Petrology, geochemistry, source and tectonic setting of Malek Chah Ruii granitoid (East of Lut Block)

Abstract

The Malek Chah Rouii granitoid pluton is exposed within the Deh-Salm metamorphic complex in the eastern margin of the Lut zone. The studied granitoid with peraluminous and calc-alkaline nature is composed of tonalite, granodiorite, and granite (monzo- and syenogranite). The predominant minerals are quartz, plagioclase, microcline, orthoclase, biotite, and muscovite with granular, myrmekite to poikiliitic textures. The similar trends of trace and REE on geochemical diagrams normalized to primary mantle and chondrite could be indicative of the common origin of the rocks under study. Furthermore, they are enriched in Rb, Th, U, K, Pb, Nd, La, Sm, Hf, Ce, and Pr and depleted in Nb, Sr, P, Ti, and Zr. These characteristics are the common features of the magmas formed in active continental subduction zones affected by continental crust. This pluton is a post-collision type originated in a normal to mature continental arc from a protolith with a poor clay metagreywacke composition involving biotite dehydration. The Al2O3+FeOt+MgO+TiO2vs. Al2O3/(FeOt+MgO+TiO2), SiO2 vs. p 2O5, and. Zr as well as the Qtz-Ab-Or ternary diagram show that the Malek Chah Rouii granitoid formed at ≥5 kbarwater vapor pressure and an average temperature of 775℃. Key words:S-type granitoid, post-collision, source, Nehbandan, Lut Block

Keywords

• the malek chah rouii granitoid pluton is exposed within the deh-salm metamorphic complex in the eastern margin of the lut zone. the studied granitoid with peraluminous and calc-alkaline nature is composed of tonalite
• granodiorite
• and granite (monzo- and syenogranite). the predominant minerals are quartz
• plagioclase
• microcline
• orthoclase
• biotite
• and muscovite with granular
• myrmekite to poikiliitic textures. the similar trends of trace and ree on geochemical diagrams normalized to primary mantle and chondrite could be indicative of the common origin of the rocks under study. furthermore
• they are enriched in rb
• th
• u
• k
• pb
• nd
• la
• sm
• hf
• ce
• and pr and depleted in nb
• sr
• p
• ti
• and zr. these characteristics are the common features of the magmas formed in active continental subduction zones affected by continental crust. this pluton is a post-collision type originated in a normal to mature continental arc from a protolith wi
• sio2 vs. p2o5
• and. zr as well as the qtz-ab-or ternary diagram show that the malek chah rouii granitoid formed at ≥5 kbar water vapor pressure and an average temperature of 775℃. s-type granitoid
• post-collision
• source
• nehbandan
• lut block