地质学报2016，Vol.90Issue(2)：284-303,20.
湖南塔山、阳明山花岗岩的岩石成因：来自锆石 U-Pb 年龄、地球化学及 Sr-Nd 同位素证据
Petrogenesis of the Tashan-Yangmingshan Granitic Batholiths:Constraint from Zircon U-Pb Age,Geochemistry and Sr-Nd Isotopes
摘要
Abstract
The Yangmingshan-Tashan batholith,located at the junction of the Yangtze and Cathysia blocks,is mainly composed of monzonitic granites with different granularity and phenocryst content.In this article, a research combined of LA-MC-ICP-MS zircon U-Pb chronology,geochemistry and Sr-Nd isotopes on several samples of different lithologies of granitoid is reported to constraint its petrogenesis and tectonic setting.The result shows three granitic samples of different granularity from the Tashan bathoilth yield ages from 213.4 ~ 221.5 Ma,while one sample from Yangmingshan batholith yields a age of 213.7 ± 1.0Ma,both of them belong to late Indosinian.Geochemically these samples are relatively enriched in SiO2 (70.43% ~ 74.06%)and Al2 O3 (A/CNK = 1.03 ~ 1.24 )that can be easily identified as peraluminous series.Further discrimination indicates metagraywackes are the dominate source materials to the Tashan batholith,and metapelites to the Yangmingshan batholith.High Rb、Th、U、Ta abundances and strong depletion of Ba,Sr,Nb,Ti,Eu,elements indicates they experience high fractionation process.High (86 Sr/87 Sr)i ratios (0.72993~0.77391)and lowεNd (t)values (-9.9~-12.11)with t DM2 (Nd)of 1801 ~1978Ma reveal that their sources have involved in the crustal cycle for a long time.Intergrated with Indosinian tectonic involvement of South China,partial melting of thickened middle crust under local extension-thinning mechanism may be the key factor controlling the granitic intrusionism of the Tashan-Yangmingshan region.3523 Ma inherited core of one zircon show that ancient Archaeozoic basement did exist in this region.关键词
锆石 U-Pb 年龄/地球化学/Sr-Nd 同位素/花岗岩/塔山-阳明山地区/湖南Key words
zircon U-Pb age/geochemistry/Sr-Nd isptopes/Tashan-Yangmingshan/granite/Hunan province引用本文复制引用
马丽艳,刘树生,付建明,程顺波,卢友月,梅玉萍..湖南塔山、阳明山花岗岩的岩石成因：来自锆石 U-Pb 年龄、地球化学及 Sr-Nd 同位素证据[J].地质学报,2016,90(2):284-303,20.基金项目
本文为中国地质调查项目（12120114020701）及地质矿产调查评价项目（1212011120804）资助的成果。 （）
