University of IsfahanPetrological Journal2228-521031020121121The origin of ore-forming fluids in the Mahour polymetal ore deposit, using electron microprobe data and sulfur isotopes (East of Lut block, Central Iran)The origin of ore-forming fluids in the Mahour polymetal ore deposit, using electron microprobe data and sulfur isotopes (East of Lut block, Central Iran)11216098FARezvanMirzaei RayeniAliAhmadiدانشکده علوم، گروه زمین شناسیHassanMirnejadJournal Article20160614The Mahour polymetal deposit, located east of the Lut block, is a three-km-long and 0.5-2m wide vein formed in hypabyssal acid rocks. Downward, three leached zones (malachite, azurite, hematite, goethite and atacamite), supergene (bornite, covellite, chalcocite, anglesite, greenockite and hawleyite), and hypogene (magnetite, chalcopyrite, pyrite, galena and sphalerite) are observed in the deposit. The results of electron microprobe analyses show the presence of varying amounts of Ag, As, Sb, In, Cd, Zn, Fe and Cu, in the sulfide minerals of Mahour deposit. Three rare mineral phases, namely atacamite, greenockite and hawleyite in the leached and supergene zones, were identified by the electron microprobe analyses. The types of alteration present in the deposit are silicic, sericitic, propylitic, argillic, and potassic. The ï¤34SCDT values for eight sulfide samples (pyrite, chalcopyrite, galena, sphalerite and bornite) in Mahour deposit vary between 0.2 to 4.07%, with a mean value of 2.96%. Inferred temperature from thermometric calculations, based on the sulfur isotope compositions of sulfide pairs in equilibrium, indicate temperatures of 215-380 ºC. Therefore, it is concluded that sulfur needed for the generation of sulfide minerals in the Mahour polymetal deposit was supplied by either ore-forming fluids or igneous rocks in the region.The Mahour polymetal deposit, located east of the Lut block, is a three-km-long and 0.5-2m wide vein formed in hypabyssal acid rocks. Downward, three leached zones (malachite, azurite, hematite, goethite and atacamite), supergene (bornite, covellite, chalcocite, anglesite, greenockite and hawleyite), and hypogene (magnetite, chalcopyrite, pyrite, galena and sphalerite) are observed in the deposit. The results of electron microprobe analyses show the presence of varying amounts of Ag, As, Sb, In, Cd, Zn, Fe and Cu, in the sulfide minerals of Mahour deposit. Three rare mineral phases, namely atacamite, greenockite and hawleyite in the leached and supergene zones, were identified by the electron microprobe analyses. The types of alteration present in the deposit are silicic, sericitic, propylitic, argillic, and potassic. The ï¤34SCDT values for eight sulfide samples (pyrite, chalcopyrite, galena, sphalerite and bornite) in Mahour deposit vary between 0.2 to 4.07%, with a mean value of 2.96%. Inferred temperature from thermometric calculations, based on the sulfur isotope compositions of sulfide pairs in equilibrium, indicate temperatures of 215-380 ºC. Therefore, it is concluded that sulfur needed for the generation of sulfide minerals in the Mahour polymetal deposit was supplied by either ore-forming fluids or igneous rocks in the region.https://ijp.ui.ac.ir/article_16098_cb08fcc8161b2f2a818379fb7a1e1c29.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Petrography and tectonic setting investigation of Tertiary igneous rocks in the Nodoushan area (SW of Sadough, Yazd province)Petrography and tectonic setting investigation of Tertiary igneous rocks in the Nodoushan area (SW of Sadough, Yazd province)132616101FABijanEtemadiBatoulTaghipourAbdolhadiGhobadiAminEslamiMostafaSalimi DaraniJournal Article20160614The Tertiary igneous rocks of Nodoushan area cropped out at about 130 km southwest of Yazd city in the Uromieh-Dokhtar Volcano-Plutonic belt. Based on the mineralogical and geochemical studies, these volcanic rocks are composed of dacite, andesite, olivine basalt, and also pyroclastic (crystalline tuff), and micro-granodioritic intrusive rocks. Based