List of articles (by subject) Petrology
-
Open Access Article
1 - Study of A-type granite from the South of Lake Urmia, Sanandaj-Sirjan Zone: implications for the Neotethys opening in Iran
Nasser Ashrafi Mehrdad Pourmohsen Morovvat FaridazadThe magmatic evidence of the Neotethys opening in Iran, such as the Late Paleozoic A-type granitoids, was mainly discovered along the Sanandaj-Sirjan Zone and parallel to the Neotethys suture. Therefore, they may provide important clues about the geodynamic evolution of MoreThe magmatic evidence of the Neotethys opening in Iran, such as the Late Paleozoic A-type granitoids, was mainly discovered along the Sanandaj-Sirjan Zone and parallel to the Neotethys suture. Therefore, they may provide important clues about the geodynamic evolution of the Sanandaj-Sirjan Zone. The South of Lake Urmia (SLU) granite is situated near the Khalifan A-type pluton (315±2 Ma) with a cover of the Permian sediments. The rock-forming minerals of the SLU granite consist of quartz, alkali-feldspars (K-rich and microperthitic), sodic plagioclases, biotite (Fe-rich), zircon, apatite, and Fe-Ti oxides. The chemical composition of the SLU granite is characterized by high FeOt/MgO and (Na2O+K2O)/CaO ratios, which are typical features of A-type granites. Furthermore, the studied rocks exhibit the chemical characters of the A1 subgroup of A-type granites with peraluminous and K2O-rich affinities. On the multi-element spider plot, the SLU granite shows distinct negative Ba, Sr, P, and Ti anomalies and positive Pb anomalies. Moreover, the Chondrite-normalized rare earth elements (REE) patterns display slope downwards from LREE to HREE, with flattening at the HREE end and distinct negative Eu anomalies. The ratios of trace elements provide evidence for the contribution of the OIB-like mafic melts with crustal interactions to generate the granitic magmas of the SLU pluton. The compositional and stratigraphic features of the SLU granite are also consistent with an extensional setting during the Late Paleozoic in Iran. Therefore, the genesis of the SLU granite can be attributed to the syn-rift magmatism of the Cimmerian terranes. A comprehensive review of the Late Paleozoic rocks occurrence shows that they mainly are emerged in the northeast margin of the Sanandaj-Sirjan Zone and around the structural depressions such as Lake Urmia (so-called Tertiary fore-arc or Mesozoic back-arc). Manuscript profile -
Open Access Article
2 - The petrology and geochemistry of Sorkheh-Dizaj intrusive rocks in northern Zanjan and its effects on recovery of LREE from tailingby digestion-water leaching processes, Iran
Ahmad Adib Esmaeil RahimiMagnetite-apatite mineralization in Tarom Mountains at the western part of Alborz-Azerbaijan belt originated from quartz monzonite magma and belongs to high K calc-alkaline, showing a post-collision tectonic environment. The negative trend from LREEs to HREEs is consist MoreMagnetite-apatite mineralization in Tarom Mountains at the western part of Alborz-Azerbaijan belt originated from quartz monzonite magma and belongs to high K calc-alkaline, showing a post-collision tectonic environment. The negative trend from LREEs to HREEs is consistent with the spider pattern of the subduction areas. In this article, the recovery of the rare-earth elements (REEs) from apatite flotation concentrate by acid leaching and digestion-water leaching were studied. The total amount of LREEs in the tailings sample is between 1500 - 2600 ppm. The most frequent elements are Ce, La, Nd, and Y. Among them Ce is the most abundant and La is the least.. The maximum LREEs recovery with the sulfuric acid leaching was62% with experimental parameters of 12 M acid concentration, 4 h leaching time, 25℃ heat, and a liquid to solid ratio (L/S) of 1:5. under optimal parameters of (220℃), (3 h), and L/S (1:2), the digesting with sulfuric acid resulted to the recovery of La, Ce, Nd, and Y with 93.92%, 92.22%, 92.04%, and 91.00%, respectively. similarity, the best conditions at water leaching process, are the leaching time of 5 h, at 80℃, and L/S of 1:10 for La, Ce, Nd, and Y recovery are respectively 89.50%, 88.45%, 92.20%, and 94.0%. Manuscript profile -
Open Access Article
3 - Geochemistry and tectonomagmatic environment of Eocene volcanic rocks in the Southeastern region of Abhar, NW Iran
Masoud Nazari Mohammad Ali Arian Ali Solgi Reza Zareisahamieh Abdollah YazdiEocene volcanic are exposed in southeast of Zanjan in the Tarom magmatic zone that located in the Central Iran structural zone. The Abhar Eosen pyroclastic with andesite, trachy-andesite, dacite and rhyolite along with tuff compositions is located 120 km southeast of Za MoreEocene volcanic are exposed in southeast of Zanjan in the Tarom magmatic zone that located in the Central Iran structural zone. The Abhar Eosen pyroclastic with andesite, trachy-andesite, dacite and rhyolite along with tuff compositions is located 120 km southeast of Zanjan. Mineralogically point of view, the studied volcanic rocks have low quartz, negligible alkaline feldspar, abundant plagioclase, and pyroxene contents. Textureally, Porphyritic, microlithic porphyritic, glomeroporphyritic, and poikilitic are predominant in these rocks. All of the studied samples display REE patterns characterized by LREE-enriched (Rb and Ba) and HREE-depleted segments typical of arc lavas which is one of the characteristics of subduction zone. The geochemical characteristics of the studied samples indicated that fractional crystallization is the primary cause of the diversity and differentiation of these rocks compared to crustal contamination. The rocks of the study area are composed of a similar origin to the OIB (mantle components) and partial melting of subcontinental lithospheric mantles. Of course, this mantle source has been modified by recycled sediments and melt released from the edge of the subducting oceanic crust. Manuscript profile