龙岗火山喷发特征与火山岩岩石化学初步研究

A Preliminary Study of Eruption Features and Petrochemistry of Volcanic Rocks from the Longgang Volcanoes

龙岗火山是中国少数几个近代仍有喷发的活动火山区之一,在1700多平方千米火山区内形成100多个玄武质岩浆爆炸成因的火山锥和低平火口湖(龙湾),并有约1600aBP喷发的金龙顶子活火山。龙岗火山岩是单一的粗面玄武岩,具有一致的化学成分,表明岩浆上升过程中很少演化,推测龙岗火山岩来自同源地幔岩浆。

The Longgang volcanic region is one of the few regions with recent volcanic activities in Ch na. There are over a hundred volcanic cones and maars of an explosive genesis of basaltic magma in the area of 1700 km^2. There is also the Jinlongdingzi active volcano, which erupted 1600 a BP. The Longgong volcanic rocks are trachybasalts with homogeneous petrochemical compositions. This indicates that there has been little evolution during their ascending processes, and that they may be derived from comagmatic magma of the mantle.