on Y-Nb versus Y-Zr and Zr/Al2O3 versus TiO2/Al2O3 tectonomagmatic diagrams, these rocks show some indications of magmatic arc tectonic setting. As observed from the Ce/P2O5 vs. Zr/TiO2 diagram which discriminates the magmatic arcs of active continental margin from post-collision magmatic arcs, the studied rocks belong to the post-collision arcs (PAP). In the spider diagram normalized to MORB, HFS elements shows depletion, characteristic of magmatism at the volcanic arc setting. The K, Rb and Th enrichment as well as the negative anomaly of Ti, Ta, Nb and P indicate that the rocks studied formed in subduction zone.The Tertiary igneous rocks of Nodoushan area cropped out at about 130 km southwest of Yazd city in the Uromieh-Dokhtar Volcano-Plutonic belt. Based on the mineralogical and geochemical studies, these volcanic rocks are composed of dacite, andesite, olivine basalt, and also pyroclastic (crystalline tuff), and micro-granodioritic intrusive rocks. Based on Y-Nb versus Y-Zr and Zr/Al2O3 versus TiO2/Al2O3 tectonomagmatic diagrams, these rocks show some indications of magmatic arc tectonic setting. As observed from the Ce/P2O5 vs. Zr/TiO2 diagram which discriminates the magmatic arcs of active continental margin from post-collision magmatic arcs, the studied rocks belong to the post-collision arcs (PAP). In the spider diagram normalized to MORB, HFS elements shows depletion, characteristic of magmatism at the volcanic arc setting. The K, Rb and Th enrichment as well as the negative anomaly of Ti, Ta, Nb and P indicate that the rocks studied formed in subduction zone.https://ijp.ui.ac.ir/article_16101_50957096ab43cc48acebfa3fc9cd7fca.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Mineralogical study of metabasites in Me'raji and Chah Palang Mountains (South of Chupanan, NE Isfahan province)Mineralogical study of metabasites in Me'raji and Chah Palang Mountains (South of Chupanan, NE Isfahan province)274416102FAFereshtehBayatGhodratTorabiگروه زمین شناسی دانشگاه اصفهانJuergenKoepkeJournal Article20160614The metabasites of Me'raji and Chah Palang Mountains located south of Chupanan (Central Iran) and covered by the Paleozoic metamorphic complexes. These metabasites are composed of closely associated metabasalts, metagabbros, and metadiabases. The metabasites of Me'raji and Chah Palang Mountains are metamorphosed in greenschist and amphibolite facies, respectively. Following the peak metamorphism, these rocks suffered a retrograde metamorphism of greenschist facies. Field observations, petrographic and mineralogical features reveal significant differences between both metabasite occurrences. Rock forming minerals are plagioclase, clinopyroxene and amphibole. Accessory minerals are biotite, illmenite, titanomagnetite and titanite. Chlorite, epidote, pumpellyite, leucoxene and calcite are secondary minerals. The Chah Palang metabasites have higher K2O and TiO2 contents in comparison with that of the Me'raji metabasites. The Na2O content of the Me'raji metabasites is 6.86-8.40 (wt%), implying spilitization of pillow lavas by sub-sea floor metamorphism. The hornblende-plagioclase thermometry and Al in amphibole barometry reveal different conditions for the metamorphism. The equilibrium temperature for the Chah Palang area was estimated 562-752 ºC at pressure of 7-8 kbar, while in the Me'raji area 426-520 ºC at pressure of 5-6 kbar were obtained.The metabasites of Me'raji and Chah Palang Mountains located south of Chupanan (Central Iran) and covered by the Paleozoic metamorphic complexes. These metabasites are composed of closely associated metabasalts, metagabbros, and metadiabases. The metabasites of Me'raji and Chah Palang Mountains are metamorphosed in greenschist and amphibolite facies, respectively. Following the peak metamorphism, these rocks suffered a retrograde metamorphism of greenschist facies. Field observations, petrographic and mineralogical features reveal significant differences between both metabasite occurrences. Rock