-
Open Access Article
1 - Origin and significance of tourmaline-bearing rocks in Boroujerd region, Sanandaj-Sirjan zone, western Iran
Vahid Ahadnejad -
Open Access Article
2 - Preliminary Petrological Studies of Basement Rocks, Thar Coal Basin, Thar Parkar District, Sindh, Pakistan
Yasmin RizviThe basement rocks encountered in exploratory boreholes drilled for exploration and evaluation of coal deposits in Thar Parkar district, Sindh Pakistan have formed the basis for present studies. The basement complex was penetrated through eighteen boreholes at drill dep MoreThe basement rocks encountered in exploratory boreholes drilled for exploration and evaluation of coal deposits in Thar Parkar district, Sindh Pakistan have formed the basis for present studies. The basement complex was penetrated through eighteen boreholes at drill depth range from 112 to 279 meters. These rocks were identified in field as Pink and Grey Granites.. The basement rocks are of Igneous as well as metamorphic origin. The Igneous rocks identified petrographically are Alkali-feldspar Granite, Granodiorite, Rhyolite, Rhyodacite and Aplite while that of metamorphic origin is Plagioclase Hornblende Gneiss. These rocks are termed as Thar Granitoids. The chemical data plotted in various binary and ternary diagrams suggests that the Thar Granitoids are (1) in general peraluminous in nature (2) restricted to psuedoternary minimum at moderate water pressure. Manuscript profile -
Open Access Article
3 - CO2-H2O, Highly Saline and Carbonic Fluids from the Mesozoic Mashhad Granitoids, NE Iran
C. Srikantappa M. R. Kalantari M. N. MalathiThe Mesozoic Mashhad granitoid plutons have intruded into ophiolite complexes, meta-sediments and pyroclastics in the Binalood region, located SW of Mashad city in the NE part of Iran. Based on petrography and geochemistry, the Mashhad granitoids have been classified in MoreThe Mesozoic Mashhad granitoid plutons have intruded into ophiolite complexes, meta-sediments and pyroclastics in the Binalood region, located SW of Mashad city in the NE part of Iran. Based on petrography and geochemistry, the Mashhad granitoids have been classified into 1) grey granite, 2) pink granite, 3) muscovite granite, 4) granodiorite and 5) pegmatite and quartz veins. Granitoids show typical igneous micro-textures with the mineral assemblage of quartz, plagioclase, K-feldspar, biotite, muscovie, amphiboles, clinopyroxene and garnet. Based on two-feldspar thermometry and hornblende-plagioclase thermometry / barometry, igneous temperatures of 750 to 770oC and pressures of 4.6 to 5.5 kbars for the emplacement of granitoids have been estimated. The granitoids of Mashhad area have been classified as moderately peraluminous, S to I type granitoids of sub-alkaline to calcic type. Fluid inclusion study on Mashhad granitoids shows the presence of Isolated Fluid Inclusions (IFI) as well as Trail Bound Inclusions (TBI). Four types of fluid inclusions viz., Type I CO2-H2O inclusions, Type II Low salinity aqueous inclusions, Type III, high salinity inclusions and Type IV Carbonic inclusions have been recorded in Mashhad granitoids. Fluid inclusions occur as rounded, oval and negative crystal shape varying in size from 5 to 16 μm. CO2-H2O fluids are the most common fluids in Mashhad granitoids. CO2 in CO2-H2O inclusions varies from 20 to 80 percent. Minor bi-phase, low salinity aqueous inclusions occur. Presence of Type III, Halite bearing fluids are found mainly in quartz veins in granodiorite. Type IV, carbonic fluids occur along late fractures which cross-cut the early Type I, CO2-H2O fluids. CO2 in CO2-H2O inclusions shows Tm around -56.8 oC, indicating almost pure carbonic inclusions. TmClath vary from 4 to 8oC. Th of CO2 in liquid phase ranges from - 9 to 22o C with densities of 0.92 to 0.68 g/cc and the total homogenization of CO2-H2O ranges from 205 to 320oC, indicating XCO2 valuesof 0.75 to 0.20 mole fraction. The bi-phase fluid inclusions show low salinity values of 4 to 8 wt. % NaCl equivalent to 1.03 to 0.96 g/cc. Type-IV, late