四川中咱地块冈达概组火山岩石地球化学特征及成因  

Geochemical Characteristics and Genesis of the Volcanic Rocks of the Gangdagai Formation in the Zhongza Massif,Sichuan

作　　者：贾志泉[1] 郝娇 胡许 杨立 JIA Zhi-quan;HAO Jiao;HU Xu;YANG Li(No.108 Geological Team,BGEEMRSP,Chengdu 611230)

机构地区：[1]四川省地质矿产勘查开发局一0八地质队,四川崇州611230

出　　处：《四川地质学报》2020年第4期686-689,共4页Acta Geologica Sichuan

摘　　要：中咱地块冈达概组(P2g)分布于金沙江蛇绿混杂岩带与沙鲁里-义敦岛弧带之间的中咱-中甸地块上,北至茨巫,南至小中甸一带,本文研究对玄武岩进行研究,取得了新的认识,进一步探讨了中咱地块区冈达概组(P2g)玄武岩岩石特征及构造背景[1,2]。其岩性由玄武质火山角砾岩(玄武质火山集块岩),致密块状玄武岩、杏仁状玄武岩、气孔状玄武岩、玄武质质角砾岩屑凝灰岩、硅质岩组成。玄武岩具低K2O、Na2O,高CaO、FeO的特征,属低钾系列;TiO2相对较高,是地幔低度熔融的产物,属板内张裂型火山岩。The Gangdagai Formation(P2g)in the Zhongza massif is exposed in the Zhongza-Zhongdian massif between the Jinsha River ophiolitic mélange zone and the Shaluli-Yidun island arc zone.This paper further discusses the petrological characteristics and tectonic setting of the basalt of the Gangdagai Formation(P2g)in the Zhongza massif.The study indicates that the basalt consists of basaltic volcanic breccia(agglomerate),dense massive basalt,amygdaloidal basalt,porous basalt,basaltic breccia lithic tuff and siliceous rock.The basalt is characterized by low K 2O and Na2O,high CaO and FeO,relatively high TiO2 which shows origin of low melting of mantle of the basalt,being an intraplate tensional volcanic rock.

关 键 词：中咱地块 冈达概组 玄武岩 岩石地球化学 地幔柱 

分 类 号：P588.14[天文地球—岩石学]