forming minerals are plagioclase, clinopyroxene and amphibole. Accessory minerals are biotite, illmenite, titanomagnetite and titanite. Chlorite, epidote, pumpellyite, leucoxene and calcite are secondary minerals. The Chah Palang metabasites have higher K2O and TiO2 contents in comparison with that of the Me'raji metabasites. The Na2O content of the Me'raji metabasites is 6.86-8.40 (wt%), implying spilitization of pillow lavas by sub-sea floor metamorphism. The hornblende-plagioclase thermometry and Al in amphibole barometry reveal different conditions for the metamorphism. The equilibrium temperature for the Chah Palang area was estimated 562-752 ºC at pressure of 7-8 kbar, while in the Me'raji area 426-520 ºC at pressure of 5-6 kbar were obtained.https://ijp.ui.ac.ir/article_16102_e89669e48a4661d1c94fccc9496d37cf.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Geochemistry of alteration zones and shear zone with an emphasis on the behavior of rare earth elements (REE) in the Qolqoleh Gold deposit, KurdistanGeochemistry of alteration zones and shear zone with an emphasis on the behavior of rare earth elements (REE) in the Qolqoleh Gold deposit, Kurdistan456416097FABatoulTaghipourشیراز- چهارراه ادبیات-دانشکده علوم شماره1-بخش علوم زمین تقی پورFarhadAhmadnejadJournal Article20160614The Qolqoleh gold deposit located 50 km northwestof the Sanandaj-Sirjan metamorphic-magmatic zone. The area was affected by NE-SW trending shear zone. On the basis of the field prospecting, granitic intrusive rocks, meta-limestone, chlorite- sericite schist and metavolcanic units are altered. The intrusive body ranges in composition from granitic through granodiorite to diorite. The petrographic studies display that the altered intrusive rocks composed of quartz, K-feldspar, muscovite, biotite, sericite, microcline, chlorite, iron oxide and calcite. Propylitic, phyllic, carbonatization and silicic zones are the main types of alteration in the area. From the viewpoint of tectonic environment, the intrusive bodies are emplaced in a post- collision volcanic arc setting. The rare earth elements pattern in the metavolcanic of the shear zone indicates that REE are enriches in the shear zone compared to the hanging wall (chlorite-sericite schist) and foot wall (metalimestone) units. It seems that, LREE enrichment can be related to the circulation of SO4-2, CO2 -bearing fluids as well as regional metamorphic in the Qolqoleh shear zone. The presence of positive and negative Eu anomaly in the metavolcanic rocks is due to the low and advance alteration respectively. The negative anomaly is related to plagioclase alteration in these rocks. The lack of Eu anomaly in the hanging wall and foot wall indicate that these rocks are unaltered.The Qolqoleh gold deposit located 50 km northwestof the Sanandaj-Sirjan metamorphic-magmatic zone. The area was affected by NE-SW trending shear zone. On the basis of the field prospecting, granitic intrusive rocks, meta-limestone, chlorite- sericite schist and metavolcanic units are altered. The intrusive body ranges in composition from granitic through granodiorite to diorite. The petrographic studies display that the altered intrusive rocks composed of quartz, K-feldspar, muscovite, biotite, sericite, microcline, chlorite, iron oxide and calcite. Propylitic, phyllic, carbonatization and silicic zones are the main types of alteration in the area. From the viewpoint of tectonic environment, the intrusive bodies are emplaced in a post- collision volcanic arc setting. The rare earth elements pattern in the metavolcanic of the shear zone indicates that REE are enriches in the shear zone compared to the hanging wall (chlorite-sericite schist) and foot wall (metalimestone) units. It seems that, LREE enrichment can be related to the circulation of SO4-2, CO2 -bearing fluids as well as regional metamorphic in the Qolqoleh shear zone. The presence of positive and negative Eu anomaly in the metavolcanic rocks is due to the low and advance alteration respectively. The negative anomaly is related to plagioclase alteration in these rocks. The lack of Eu anomaly in the hanging wall and foot wall indicate that these rocks are unaltered.https://ijp.ui.ac.ir/article_16097_33e739ceceacc0e4e467a4c64cd7b2c7.