Non-stoichiometry of interlayer cations in micas from low- to middle-grade metamorphic rocks in the Ryoke and the Sanbagawa belts,Japan     

Ge -Fan Wang  Shohei Banno 《Contributions to Mineralogy and Petrology》1987,97(3):313-319

Micas in 17 pelitic (K-feldspar-free) and 8 psammitic (K-feldspar-bearing) rocks from the Wazuka and the Asemi-gawa areas in the Ryoke and the Sanbagawa metamorphic terrains, respectively, were analyzed on an electron-probe microanalyzer. The deficiency of alkali cations in the low- to middle-grade metamorphic micas is ascribed to the illite substitution, K^XII+Al^IV=^XII (vacancy)+Si^IV.At the same metamorphic grade, the deficiency of interlayer cations in micas from the pelitic rocks is greater than that from the psammitic rocks. However, it decreases with rising temperature in both rock-types, irrespective of the pressure of metamorphism.K-feldspar and biotite buffer the illite substitution. Two reactions are proposed to explain the decrease of the alkali-cation deficiency in both muscovite and biotite.  相似文献   

Petrology of peridotite and garnet clinopyroxenite of the Mt. Higasi-Akaisi mass,central Sikoku,Japan — Subsolidus relation of anhydrous phases     

Takeshi Mori  Shohei Banno 《Contributions to Mineralogy and Petrology》1973,41(4):301-323

The mineralogy of anhydrous minerals of peridotite and garnet clinopyroxenite of the Mt. Higasi-Akaisi peridotite mass, Japan, is described. The subsolidus equilibria among garnet, clinopyroxene, orthopyroxene and olivine are discussed in terms of composition range of solid solutions and of Fe-Mg partition. It is concluded that the anydrous minerals of this mass equilibrated at lower temperatures than any of well studied peridotite-garnet clinopyroxenite association. The tentative estimation gives 5–600° C and 7–13 Kb as the physical conditions of equilibration. Comparison with similar associations from other occurrences and geological implications are briefly discussed.  相似文献   

山东海阳所麻粒岩向过渡榴辉岩转化的变质动力学过程及其构造意义   总被引：2，自引：2，他引：0  

叶凯  平岛崇男 《岩石学报》1999,15(1):21-36

在山东半岛东南端的乳山海阳所,角闪岩和长英质片麻岩呈互层产出,在某些角闪岩层的中心残留有弱变形的麻粒岩和强变形的过渡榴辉岩（斜长石榴辉岩）团块,在弱变形的麻粒岩团块中发育有窄的（〈１ｃｍ）剪切条带,沿着这些剪切条带和强变形过渡榴辉岩团块中,原麻粒岩被转化为含斜长石的过渡榴辉岩。变形和流体在这一转化过程中加速了元素扩散和迁移的速度,在变形强和有流体加入的部位麻粒岩向榴辉岩转化的程度明显增强,麻粒岩相  相似文献   

Significance of shape factor on permeability anisotropy of sand: representative elementary volume study for pore-scale analysis     

Katagiri  Jun  Kimura  Sho  Noda  Shohei 《Acta Geotechnica》2020,15(8):2195-2203

Acta Geotechnica - This paper is a study of determination of representative elementary volume (REV) size suitable for pore-scale flow simulation (PFS) and evaluation of permeability anisotropy for...  相似文献