岩浆驱动破裂的形态研究  

The shape study of magma driven crack

作　　者：栾锡武[1] 秦蕴珊[1] 宋海斌[2] 石耀霖[3] 

机构地区：[1]中国科学院海洋研究所,青岛266071 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国科学院研究生院,北京100039

出　　处：《地球物理学进展》2003年第1期138-141,共4页Progress in Geophysics

基　　金：大洋"十五"项目 (DY10 5 0 1 0 1 6);国家自然科学基金项目 ( 4 0 0 0 60 0 4);国家重点发展规划项目 (G2 0 0 0 0 4670 3 0 3 )联合资助 .

摘　　要：轴地壳岩浆房是活动扩张中心海洋地壳结构的一个重要组成部分 ,轴地壳岩浆房通过深部岩浆源的补充 ,内部岩浆的同化熔融、结晶分异等岩浆房过程 ,其中的岩浆会破裂上覆的岩石层形成岩浆破裂 ,并沿岩浆破裂继续向上迁移 .本文建立了岩浆迁移的层流模型 ,从理论上对岩浆迁移问题进行了探讨 ,并将遗传算法引入到该问题中来 ,用遗传算法求解了描述岩浆驱动破裂传播的积分方程 .如果假设岩浆破裂在远离破裂末梢处的极限宽度为 1m ,则靠近末梢 ,破裂的宽度逐渐加大 ,在末梢处宽度为 2m左右 .并根据文献对岩浆流体的一些观测参数计算得出 ,岩浆破裂极限宽度不会很大 ,一般在 1m左右的量级 .Axies magma chamber(AMC) is one of the most important part of oceanic crust in the active spreading center. Once the magma reaches to the AMC from the deep magma reservoir, the segregated magma will break the upper layer and continually migrated towards the surface driven by the buoyancy. The magma driven crack formed in this progress. Based on the Boussinesq model, the problem of magma crack migration was discussed in this paper and the Genetic Algorithm was used to calculated the shape of the magma driven crack. Assume the limited width far from the crack tip is 1, the width of the crack becomes lager and lager as coming near to the crack tip and reaches almost 2 at the tip. Based on the measured parameters of magma fluid given by references, the paper points that the limited width of the magma driven crack is about 1 meter.

关 键 词：轴地壳岩浆房 岩浆驱动破裂 遗传算法 破裂形态 

分 类 号：P313[天文地球—固体地球物理学]