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Study cause of tertrad effect in REE pattern in Misho A-type granitoides Complex, NW of IranStudy cause of tertrad effect in REE pattern in Misho A-type granitoides Complex, NW of Iran657816099FAMaryamAhankoubAhmadJahangiriدانشگاه تبریز گروه علوم زمین احمد جهانگیریMohsenMoayyedJournal Article20160614A-Type granitoides of the East Misho, are per-aluminous to sub-aluminous rocks that formed by partial melting of lower crustal rocks. Their essential composed of quartz, K-Feldspar, plagioclase, amphibole and biotite and accessory minerals including alanite, zircon, apatite and Fe-oxide. REE normalize conderite pattern of the granitoids show the M-type tetrad effect and strong Eu depletion. All of petrographic and geochemical data show that both fractionation and crystallization REE-rich minerals and reaction of magma- fluids in late crystallization phenomena are the most important factors for tetrad effect formation in misho granitoides.A-Type granitoides of the East Misho, are per-aluminous to sub-aluminous rocks that formed by partial melting of lower crustal rocks. Their essential composed of quartz, K-Feldspar, plagioclase, amphibole and biotite and accessory minerals including alanite, zircon, apatite and Fe-oxide. REE normalize conderite pattern of the granitoids show the M-type tetrad effect and strong Eu depletion. All of petrographic and geochemical data show that both fractionation and crystallization REE-rich minerals and reaction of magma- fluids in late crystallization phenomena are the most important factors for tetrad effect formation in misho granitoides.https://ijp.ui.ac.ir/article_16099_8eaa18932c4642dff16fd16b7bf65b80.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Petrology, Geochemistry and Tectonic setting of Javaherdasht Cretaceous gabbro in the north part of Alborz Mountains, East of Guilan, North of Iran: A part of ophiolite sequence or intra-continental rift?Petrology, Geochemistry and Tectonic setting of Javaherdasht Cretaceous gabbro in the north part of Alborz Mountains, East of Guilan, North of Iran: A part of ophiolite sequence or intra-continental rift?799416100FAShahrouzHaghnazarاستان گیلان - لاهیجان- خیابان کاشف شرقی- انتهای خیابان شقایق- دانشگاه آزاد اسلامی واحد لاهیجان- گروه زمین شناسی صندوق پستی : 1616Journal Article20160614The Cretaceous gabbros located in Javaherdasht area in the northern part of Alborz Mountains, south of Guilan province. These gabbros show layered structure at the bottom and the isotropic structure at the top. From the mineralogical point of view, they have plagioclase, augite, olivine, biotite and magnetite. Geochemically, they belong to transitional magmatic series. Positive anomaly of Pb, K, Th, Rb and negative anomaly of Ba, Zr, Nb and P indicate contamination with continental crust. Tectonic setting diagrams of these gabbros suggest a continental intraplate environment, also the value of (Nb/Nb*)pm ~0.89 in the studied gabbros is similar to intra-continental rift basalts with crustal contamination. The REE pattern of the studied gabbros is also similar to transitional-sub alkalic intracontinental rift basalts and the values of (Ce/Yb)N ~3.9 and (Dy/Yb)N ~1.3 indicate the presence of spinel in their mantle source. The high ratio of Th/Nb and ïNb>0 prove that the magma is derived from MORB mantle plumes (P-MORB) which has been contaminated with continental crust.The Cretaceous gabbros located in Javaherdasht area in the northern part of Alborz Mountains, south of Guilan province. These gabbros show layered structure at the bottom and the isotropic structure at the top. From the mineralogical point of view, they have plagioclase, augite, olivine, biotite and magnetite. Geochemically, they