Petrography and geochemistry of the Padagi dikes (South of Zahedan, Sistan Suture Zone)

Abstract

Padagi area is located in southern part of Sistan Suture Zone. In this area, the Eocene flysch-like rocks were intruded by Oligocene-Miocene igneous rocks as batholith, dacitic stock and dacitic to andesitic dike. The flysch is predominantly composed of altered phyllite, shale, sandstone and siltstone. The batholith is mainly an I-type granular granodiorite. The stock is associated with granodiorite porphyry, quartz-diorite porphyry, quartz-monzonite porphyry and andesite. The dikes, trending NE, are last magmatic phase, and porphyry texture. The igneous rocks in Padagi are mainly high K calc-alkaline and metaluminous belonging to continental margin post-collision magmatic arcs. The minor and rare earth elements, normalized to the primitive and the chondrite mantle, respectively, show that LREE and LILE are enriched relative to HREE and HFSE, respectively, a remarkable feature of igneous rocks related to volcanic arc. According to geochemical studies, for the Padagi samples could assume a garnet-bearing enriched asthenospheric and lithospheric sources with a partial melting of less than 5 % as parent magma generated in 80 to 100 km depth.

Keywords

• zahedan batholith
• intermediate dikes
• high-k calc-alkaline
• padagi
• sistan suture zone