【摘要】：幔源玄武巖及地幔捕虜體中所含的地幔流體揮發(fā)分對于認(rèn)識巖漿源區(qū)特征及巖石圈地幔演化具有重要意義。本文對東北地區(qū)雙遼新生代玄武巖及其攜帶的地幔捕虜體中流體揮發(fā)分進行研究,探究地幔流體特征與來源。雙遼玄武巖橄欖石斑晶和地幔捕虜體內(nèi)發(fā)育早期、晚期兩類流體包裹體,早期流體包裹體中的揮發(fā)分代表礦物形成時捕獲的巖漿原始流體揮發(fā)分,主要在高溫段(600~1200℃)釋出,晚期流體包裹體中的揮發(fā)分代表礦物形成后捕獲的交代或蝕變流體揮發(fā)分,主要在低溫段(200~600℃)釋出。地幔捕虜體原始流體揮發(fā)分主要為H_2O、CO和H_2,其次為CO_2,并含有少量CH_4等烴類。地幔捕虜體交代流體揮發(fā)分與雙遼玄武巖橄欖石斑晶原始流體揮發(fā)分相似,主要為CO_2和H_2O,其次為CO和H_2,含有少量烴類。地幔捕虜體原始流體揮發(fā)分、交代流體揮發(fā)分及玄武巖橄欖石斑晶原始流體揮發(fā)分中,CO_2和烴類碳同位素均具有有機成因特征,表明巖石圈地幔及玄武巖巖漿源區(qū)內(nèi)均存在有機質(zhì)熱解產(chǎn)物的混入,玄武巖巖漿源區(qū)及巖石圈地幔交代流體中的有機成因揮發(fā)分主要來自于俯沖太平洋板片之上的沉積有機質(zhì)。雙遼玄武巖斜長石斑晶和基質(zhì)流體揮發(fā)分含量較高,主要為H_2O和CO_2,相對于橄欖石原始流體揮發(fā)分具有較輕的CO_2碳同位素組成,這種現(xiàn)象表明巖漿上升過程中發(fā)生了明顯的脫氣作用。
[Abstract]:The volatilization of mantle fluid in mantle basalt and mantle xenoliths is of great significance in understanding the characteristics of magmatic source region and the evolution of lithospheric mantle. In this paper, the characteristics and sources of fluid volatilization in the Cenozoic basalt of Shuangliao and its mantle xenoliths in Northeast China are studied. Early and late fluid inclusions developed in olivine porphyry and mantle xenoliths of Shuangliao basalts. The volatiles in early fluid inclusions represent the volatile matter of magmatic primitive fluids captured during the formation of minerals, which are mainly released at high temperature (600 ~ 1200 鈩，

本文編號：2250662