belong to transitional magmatic series. Positive anomaly of Pb, K, Th, Rb and negative anomaly of Ba, Zr, Nb and P indicate contamination with continental crust. Tectonic setting diagrams of these gabbros suggest a continental intraplate environment, also the value of (Nb/Nb*)pm ~0.89 in the studied gabbros is similar to intra-continental rift basalts with crustal contamination. The REE pattern of the studied gabbros is also similar to transitional-sub alkalic intracontinental rift basalts and the values of (Ce/Yb)N ~3.9 and (Dy/Yb)N ~1.3 indicate the presence of spinel in their mantle source. The high ratio of Th/Nb and ïNb>0 prove that the magma is derived from MORB mantle plumes (P-MORB) which has been contaminated with continental crust.https://ijp.ui.ac.ir/article_16100_419d63a8997d3584536e8e82f64e1e21.pdfUniversity of IsfahanPetrological Journal2228-521031020121121Petrography and mineral chemistry of Eocene volcanic in the southwest of Jandaq (northeast of Isfahan)Petrography and mineral chemistry of Eocene volcanic in the southwest of Jandaq (northeast of Isfahan)9510716103FALeilaMahmoudabadiSeyed MohsenTabatabei ManeshGhodratTorabiJournal Article20160614In the south west of Jandaq area, the Eocene volcanic rocks crop out, near the Doruneh Fault in a large area. These rocks are composed predominantly of basalt, quartz andesite, andesite, dacite and latitewith porphyritic, microliticporphyritic and hyaloporphyric textures. The main constituents are plagioclase, amphibole, clinopyroxene, quartz, minor alkali feldspar and biotite and opaque minerals as accessory minerals. The secondary minerals are opaque, sericite, calcite and chlorite. The composition of the plagioclase ranges from andesine to labradorite, the clinopyroxene is diopside-augite and the amphiboles are magnesio-hastingsite some plagioclase phenocrysts show oscillatory zoning. The study of chemical composition of clinopyroxenes classifies these rocks as sub-alkaline series and volcanic arc. The geothermometry of clinopyroxene reveal the temperature of 941-959 ºC for pressure of 1-10 kbars. Clinopyroxenes barometry point to their formation in defferent depths during their ascending. The Hlb-Plg thermometry shows the temperature of 858-941 ºC for pressure of 1-10 kbars. The high volume of water in the crystalization environment of the pyroxenes as well as variations on AlIV+Na/ AlIV+2Ti+Cr diagram indicate the high oxygen fugacity of the environment. Field observations and some petrographic evidences demonstrate traces of hydrothermal alteration.In the south west of Jandaq area, the Eocene volcanic rocks crop out, near the Doruneh Fault in a large area. These rocks are composed predominantly of basalt, quartz andesite, andesite, dacite and latitewith porphyritic, microliticporphyritic and hyaloporphyric textures. The main constituents are plagioclase, amphibole, clinopyroxene, quartz, minor alkali feldspar and biotite and opaque minerals as accessory minerals. The secondary minerals are opaque, sericite, calcite and chlorite. The composition of the plagioclase ranges from andesine to labradorite, the clinopyroxene is diopside-augite and the amphiboles are magnesio-hastingsite some plagioclase phenocrysts show oscillatory zoning. The study of chemical composition of clinopyroxenes classifies these rocks as sub-alkaline series and volcanic arc. The geothermometry of clinopyroxene reveal the temperature of 941-959 ºC for pressure of 1-10 kbars. Clinopyroxenes barometry point to their formation in defferent depths during their ascending. The Hlb-Plg thermometry shows the temperature of 858-941 ºC for pressure of 1-10 kbars. The high volume of water in the crystalization environment of the pyroxenes as well as variations on AlIV+Na/ AlIV+2Ti+Cr diagram indicate the high oxygen fugacity of the environment. Field observations and some petrographic evidences demonstrate traces of hydrothermal alteration.https://ijp.ui.ac.ir/article_16103_866c504d51e6b4f11584d6f9d1e66868.pdf