Superplasticity in garnet from eclogite facies shear zones in the Haram Gabbro, Haramsøya, Norway
Superplasticity in garnet from eclogite facies shear zones in the Haram Gabbro, Haramsøya, Norway
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挪威Haramsøya Haram Gabbro 榴辉岩相剪切带中石榴石的超塑性
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
F. Heidelbach
中科院分区：
文献类型：
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作者：
M. Terry;F. Heidelbach
对同运动榴辉岩化剪切带附近和内部的石榴石进行了研究，揭示了石榴石的微结构和结构，首次表明晶界滑动是石榴石的主要变形机制。单矿物石榴石层表现出超塑性行为的特征，与周围矿物强度对比不大。强度较低的原因是石榴石的共生生长，使其颗粒尺寸限制在几十微米。这种行为可能显著影响俯冲环境中高压和超高压剪切带的流变性，并可能在地幔过渡带石榴石的形成过程中发挥作用。
Study of garnet adjacent to and within shear zones that underwent synkinematic eclogitization reveals microstructures and textures that, for the first time, indicate grain- boundary sliding as the main deformation mechanism in garnet. Monomineralic garnet layers exhibit characteristic features of superplastic behavior and show little strength contrast to the surrounding minerals. The low strength is caused by the synkinematic growth of garnet limiting the grain size to tens of micrometers. This behavior may significantly influence rheologic properties of high- and ultrahigh-pressure shear zones in subduction environments and may play a role during the formation of garnet in the transition zone of the mantle.