carbonic inclusions show Th ranging from 20 to 25°C with densities from 0.82 to 0.78 g/cc. Tye III, halite bearing fluids show temperatures of melting from 315 to 335oC with salinity values of 38 to 40 wt. % NaCl equivalent. The density data of fluids in Mashhad granitoids indicates entrapment temperatures of 590 to 650oC at pressures of 4.1 to 5.2 Kbar. This data nearly coincides with the mineral P-T estimates. There are strong evidences of “fluid-present” partial melting process during the formation of S-type and I-type granitoids in Mashhad area. The low density carbonic fluids are chronologicaly late fluids trapped in granitoids, formed due to the peferential leakage of water from the early CO2-H2O inclusions. Fluid leakage is related to ductile shear deformation along thrust zones in Mashhad granitoids. Manuscript profile -
Open Access Article
4 - Geochemical evolution and petrogenesis of the eocene Kashmar granitoid rocks, NE Iran: implications for fractional crystallization and crustal contamination processes
Rahim Dabiri Mohsen Akbari-Mogaddam Mitra Ghaffari -
Open Access Article
5 - the genesis and origion studies of haji abad granitoid pluton (south of boin zahra)
elham safarzade mansour وثوقی عابدینیHaji Abad granitoid pluton (~90Km²) is located in 135 Km southwest of Tehran , 7 Km south of Boin Zahracity (Fig.1).This pluton with approximate age 39.2(±3.2)Ma [4] emplaced in central of Uromieh – Dokhtar zonerocks .This pluton has a compositional ra MoreHaji Abad granitoid pluton (~90Km²) is located in 135 Km southwest of Tehran , 7 Km south of Boin Zahracity (Fig.1).This pluton with approximate age 39.2(±3.2)Ma [4] emplaced in central of Uromieh – Dokhtar zonerocks .This pluton has a compositional rang of granitoid rocks include syenogranite , monzogranite , granodioriteand granophyr . Under study pluton in view of magmatic series is calk-alkaline , medium to high K and in viewof alumina saturation index is meta-alumine nature .Field , geology , petrography and geochemical study indicatethat these granitoids are High temperature magnetite I-type or Cordiller I- type granitoids . Manuscript profile -
Open Access Article
6 - Ahmadnejad
Esmaiel DarvishiThe Dehno granite massive is located in the East Dehno village and southern Khomein city and within themetamorphic Sanandaj–sirjan Zone. The composition of these rocks include: granodiorite, quartzdiorite(tonalite), monzogranite and leucogranite. Quartz, alkali fe MoreThe Dehno granite massive is located in the East Dehno village and southern Khomein city and within themetamorphic Sanandaj–sirjan Zone. The composition of these rocks include: granodiorite, quartzdiorite(tonalite), monzogranite and leucogranite. Quartz, alkali feldspar, plagioclase, biotite, andalusite, hornblendemuscovite, tourmaline, zircon and apatite are examples of the existing major and minor minerals in theseintrusive rocks. This body is host the tourmaline bearing silica veins and dykes and mafic enclave microgranolaraplitic (several) and doleritic (seldom). Mineralogy and geochemical studies this rocks indicated mantlePeraluminium and calc alkaline and mixing origin(melting of the oceanic crust of the Neo-Tethyan belowCentral Iranian Microplate) and anatexi melting (the melting of continental crust sediments) and rocksenrichment LILE elements such as granite(Rb, K, Cs) and the concentration of depleted elements, particularlyHFSE Ti, Nb and P is consistent with the pattern of granites associated with the subduction setting and from thetectonic environment aspect, they are considered as the volcanic arc granitoids (VAG). Manuscript profile -
Open Access Article
7 - Exploration and introduction of decorative stones in the Saghand-Chadormalu province, centeral Iran and their comparision with the mashhad granitoid
Habibolah Torshizian Habib Mollai Mohsen Allameh
Sanad
Sanad is a platform for managing Azad University publications
Links
Related Centers
Technical Support
Official pages
The rights to this website are owned by the Raimag Press Management System.
Copyright © 2021-2024