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在马萨诸塞州亚当斯市 Pfizer 采石场采集的富方解石 Shelburne 大理岩样品,在颗粒粒度上呈现量级变化序列。方解石的颗粒粒度范围为94~1101μm。由于这些方解石大理岩都是同温、同压、同应变条件下生成的,因此肯定有一些其它因素导致了颗粒粒度的不同。颗粒粒度显示出受杂质密集度或次生相颗粒控制。在次生相颗粒体积分数小的地方出现大的方解石颗粒,且其粒度随次生相体积分数的增大而减小。方解石颗粒粒度(D)、次生相颗粒粒度(d)和次生相体积分数(f)之间的关系可用指数定律 D/d=1.4/f~(0.36)来表达,此结论与用金属和陶瓷做的短期(几小时或几天)实验室实验和计算机模拟所得结果一致。颗粒生长很大程度上只受极少百分点次生相颗粒的限制,在次生相体积分数约等于5%时,颗粒生长由高度限制突变为几乎不受其限制。这些结论都表明,变质岩中次生相颗粒在控制颗粒生长方面起重要作用,可有效地制约颗粒生长。实验室实验中短期的次生相颗粒行为接近于变质环境下持续了几个量级序列的颗粒生长中的次生相行为。
The calcite-rich Shelburne marble samples collected at the Pfizer quarry in Adams, Massachusetts, present order-of-magnitude variation in particle size. The particle size of calcite ranged from 94 to 1101 μm. Since all these calcite and marble are formed at the same temperature and at the same pressure and with the same strain, there are certainly some other factors that cause the difference in grain size. Particle size shows impurity concentration or secondary phase particle control. Large particles of calcite appear in the place where the volume fraction of the secondary phase particles is small, and the particle size decreases with the increase of the secondary phase volume fraction. The relationship between calcite particle size (D), secondary particle size (d) and secondary phase volume fraction (f) can be expressed by the exponential law D / d = 1.4 / f ~ And ceramic short (a few hours or days) laboratory experiments and computer simulation results obtained. Particle growth is limited to a very small percentage of virgin grains to a large extent, and when the secondary phase volume fraction is about 5%, the grain growth is mutated from a highly restricted to a barely bound. All of these conclusions indicate that the secondary particles in the metamorphic rocks play an important role in controlling the grain growth, which can effectively restrain the grain growth. The short-term secondary phase particle behavior in laboratory experiments is close to the secondary phase behavior in grain growth that lasted several orders of magnitude in the metamorphic environment.