当前位置: X-MOL 学术J. Struct. Geol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Evolution of stretching lineations in granulite-hosted ductile shear zones, Eastern Ghats Province, India: Role of temperature, strain rate and pre-existing stretching lineations
Journal of Structural Geology ( IF 2.6 ) Pub Date : 2020-09-01 , DOI: 10.1016/j.jsg.2020.104127
Subham Bose , Saibal Gupta

Abstract Shear zone kinematics are interpreted from sections (X-Z) parallel to the stretching lineation (X-direction) and perpendicular to the mylonitic foliation (X–Y). The stretching lineation is a product of finite strain, defined by minerals or mineral aggregates that deform plastically. In quartzofeldspathic rocks deformed below 600 °C, rheological contrasts between quartz and feldspar are amplified, and the mesoscopic stretching lineation in the shears may be indistinct in outcrop as quartz ribbons anastomose around relatively competent feldspar clasts. In high strain-rate zones, rheological contrasts between these minerals are reduced and a stretching lineation suitable for kinematic interpretation develops. In late amphibolite and greenschist facies shear zones transecting pre-lineated quartzofeldspathic granulites of the Eastern Ghats Province, India, the stretching lineation represents the resultant of pre-existing stretch and superposed increments of later shearing. Until the stretch accumulated in the X-direction of the later deformation exceeds the earlier finite stretch, the pre-existing stretching lineation progressively rotates towards the later X-direction with decreasing aspect ratio. These intermediate lineation orientations, have no kinematic relevance to either earlier or later deformations. This example highlights the importance of temperature, strain rate and orientation of pre-existing stretching lineations in the appearance and kinematic interpretation of,stretching lineations in ductile shear zones.

中文翻译:

印度东高止山脉麻粒岩承载的韧性剪切带中拉伸线的演化:温度、应变率和预先存在的拉伸线的作用

摘要 剪切带运动学是从平行于拉伸线(X 方向)和垂直于糜棱片理(X-Y)的截面(XZ)解释的。拉伸线纹是有限应变的产物,由塑性变形的矿物或矿物聚集体定义。在 600 °C 以下变形的石英长石岩中,石英和长石之间的流变对比被放大,由于石英带在相对有力的长石碎屑周围吻合,因此剪切中的细观拉伸线理可能在露头中模糊不清。在高应变率区域,这些矿物之间的流变对比降低,并且适合运动学解释的拉伸线形发展。在横切印度东高止山脉预线状石英长石麻粒岩的晚期角闪岩和绿片岩相剪切带中,拉伸线状是预先存在的拉伸和后期剪切叠加增量的结果。直到后期变形的 X 方向累积的拉伸超过早期的有限拉伸,预先存在的拉伸线条逐渐向后期 X 方向旋转,纵横比减小。这些中间线状取向与早期或晚期变形没有运动学相关性。这个例子强调了温度、应变率和预先存在的拉伸线的方向在韧性剪切区拉伸线的外观和运动学解释中的重要性。拉伸纹路代表了预先存在的拉伸和后期剪切叠加增量的结果。直到后期变形的 X 方向累积的拉伸超过早期的有限拉伸,预先存在的拉伸线条逐渐向后期 X 方向旋转,纵横比减小。这些中间线状取向与早期或晚期变形没有运动学相关性。这个例子强调了温度、应变率和预先存在的拉伸线的方向在韧性剪切区拉伸线的外观和运动学解释中的重要性。拉伸纹路代表了预先存在的拉伸和后期剪切叠加增量的结果。直到后期变形的 X 方向累积的拉伸超过早期的有限拉伸,预先存在的拉伸线条逐渐向后期 X 方向旋转,纵横比减小。这些中间线状取向与早期或晚期变形没有运动学相关性。这个例子强调了温度、应变率和预先存在的拉伸线的方向在韧性剪切区拉伸线的外观和运动学解释中的重要性。直到后期变形的 X 方向累积的拉伸超过早期的有限拉伸,预先存在的拉伸线条逐渐向后期 X 方向旋转,纵横比减小。这些中间线状取向与早期或晚期变形没有运动学相关性。这个例子强调了温度、应变率和预先存在的拉伸线的方向在韧性剪切区拉伸线的外观和运动学解释中的重要性。直到后期变形的 X 方向累积的拉伸超过早期的有限拉伸,预先存在的拉伸线条逐渐向后期 X 方向旋转,纵横比减小。这些中间线状取向与早期或晚期变形没有运动学相关性。这个例子强调了温度、应变率和预先存在的拉伸线的方向在韧性剪切区拉伸线的外观和运动学解释中的重要性。
更新日期:2020-09-01
down
wechat
bug