Petrology
zahra badrzadeh
Abstract
Abstract The studied Chaltian granitoid is located in the endpoint of the southern Sanandaj–Sirjan Zone. This pluton has Low-Al trondhjemitic composition with tholeiitic to transitional nature. The intrusion has been intruded in the early Mesozoic volcanic and sedimentary rocks. According to U-Pb ...
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Abstract The studied Chaltian granitoid is located in the endpoint of the southern Sanandaj–Sirjan Zone. This pluton has Low-Al trondhjemitic composition with tholeiitic to transitional nature. The intrusion has been intruded in the early Mesozoic volcanic and sedimentary rocks. According to U-Pb SHRIMP age dating of zircon grains, this pluton was intruded at the 187.5 ±3.2Ma ago. Studied pluton has low Al2O3, Sr/Y, (La/Yb)N ratio and less fractionated REE pattern. In the primitive mantle normalized spider diagrams, studied samples show enrichment of LIL elements such as K, Rb, Ba and Th relative to HFS elements and has negative anomaly in Ta, Nb and Ti elements, which are considered characteristic of magmas generated in subduction related settings. In terms of their origin, based on geological and geochemical characteristics, trondhjemitic melt has been generated by low pressure dehydration melting of amphibolitic source in an continental extensional tectonic setting related to subduction environment.
M.R Sheikholeslami
Abstract
Different characteristics of the rock units and their stratigraphic relationships, as well as magmatic and metamorphic activities in the southern part of the Sanandaj-Sirjan Zone resulted in identification of different tectono-stratigraphic units based on their tectonic environments reflecting the opening ...
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Different characteristics of the rock units and their stratigraphic relationships, as well as magmatic and metamorphic activities in the southern part of the Sanandaj-Sirjan Zone resulted in identification of different tectono-stratigraphic units based on their tectonic environments reflecting the opening and closure of the Neotethys Ocean in southern Iran. The major tectono-stratigraphic units identified in this study are as follows: sediments deposited in the aulacogen setting in southern part of the Central Iranian platform of Paleozoic to Middle Triassic age; Triassic volcanic rocks and turbiditic sediments; low-grade flysch-type sediments of Jurassic-Early Cretaceous age deposited in a forearc basin; Lower Cretaceous carbonate platform sediments; suture zone-related rocks containing ophiolite, radilolarite and glaucophane schists; Tertiary flysch-type sediments containing exotic blocks of Lower Cretaceous carbonate, ophiolite and of the Zagros Formations formed over the edge of High Zagros zone; retro-arc foreland sediments of Central Iran which unconformably overlie the deformed rocks of northeastern part of the area; and finally post-orogenic molasse-type sediments resulted from post uplift erosion of the Zagros orogeny, deposited in the internal and marginal parts of the southern Sanandaj-Sirjan zone.
