Ali Asghar Calagari | University of Tabriz (original) (raw)

Papers by Ali Asghar Calagari

Geochemistry and genesis of bauxite-laterite deposits. Finished research works 1-Studies on alter... more Geochemistry and genesis of bauxite-laterite deposits. Finished research works 1-Studies on alteration and mineralization of precious and rare elements in Bozlokh-Gharedash area, kharvana, East-Azarbaidjan. 2-Exploration (for Ni, Co, Cr) and mineralogical, petrological, and geochemical investigations of mafic igneous rocks in Misho mountain range, Marand, East-Azarbaidjan, Iran. 3-Study of lamrophyric dikes in Eslamy island, Urumieh lake, East-Azarbaidjan, Iran. 4-Studis of calcic skarn in relation to sub-volcanic granitoidic body (hosting porphyry copper deposit) at east of Sungun-Chay, NW Ahar, East-Azarbaidjan, Iran. 5-Economic assessment and investigation of mineralogy, geochemistry, and genesis of bauxite-laterite horizons in Kanisheeteh area, east of Bukan, West-Azarbaidjan, Iran. 6-Geochemical investigations on Cambrian sandstones in SW Mashhad. 7-Internal assessment of Geology Department at Tabriz University. Dissertations Calagari, A. A., 1981. The geology of sulfide mineralization of the Sand Creek drainage, Spokane Indian Reservation, Spokane, Washington. M.Sc. , 127p. Calagari, A. A., 1997. Geochemical, stable isotope, noble gas, and fluid inclusion studies of mineralization and alteration at Sungun porphyry copper deposit, East-Azarbaidjan, Iran: Implication for genesis. Ph.D. thesis, genesis of the volcanic-hosted hydrothermal iron ore deposit in Somea, NW Iran. Arabian Journal of Geosciences, 11: 82. Abedini, A., Calagari, A. A., and Rezaei Azizi, M. 2018. The tetrad-effect in rare earth elements distribution patterns of titanium-rich bauxites: Tehrani, P, Calagari, A. A., Abedini, A., Mazlumi, A., 2013. The geological, mineralogical, alteration features, and rare earth elements (REEs) geochemistry of Neyzar iron deposit, southwest of Mashhad, northeast of Iran. Iranian Society of Crystallography and Mineralogy, Vol. 21 (2), pp. 229-242. . Abedini, A., Calagari, A. A., 2013. Petrography and mineralogical and geochemical control on distribution of major, minor, and trace elements in bauxitic-lateritic deposit of the NE Malekan, East-Azarbaidjan province, NW Iran. ., 2012. Halogen signatures of biotites from the Maher-Abad porphyry copper deposit, Iran: Characterization of volatiles in syn-to post-magmatic hydrothermal fluids. ., 2012. Studies of the porphyry-type alteration zones and geochemical behavior of trace and rare earth elements within them in Kighal, north of Varzeghan, East-Azarbaidjan, Iran.

Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghaz... more Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghazvin province, west of central Iran. It consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of Ruteh (Permian) and Elika (Triassic) carbonate formations. Petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidiomorphic-granular, nodular, and skeletal textures indicative of authigenic origin. Weathering of andesitic parent rocks led to the formation of Ferruginous laterite, bauxitic clay, and siliceous bauxite. Mass change calculations of elements indicate that Si, and Ba were depleted during bauxitization and Al, Ti, Zr, Nb, Hf, Ga, U, Th, V, and Cr were enriched. However, Fe, Y, Rb, Sr, Co, Ni, LREEs, and HREEs experienced leaching-fixation mechanism during the development of the residual system. Based upon obtained data, the available organic matters, pH variations in weathering solutions, adsorption process, functioning of carbonate bedrock as a geochemical barrier, existing in resistant minerals, and fixation in the neomorphic phases have been shown to play significant role in distribution of trace and rare earth elements. Further geochemical considerations indicate that minerals such as monazite, rhabdophane, belovite, churchite, and xenotime are the potential hosts for rare earth elements in Biglar bauxite deposit.

