Petrogenesis and Geochronology of the High Ba-Sr Kaobeijian Granodiorite Porphyry, Jixi County, South Anhui Province
详细信息
- 责任者：Zhou Xiang (School of Earth Sciences and Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yu Xinqi
- 刊名：Acta Petrologica Sinica
- 出版年：2012
- 卷期：28(10)
- 关键词：花岗闪长斑岩 ; granodiorite porphyry ; 钡 ; barium ; 锶 ; strontium ; 安徽 ; Anhui Province
- 页码：p.3403-3417
- 图表：illus., 3 tables, 84 refs.
- 分类号：0801
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
The Kaobeijian granodiorite porphyry,outcrop area of 0.7 km2, is a small stock which intruded into Neoproterozoic-Paleozoic marine sedimentary strata in Jixi County, South Anhui Province. The unusual high Ba-Sr composition comes from Neoproterozoic granodiorites which was enriched of Ba-Sr.The mantle-derived materials likely played an important role in the generation of the magma,letting the S-type magma gradually transformed into I-type magma in mixing process.In addition,lots of felsic-quartz veins and hydrothermal alteration indicate that the stock had been underwent an intensively residual melting and/or hydrothermal fluid activities.All these indicate that pervious 40Ar/39Ar age of (134.3±1.4) Ma for biotite from the Kaobeijian granodiorite porphyry is more likely to document a tectonic-thermal event,rather than the forming age of the rock.SHRIMP zircon U-Pb analyses yield consistent ages of (151.9±1.1) Ma,(152.9±1.1) Ma and (147.7±1.3) Ma for three samples of granodiorite,indicate the magma was emplaced in Late Jurassic.