Magmatic and metamorphic history of the Deh-Salm metamorphic Complex, Eastern Lut block, (Eastern Iran), from U–Pb geochronology

Abstract

The Deh-Salm metamorphic Complex (DMC) of the Lut block in East Iran consists of metapelites, amphibolites, marbles, and metasandstones intruded by granite and pegmatites. U-Pb dating of zircon, monazite, xenotime, and titanite by ID-TIMS show that the granitic rocks were emplaced at 166-163 Ma, confirming that the high temperature metamorphism was synchronous with the intrusive activity, and that the region cooled rapidly thereafter. Late-to post-magmatic hydrothermal activity was probably responsible for the late crystallization, at 159.5 Ma, of zircon and titanite in an amphibolite and of monazite in granite. Xenocrystic zircons yield indications for a Carboniferous component in the source, together with a variety of Precambrian ages, which indicate a provenance of the sedimentary protolith from mature continental crust. The timing and rapidity of the events are consistent with evolution of the DMC in a back-arc environment during the Jurassic subduction of the Neotethys Ocean.

U–Pb dating and emplacement history of granitoid plutons in the northern Sanandaj–Sirjan Zone, Iran

“…In the southern SSZ a gabbroanorthosite complex was emplaced during the same event (Fazlnia et al, 2007). Mid-Jurassic magmatism was also responsible for the genesis of granites intruding into and metamorphosing the Deh Salm Metamorphic Complex of the Lut Block of East Iran (Mahmoudi et al, 2010). This synchronous activity all along the SSZ and surrounding regions can be related to initiation of subduction of the Neotethys oceanic crust below the Iranian continental crust (Bagheri and Stampfli, 2008).…”

Origin of the Kaviro lead deposit in the Neyganan area, Lut Block, Eastern Iran: Constraints from geology, fluid inclusions, and isotope geochemistry

“…Outcrops of igneous rocks enclose an area of approximately 300 km × 400 km, which is a minimum calculation because their exposure might reach far into western Afghanistan (Richards et al, 2012). Quaternary desert sands spread over a vast area of the Lut Block, spatially to the south in the Dasht-e-Lut desert, which shows the Lut Depression (Mahmoudi et al, 2010). The magmatic activity in the Lut Block was established in the middle Jurassic from 165-162 Ma and reached its maximum in the Tertiary (Karimpour et al, 2011).…”

Cimmerian metamorphism and post Mid-Cimmerian exhumation in Central Iran: Insights from in-situ Rb/Sr and U/Pb dating

“…During the Middle Jurassic, before the anticlockwise rotation of the CEIM (Mattei et al, 2015), the Lut block was located, like the Sanandaj-Sirjan Cimmerian block, in the upper plate magmatic arc setting of the Neotethyan subduction zone (Figs. 3, 14;Esmaeily et al 2005;Bröcker et al 2014;Mahmoudi et al 2010). This period between 170 and 160 Ma therefore corresponds to an important geodynamic evolution, from Paleotethys closure and Eo-Cimmerian orogeny to a prevalence of Neotethys subduction dynamics with back-arc basin formation from the Middle Jurassic onwards (Agard et al, 2011;Moghadam and Stern, 2015).…”