DIFFUSION, REACTION AND FLOW PHENOMENA RELATED TO PATTERN FORMATION IN ROCKS

(1)蛇形底辟海山的模拟将产于伊豆-小川-马里亚纳前弧的蛇形底辟模拟为来自楔形地幔的蛇形底辟。在观测和模拟的基础上，讨论了海山发育的时间和空间尺度。推测由于SiO_2和H_2O的扩散补给，楔形地幔底层发生了蛇纹状岩化。利用底辟形成理论，利用底辟间距与蛇纹岩与地幔粘性比之间的关系，估算出蛇纹岩层的厚度约为10米。(2)花岗岩体系熔融实验和花岗岩熔体中扩散系数的测定。钠长石单晶和石英粉等熔融对之间形成了较薄的熔体层。熔化层的厚度服从抛物线生长速率定律，表明扩散限制了熔化层的生长。最慢组分(速率决定组分)的扩散系数由抛物线生长定律估算。

(1) Modeling of serpentine diapirSerpentine seamounts which occur in the Izu - Ogasawara- Mariana forearcs are modeled as serpentine diapir from the wedge mantle. The time and space scale of the development of seamounts were discussed based on observations and modeling. Serpentinization of the bottom layer of the wedge mantle due to diffusive supply of SiO2 and H2O is assumed. The thickness of the serpentinized layer is estimated to be the order of 10 meters by employing theory of diapir formation using the relation between the spacing of diapirs and viscosity ratio of serpentinite and the mantle.(2) Melting experiments in granitic system and measurements of diffusion coefficients in the granitic melts.Non-equilibrium melting experiments at temperatures above the eutectic point were carried out in granitic system to simulate natural melting phenomena in migmatite experimentally. Thin melt layers were formed between melting couples such as albite single crystal and quartz powder. The thickness of the melt layer obeys the parabolic growth rate law, suggesting diffusion limited growth of the layer. Diffusion coefficient of the slowest component (rate - determining component ) is estimated by the parabolic growth rate law.