Poly-deformation and fabrics in the Shurow metamorphic complex, west Sirjan
Subject Areas :
Keywords: polyphase deformation Sirjan mylonitic granite Shurow metamorphic complex,
Abstract :
Three deformation and two metamorphic phases are examined in the Shurow metamorphic complex located in SE of the Sanandaj-Sirjan zone. All deformation and metamorphic phases are produced during post-middle Jurassic and are studied in three areas of Chah Gaz, Chah Anjir and Dochah Zahra based on trends of the second generation map-scale folds. The first generation of folds are NW and SE shallowly to moderately plunging isoclinal folds associated with continuous axial plane foliation, shallowly-moderately dipping to NE. The second generation of folds are NE and SW shallowly plunging open to close folds associated with axial plane crenulation foliation, steeply dipping to N and S. A NE -SW trending vertical compositional foliation is also developed in Cah Gaz metamorphic rocks. Local dextral strike-slip ductile shear zones are generated sub-parallel to the compositional foliation. Muscovite is crystalized along the axial plane foliations of the first and second generation of folds indicating low T & P green-schist facies condition. The third generation of folds are upright NW shallowly (Chah Anjir area) moderately (Chah Gaz area) plunging folds. The first deformation phase in Dochah Zahra area is identified by E -W oriented ductile shear zones, including syn-tectonic granite intrusion that are folded along the stretching lineation by NW-SE shal plunging folds containing moderately to steeply dipping axial plane foliation.