主要造岩矿物动态重结晶作用及其变质条件

动态重结晶是一种重要的矿物变形作用,主要包括膨凸、亚晶粒旋转和颗粒边界迁移重结晶作用三种变形机制。随着变质程度的不断增强,膨凸、亚晶粒旋转和颗粒边界迁移重结晶作用顺次出现。动态重结晶作用是温度、压力、应力以及流体等多方面综合作用的结果,而不仅仅与变形温度有关,因此我们认为以变质相带代替温度变化作为主要造岩矿物动态重结晶机制的转变条件应该更为合理。通过大量薄片观察和综合分析,我们概述了不同变质相条件下主要造岩矿物的变形特征组合,并提出了主要造岩矿物的动态重结晶发生的相对顺序大致应为方解石→黑云母→石英→长石→角闪石→橄榄石→辉石,与前人有所不同。

Dynamic recrystallization and metamorphic conditions of main rock-forming minerals.

Dynamic recrystallization is an important mechanism during the deformation of minerals, and it involves three kinds of different mechanisms, namely, bulging, subgrain rotation and grain boundary migration recrystallization. All these three different mechanisms may occur sequentially with the strengthening of the metamorphic condition, resulting from the synthetical action of temperature, pressure, stress and fluids. The authors indicate that it is reasonable to consider the metamorphic facies instead of the temperature as the transitional conditions for main rock-forming minerals. Based on the observation and analysis of main rock- forming minerals, we present in this article the relatively sequence and metamorphic conditions of their dynamic recrystallization. From brittle to ductile condition, the dynamic recrystallization sequence is calcite→biotite→quartz→feldspar→hornblende→olivine→pyroxenes.