【作者】 葛良胜； 郭晓东； 邹依林； 李振华； 邢俊兵；

【Author】 GE Liang-sheng, GUO Xiao-dong, ZOU Yi-lin, LI Zhen-hua, XING Jun-bing (Geological institute of the Armed police forces , Lang fang 065000, China)

【机构】 武警黄金地质研究所；

【摘要】 滇西北地区广泛分布以富碱为特点的岩浆岩。这些富碱岩体(脉)主要形成于50-30Ma,由区内近平行分布的近EW向构造控制,空间上可以划分为多个近EW岩带,各岩带内又可划分为多个岩体(脉)集中区;富碱岩体(脉)由正长(斑)岩、二长斑岩、花岗斑岩及相关的火山岩组成,具有多次活动的特征,是由同源演化产物组成的富有特色的岩浆岩系列。微量元素、稀土元素、同位素等地球化学特征的研究表明,岩体产出于经多次板块开合作用之后形成的统一但不稳定的陆块内部、古深大断裂于喜山期重新活动引发的张性环境中,岩浆源于壳幔混合带,是地幔富碱质流体经由深断裂上升至混合带内并引发该区岩石部分熔融的产物。更多还原

【Abstract】 In the northaest Yunnan province are widely distributed alkali-rich rock bodies formed during the period of 50-30 Ma and controled by roughly E-W oriented structure. Spatially the bodies are grouped into several roughly E-W oriented belts. Each belt can be divided into several mtrussive-concentrated areas. The rock bodies are composed of syenitic porphyry, monzonitic porphyry and related volcanics characterized by multi-activities and cognate magmatism. Studies on micro-element. REE, H , O, S, Pb, Rb-Sr, Sm-Nd isotopes show that the bodies were formed in a unstable amalgamated continental plate after multi ply divergent and convergent plate movements. Under tensional envioronment caused by the reactivated deep-seated fracture during Himalaya period the alkali-rich magma was derived from the mixed zone of crust and mantle and formed by partial melting of the country rock during upgoing of the maga along the, deep-seated fracture.更多还原