摘要
位于贝加尔裂谷带西南端通京盆地的尚加泰火山玄武岩由高拉长石—中长石、贵橄榄石、次透辉石、火山玻璃组成,据对S iO2与全碱(N a2O+K2O)的关系判断,均为碱性橄榄玄武岩,微量元素、稀土元素分布型式与板内碱性玄武岩一致,推测原始岩浆来源于上地幔距地表200 km^250 km深度处,在距地表约40 km处即莫霍面附近开始冷却结晶,该火山活动区可能成因于异常地幔凸起中的物质-能量流沿着断裂在通京盆地内的上升。
Sunjardy volcano in Tunka basin in the Southwestern of Baikal rift belt is composed of chrysolite,labradorstein-andesine,salite and volcanic glasses. The basalts belong to alkalic series revealed by the composition of w（SiO2） vs w（Na2O＋K2O）. Trace elements and REEs distribution patterns are the same as WPB. It is concluded that the primitive magmas comes from upper mantle which is about 200 km;250 km beneath the earth surface ,and the porphyritic crystals might be crystallized at 40 km beneath the Earth surface. It is considered that the volcanic activity may be related to the uplifted flow of matter-energy in the ataxinomic mantle.
出处
《矿物岩石》
CAS
CSCD
北大核心
2006年第3期56-63,共8页
Mineralogy and Petrology
基金
国家地质学理科基地人才培养基金
