Characteristic mineralogy of the Zhutishi granite:Implication for petrogenesis of the late intrusive granite  

作　　者：WANG Xiang YAO Xiaojuan WANG Chuansheng 

机构地区：[1]State Key Laboratory for Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China State Key Laboratory for Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China State Key Laboratory for Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China

出　　处：《Science China Earth Sciences》2006年第6期573-583,共11页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.40172023,40132010 and 40572038).

摘　　要：Many late intrusive granites with strongly peraluminous composition and fine-grained tex-ture occur as stocks or apophysis in the Dadongshan main intrusive granite located in NW Guang-dong Province. This paper reports the results of a petrogenetic study of some characteristic minerals (zircon, muscovite and andalusite) from the Zhutishi granite, one of the late intrusive granites in the Dadongshan granite. It is observed that the typological pattern of zircon population in the Zhutishi granite differs significantly from that in the Dadongshan granite, and that muscovite and andalusite, only found in the Zhutishi granite, are of magmatic origin. Therefore, this paper considers that the Zhutishi granite was unlike to be produced through crystal fractionation from the Dadongshan granitic magma as reported by previous authors, but is related closely to the formation of the Dadongshan granite. The hydrothermal fluid, produced by differentiation of the Dadongshan granitic magma at deep magmatic chamber, would penetrate into the source rock of the Zhutishi granite, and make it enriched in H2O and Al2O3; and the decompression after the ascent of the Dadongshan granitic magma in extension regime promotes partial melting of the source rock of the Zhutishi granite, and produces the strongly peraluminous granitic magma. The model proposed in this paper seems to be more reasonable to explain the spacio-temporal relationship between the late intrusive granites with strongly peraluminous feature and the main intrusive granite with metaluminous feature.Many late intrusive granites with strongly peraluminous composition andfine-grained texture occur as stocks or apophysis in the Dadongshan main intrusive granite locatedin NW Guangdong Province. This paper reports the results of a petrogenetic study of somecharacteristic minerals (zircon, muscovite and andalusite) from the Zhutishi granite, one of thelate intrusive granites in the Dadongshan granite. It is observed that the typological pattern ofzircon population in the Zhutishi granite differs significantly from that in the Dadongshan granite,and that muscovite and andalusite, only found in the Zhutishi granite, are of magmatic origin.Therefore, this paper considers that the Zhutishi granite was unlike to be produced through crystalfractionation from the Dadongshan granitic magma as reported by previous authors, but is relatedclosely to the formation of the Dadongshan granite. The hydrothermal fluid, produced bydifferentiation of the Dadongshan granitic magma at deep magmatic chamber, would penetrate into thesource rock of the Zhutishi granite, and make it enriched in H_2O and Al_2O_3; and the decompressionafter the ascent of the Dadongshan granitic magma in extension regime promotes partial melting ofthe source rock of the Zhutishi granite, and produces the strongly peraluminous granitic magma. Themodel proposed in this paper seems to be more reasonable to explain the spacio-temporal relationshipbetween the late intrusive granites with strongly peraluminous feature and the main intrusivegranite with metaluminous feature.

关 键 词：LATE INTRUSIVE granite  main INTRUSIVE granite  zircon  muscovite  andalusite. 

分 类 号：N[自然科学总论]