～163Ma.These granitoids are closely related in time,space,material sources,geotectonic setting and genetic mechanism. The synchronous age of Lisong granite and Lisong mafic enclave excludes the possibility of xenolith from country rocks or restite of remelted metamorphic rocks,and provides an important evidence for magma mingling.The later stage Xinlu fine-grained granite with well evolved fractionation characteristics has a zircon U-Pb age of 151 Ma,which is about 10Ma later than the major phase granitoids. It probably represents the time duration of fractional crystallization and evolution of the granitic magmatic chamber in this region. The Guiling and Daning granitoid bodies were emplaced in the late Caledonian period.