福建镇海一带玄武岩柱状节理的动力学研究：兼论柱状节理的成因

根据流体动力学和自组织理论,研究了玄武岩柱状节理形成的动力学特征,并应用福建镇海一带玄武岩平均化学成分,估算出动力学方程中所涉及的参数,求出了断面直径与节理柱体长度之间的函数关系,并用数值计算方法,求出了R_a,d和L的值,其结果与该地区的地质实际基本吻合,最后探讨了柱状节理的成因机理,并把柱状节理的形成过程划分为两个阶段:(1)热耗散-对流阶段,(2)冷却-收缩阶段。

DYNAMICS OF COLUMNAR JOINTS IN BASALT, ZHENHAI AREA, FUJIAN PROVINCE, WITH SPECIAL REFERENCE TO ITS GENESIS

In the paper, based on fluid dynamics and self-organization theory, dynamical characteristics of columnar joints in basalt are studied and all parameters of dynamical equations are calculated according to the mean chemical compositions of basalt in Zhenhai, Fujian Province. We have found the functional relation between the thickness and section diameter of columnar joints; moreover, the result of digital simulation of dynamical equations is consistent with the local geological conclusion. Finally, we have also probed into the genesis of columnar joints and divided the process of the formation of columnar joints into two stages: (1) thermo-dissipative-eonvection stage and (2) cooling-contraction stage.