Ziucon U-Pb age framework of Huashan-Guposhan intrusive belt,western part of Naniing Range,and its geological significance.

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.