Abstract We present the structural history of a suite of high-grade rocks of the Phulbani area of the Eastern Ghats Belt, India, with published metamorphic and geochronological data. Structural data suggest multiple generations of fabric (S1-S5) development during a punctuated deformational history (D1-D5). The S1 fabric is present only in grain-scale and developed during the prograde metamorphic stage (M1). The regionally recognizable composite S2/S3 gneissic fabric developed in the realm of ultra-high temperature metamorphism (D2/D3, M2) during ca. 987–970 Ma as a result of the contraction and closure of the continental back-arc basin. The D4 deformation folded the earlier formed composite S2/S3 gneissic fabric and developed a shear-related mylonitic foliation (S4), possibly after ca. 970 Ma. Deformation in the Phulbani area culminated through the formation of the S5 mylonitic fabric (D5, M3) along the Ranipathar Shear Zone, possibly at ca. 500 Ma, which exposed the anomalously hot deep continental crustal rocks to shallower crustal level. Development of the Ranipathar Shear Zone is interpreted to be kinematically linked with several other such crustal-scale shear zones in the area which together played a pivotal role in the final tectonic evolution of the northern Eastern Ghats Belt.

中文翻译：

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深部大陆地壳的多相变形和超高温变质作用：对印度东高止山脉北部构造演化的启示

摘要 我们介绍了印度东高止山脉 Phulbani 地区的一套高品位岩石的构造历史，以及已发表的变质和地质年代学数据。结构数据表明，在间断变形历史 (D1-D5) 期间，织物 (S1-S5) 发生了多代发展。S1 织物仅以颗粒尺度存在，并在顺行变质阶段 (M1) 中发育。区域可识别的复合 S2/S3 片麻岩织物在大约 10 年的超高温变质（D2/D3，M2）领域开发。由于大陆弧后盆地的收缩和闭合，987-970 Ma。D4 变形折叠了较早形成的复合 S2/S3 片麻岩织物，并形成了与剪切相关的糜棱片理 (S4)，可能在大约 10 年之后。970 马。Phulbani 地区的变形通过沿着 Ranipathar 剪切带形成 S5 糜棱结构（D5，M3）而达到顶峰，可能在大约 500 Ma，将异常热的深部大陆地壳岩石暴露到较浅的地壳层。Ranipathar 剪切带的发展被解释为与该地区其他几个这样的地壳尺度剪切带在运动学上联系在一起，这些剪切带在东高止山脉北部的最终构造演化中发挥了关键作用。