Deformational History of the Granjeno Schist, Ciudad Victoria, Mexico: Constraints on the Closure of the Rheic Ocean?
Deformational History of the Granjeno Schist, Ciudad Victoria, Mexico: Constraints on the Closure of the Rheic Ocean?
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墨西哥维多利亚城格兰杰诺片岩的变形历史：对瑞克洋闭合的限制？
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
J. W. Lee
中科院分区：
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作者：
D. Dowe;R. Nance;J. Keppie;K. L. Cameron;A. Ortega;F. Ortega;J. W. Lee;J. W. Lee
Granjeno片岩出露于墨西哥东北部Laramide褶皱冲断带的NNW向前缘背斜的核部，由古生代变质沉积岩和变质火山岩以及蛇纹化镁铁质-超镁铁质单元的多变形组合组成。最早的变形（D1）早于351 ± 54 Ma的浅色花岗岩侵位，可能记录了该大洋单元的仰冲。随后的变形（D2 a-D2c）记录了在温度降低的条件下，通过北北西向右旋剪切作用，Granjeno片岩与101 Ga Novillo片麻岩的构造并置。313 ± 13 Ma和300 ± 4 Ma的冷却年龄被认为是右旋运动的开始，并持续到二叠纪。这些事件与晚古生代莱茵洋的闭合有关。
Exposed in the core of a NNW-trending frontal anticline of the Laramide fold-thrust belt of northeastern Mexico, the Granjeno Schist comprises a polydeformed assemblage of Paleozoic metasedimentary and metavolcaniclastic rocks and serpentinized mafic-ultramafic units. The earliest deformation (D1) predates emplacement of a leucogranite at 351 ± 54 Ma and may record obduction of this oceanic unit. Subsequent deformations (D2a-D2c) record tectonic juxtapositioning of the Granjeno Schist against the ∼1 Ga Novillo Gneiss by NNW-directed dextral shear under conditions of decreasing temperature. Cooling ages of 313 ± 13 Ma and 300 ± 4 Ma are considered to date the onset of dextral motion, which continued into the Permian. These events are linked to the Late Paleozoic closing of the Rheic Ocean.