Thermal model for the Zanskar Himalaya
1989; Wiley; Volume: 7; Issue: 1 Linguagem: Inglês
10.1111/j.1525-1314.1989.tb00579.x
ISSN1525-1314
Autores Tópico(s)earthquake and tectonic studies
ResumoABSTRACT Crustal thickening along the northern margin of the Indian plate, following the 50 Ma collision along the Indus Suture Zone in Ladakh, caused widespread high‐temperature, medium‐pressure Barrovian facies series metamorphism and anatexis. In the Zanskar Himalaya metamorphic isograds are inverted and structurally telescoped along the Main Central Thrust (MCT) Zone at the base of the High Himalayan slab. Along the Zanskar valley at the top of the slab, isograds are the right way‐up and are also telescoped along northeast‐dipping normal faults of the Zanskar Shear Zone (ZSZ), which are related to culmination collapse behind the Miocene Himalayan thrust front. Between the MCT and the ZSZ a metamorphic‐anatectic core within sillimanite grade rocks contains abundant leucogranite‐granite crustal melts of probable Himalayan age. A thermal model based on a crustal‐scale cross‐section across the Zanskar Himalaya suggests that M 1 isograds, developed during early Himalayan Barrovian metamorphism, were overprinted during high‐grade MCT‐related anatexis and folded around a large‐scale recumbent fold developed in the hanging wall of the MCT.
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