Seismic evidence of mylonite reflectivity and deep structure in the Kettle dome metamorphic core complex, Washington
Seismic evidence of mylonite reflectivity and deep structure in the Kettle dome metamorphic core complex, Washington
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华盛顿州 Kettle Dome 变质核杂岩中糜棱岩反射率和深层结构的地震证据
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
M. Humphreys
中科院分区：
文献类型：
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作者：
C. Hurich;S. Smithson;D. Fountain;M. Humphreys
首次直接测试糜棱岩的地震反射率是由华盛顿东北部Kettle穹变质核杂岩中出露的糜棱岩带的地震反射剖面提供的。糜棱岩带发育于中地壳水平，在隆升过程中经历了最小程度的退积和碎裂作用。暴露的糜棱岩带向下倾斜投影到地震剖面表明，组成分层糜棱岩带是反射性的，可追溯到至少5公里的深度作为一个复杂的多循环反射区。地震数据还表明，凯特尔穹丘下方的地壳具有丰富的、强反射的、中等倾斜的地层，深度至少为18公里。这些层可以解释为挤压或伸展造山事件或两者的组合。变质核杂岩的结构和成因模型必须考虑到这些数据。
The first direct test of the seismic reflectivity of mylonites is provided by a seismic reflection profile over a mylonite zone exposed in the Kettle dome metamorphic core complex, northeastern Washington. The mylonite zone developed at mid-crustal levels and has undergone a minimum of retrogression and cataclasis during uplift. Downdip projection of the exposed mylonite zone into the seismic profile indicates that the compositionally layered mylonite zone is reflective and traceable to at least 5-km depth as a complex zone of multicyclic reflections. The seismic data also show that the crust beneath the Kettle dome is characterized by abundant, strongly reflective, moderately dipping layers down to at least 18 km. These layers can be interpreted in terms of compressional or extensional orogenic events or a combination of both. Models for the structure and genesis of metamorphic core complexes must take these data into account.