Petrogenesis and Tectonic Setting of the K-feldspar Granites in Chaihe Area, Central Greater Xing’ an Range: Constraints from Petro-geochemistry and Zircon U-Pb Isotope Chronology
详细信息
- 责任者：Wang XingAn(College of Earth Sciences ; Jilin University ; Changchun 130061 ; China) ; Xu ZhongYuan
- 刊名：Acta Petrologica Sinica
- 出版年：2012
- 卷期：28(8)
- 关键词：A型花岗岩 ; A-type granite ; 大兴安岭 ; Greater Hinggan Mountains
- 页码：p.2647-2655
- 图表：illus.,2 tables,42 refs.
- 分类号：0801
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
mal; ORPHANS: 2; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">In this paper, the geochemistry and zircon U-Pb isotope chronology of the Chaihe K-feldspar granites in the central Greater Xing’an Range is studied and their petrogenesis and tectonic significance are discussed. The zircons from Chaihe K-feldspar granites show oscillatory growth zonations of typical magmatic origin and high Th/U ratios (0.52~1.33), indicating a magmatic origin for the zircons, and yielded a LA-ICP-MS U-Pb age of 133±3Ma. The granites have high SiOmal; FONT-STYLE: normal; TEXT-INDENT: 0px; FONT-FAMILY: ����,verdana; WHITE-SPACE: normal; ORPHANS: 2; LETTER-SPACING: normal; COLOR: rgb(0,0,0); FONT-WEIGHT: normal; WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">2mal; ORPHANS: 2; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px"> rare earth elements (REE), high field-strength elements (HFSE), and large ion lithophile elements (LILE) contents. The REE patterns are characterized by enrichment of LREEs relative to HREEs and distinct negative Eu anomalies in chondrite-normalized REE diagram, which is characterized by right oblique and "V"-shaped feature. These features suggest that the Chaihe K-feldspar granites belong to aluminous A-type granite which derived from partial melting of crustal rocks with a typical character of Amal; FONT-STYLE: normal; TEXT-INDENT: 0px; FONT-FAMILY: ����,verdana; WHITE-SPACE: normal; ORPHANS: 2; LETTER-SPACING: normal; COLOR: rgb(0,0,0); FONT-WEIGHT: normal; WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">1mal; ORPHANS: 2; FLOAT: none; LETTER-SPACING: normal; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px">-type (rift valley or within plate) granite representing an extensional tectonic environment.