辽西义县许家屯巨型枕状熔岩地质特征  

GEOLOGICAL CHARACTERISTICS OF THE XUJIATUN GIGANTIC PILLOW LAVA IN YIXIAN COUNTY,WESTERN LIAONING PROVINCE

作　　者：李之彤[1] 杨芳林[1] 

机构地区：[1]沈阳地质矿产研究所,辽宁沈阳110033

出　　处：《地质与资源》2007年第1期12-15,共4页Geology and Resources

摘　　要：辽西义县许家屯巨型枕状熔岩产在义县旋回第二亚旋回火山岩沉积夹层中.以其岩枕巨大(5～8m)、形态多样构成独特的火山岩景观.岩枕大体由冷凝边、过渡带和核部3部分组成,三者间在颜色、气孔和杏仁的数量与大小上彼此有别.它们的岩石学、地球化学特征完全可以和下伏火山岩对比,岩性属玄武安山岩.其是在第二亚旋回火山活动间歇期,岩浆再次溢出,涌流进水体(如湖泊)里冷凝而成为陆相环境产物,与海相玄武质枕状熔岩明显不同.The Xujiatun gigantic pillow lava in Yixian County of Western Liaoning occurs in the sedimentary interbed of volcanic rocks, which belong to the second subcycle of Yixian cycle. The gigantic pillow lava, characterized by huge pillow bodies （5 to 8 m） and diverse shapes, constitutes a distinctive landscape of volcanic rocks. Each pillow body is generally composed of three parts, i.e. chilled border, transitional belt and core, which distinguish each other in their colors, quantity and size of vesicles and amygdales. Belonging to basaltic andesite, the pillow lava could be petrologically and geochemically compared with the underlying volcanic rocks. The pillow lava was formed as a result of condensation of magma in lake, when it effused again during the intermittent of volcanic activity in the second subcycle. It belongs to continental volcanic rock, which is obviously different from marine basaltic pillow lava.

关 键 词：巨型枕状熔岩 陆相环境 义县旋回火山岩 辽西义县许家屯 

分 类 号：P588.14[天文地球—岩石学]