Late Cretaceous evolution of the northern Sistan suture zone, eastern Iran: Implications of magnetic fabrics and microstructures in the Bibi Maryam granitoid

Journal of Earth system science

Mohammad Mahdi Khatib1¹  Zeinab Etemadkhah1¹  Mohammad Hossein Zarrinkoub1¹ 

[1] Department of Geology, Birjand University, Birjand, Iran.$$

关键词: Anisotropy of magnetic susceptibility;    transpression;    granitoid;    Sistan suture zone.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

Anisotropy of magnetic susceptibility (AMS) survey supported by field and microstructural studies have been applied on the Late Cretaceous Bibi Maryam granitoid (BMG) in the northern Sistan suture zone (SSZ), east of Iran. The BMG is composed of quartzdiorite-tonalite with late granodiorite dykes and stocks that are surrounded by steeply SW-dipping Neh shear zone (NSZ). The magmatic fabrics are characterized by transpressional environment dominated by steep dipping foliations (mean strike: N13°W) and sub-horizontal stretching lineations (mean trend: 167°). Based on microstructural studies, it is inferred that these fabrics are related to emplacement and cooling of the pluton and the internal fabrics revealed are evidence of a deformation continuum in the granitoid from magmatic to solid state. Deformation in the region continued even after the BMG had fully crystallized, which led to development of the NW–SE foliations and lineation trend that these fabrics are subparallel with the NSZ. The BMG has emplaced in a transpressional setting that was controlled by a NW–SE stretching direction and supported the model that has proposed the relationship between granitoid emplacement and oblique intra-oceanic subduction of the Neotethys during the Late Cretaceous already recognized in this part of the SSZ.

【 授权许可】

Unknown