INTERNAL STRUCTURE OF KUTSUGATA LAVA FLOW, RISHIRI VOLCANO
INTERNAL STRUCTURE OF KUTSUGATA LAVA FLOW, RISHIRI VOLCANO
复制标题
利尻火山 KUTSUGATA 熔岩流的内部结构
DOI：
10.2465/ganko1941.76.181
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Yasuteru Kawasaki
中科院分区：
文献类型：
--
作者：
Takeyoshi Yoshida;Teruhiko Yamaguchi;Yasuteru Kawasaki
在Rishiri火山Kutsugata熔岩流中识别出三种类型的泡状分离体，即“分离层”、“分离柱”和“分离股”。在横截面上。偏析层为几毫米至十多厘米厚的平铺平行带状组织。分离筒为细长立柱，与柱上端的分离层相连。分离料被定义为从宿主熔岩中分离出来的脉冲或脉冲，并与分离层相关联。这些深色的分离体一定是在平地上停止移动的熔岩裂隙的固结过程中形成的，按照一定的顺序，首先是分离层，然后是分离圆柱体，最后是分离物。在玄武岩岩浆冷却过程中，结晶颗粒和残留的气泡流体组成了分散的或有框架的盐液系统。现场证据表明，偏析层来自于骨架固液复合体中垂直于东向主应力方向发育的伸展裂缝。然而，偏析是由于固液体系的触变破晓和应力硬化的释放而产生的。认为Kutsugata 1ava井存在三种物质输运机制，即伸展裂隙中粘性液体的流动、三相渗流体系中的孔道流动和低密度塑性块的底辟上升。为了追踪岩浆挤压后的分馏趋势，对分离体的8种化学分析与典型厚熔岩流中的6种主体进行了比较，并与里希里火山所有已发表的块状岩石分析进行了比较。
Three types of vesicular segregated bodies are recognized in the Kutsugata lava flows, Rishiri Volcano; namely, “segregation layer”, “segregation cylinder”, and “segregation stock”. In transverse section. the segregation layer is a flat-lying parallel banding from several mm to more than 10cm thick. The segregation cylinder is a slender vertical column which is connected with the segregation layer at the upper end of the column. The segregation stock is defined as a pulge or pulme segregated from the host lava, and is associated with the segregation layer. These dark-colored segregated bodies must have formed during consolidation of the lava flaws which had ceased to move on the flat ground, in the definite sequence with segregation layers first, then segregation cylinders and finally segregation stocks. During cooling of basaltic magma, crystal particles and residual 1iquid with bubbles must have composed a dispersed or framewarked salid-fluid system. The field evidence suggests that the segregation layer was derived from the extension fracture developed perpendicular to the 1east principa1 stress direction in the frameworked so1id-fluidcomp1ex. The segregation cy1inde and stock, however, must have originated in the f1ow by the thixotropic break dawn and the release of stress-hardening of the solid-fluid system. It is considered that there were three mechanisms of material transport in the Kutsugata 1ava f1ows, viz., f1ow of a viscous 1iquid in the extensioh fractures, vo1ati1e channel1ing in the three-phase f1uidized system, and diapiric uprise of low density plastic masses. Eight chemica-analyses of the segregated bodies are compared with six from their hostparts in a typical thick lava flow together with all published bulk rock analyses from the Rishiri Volcano in order to trace fractionation trends of the magma after extrusion.