Arabian Journal of Geosciences, 2016

Periodico Di Mineralogia, Apr 1, 2013

Ferruginous bauxite horizon of Kanigorgeh is located ~ 20 km northeast of Bukan, West-Azarbaidjan... more Ferruginous bauxite horizon of Kanigorgeh is located ~ 20 km northeast of Bukan, West-Azarbaidjan province, northwest Iran. The horizon is a part of the Irano-Himalayan karst bauxite belt that was developed in a form of 8 discontinuous stratified layers and lenses varying in thicknesses (5-17 m) with extending over 3.2 km along the contact of Permian carbonates, Triassic dolomites. In this study, parental affinity and controlling factors of elements distribution in the bauxite ores are surveyed by applying analytical mineralogy, mass and volume changes calculations (method of isocon), elemental ratios, and correlation coefficients. Mineralogical analyses reveal that diaspore, hematite, and kaolinite are the major minerals in the ores with lesser and variable amounts of boehmite, goethite, muscovite-illite, rutile, and montmorillonite. In contrast to the presence of diasporic-boehmitic mineralogical composition in ores, the geochemical data (i.e., ratios of Pb/Y, Ga/Pb, Zr/Pb, and Cr/Ni), testify to gibbsitic composition for the original aluminum hydroxides. Microscopic studies and geochemical characteristics of major and trace elements indicate that the ores were formed authigenically by the alteration and weathering of basaltic parent rocks. Mass change calculations suggests that enrichment of many elements in the ores resulted by losing Si, Ca, K, Na, Mg, and P during weathering of plagioclase, K-feldspar, ferromagnesians, and apatite. In addition, variable amounts of Co, Sr, and Ba were lost during bauxitization. Geochemical considerations prove that distribution of major, minor, trace, and rare earth elements in the studied ores were principally controlled by factors such as cation exchanges, adsorption, increasing of pH in weathering solutions due to buffering by carbonate bedrocks, scavenging by Fe-oxides and hydroxides, isomorphic substitutions, co-precipitation, and differences in stability of primary minerals.

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2015

Maden Tetkik ve Arama Dergisi, 2014

Bauxite deposit of Permo-Triassic age in northeast of Bukan was developed stratiformly along the ... more Bauxite deposit of Permo-Triassic age in northeast of Bukan was developed stratiformly along the boundary between Ruteh and Elika formations, and includes four distinct rock units. This deposit was affected by tectonic and morphological processes. Mineralogical and geochemical investigations showed that during weathering processes, two mechanisms of ferrugenization and deferrugenization played crucial role in formation of minerals such as diaspore, boehmite, hematite, goethite, kaolinite, pyrophyllite, clinochlore, illite, montmorillonite, anatase, rutile, albite, sanidine, quartz, and calcite in this deposit. By taking notice of field evidence and of mineralogical and geochemical data, the basalts (whose remnants are still present along the contact of this deposit with carbonate bedrock) are the potential parent rock of this deposit. The distribution pattern of REEs (normalized to chondrite and basaltic parent rock) along with anomaly variations of Eu, Ce, and (La/Yb) N indicates differentiation of LREEs from HREEs during bauxitization processes. Further geochemical considerations indicate that the concentrations of LREEs were occurred by hematite, goethite, manganese oxides, cerianite, and secondary phosphates (rhabdophane, vitusite, gorceixite, monazite) and of HREEs by clay minerals, rutile, anatase, zircon, euxenite, and fergusonite. Incorporation of the results obtained from mineralogical and geochemical investigations suggests that in addition to factors such as pH of weathering solutions, ionic potential, composition of the parent rock, and fixation by residual minerals, adsorption processes also played crucial role in enrichment of REEs during moderate to intense lateritization in the study area.

Aghadjari bauxite deposit is located in ~15km south of Shahindezh, West-Azarbaidjan province. Thi... more Aghadjari bauxite deposit is located in ~15km south of Shahindezh, West-Azarbaidjan province. This deposit was developed as stratiform lenses along the contact of Rutheh and Elika carbonate formations. Bauxitization processes led to the formation of boehmite, diaspore, kaolinite, pyrophyllite, illite, hematite, goethite, anatase, rutile, and quartz. Ferrugenization and deferrugenization mechanisms are two important factors controlling distribution of elements in this deposit. Mafic igneous rocks are the potential protolith. Obtained data show that elements such as Al, Ti, Fe, Zr, Hf, REE, and Nb moved down from the upper horizons to the lower parts of residual system by organic complexes during kaolinization processes. The carbonate bedrocks played dual roles in distribution of elements in this deposit. These rocks neutralized the acidic weathering solutions causing an increase in deposition of iron oxides and hydroxides which in turn due to their adsorption capacity caused considerable concentration of Cr, Co, and LREE in lower parts of the bauxite horizon. On the other hand, the carbonates by forming stable ionic complexes with HREEs caused these elements to drain out of the residual system.

The porphyry copper deposit at Sungun is located in East Azarbaidjan, NW of Iran. The Sungun porp... more The porphyry copper deposit at Sungun is located in East Azarbaidjan, NW of Iran. The Sungun porphyries (Oligo-Miocene) occur as stocks and dikes and intruded a series of Oligocene pyroclastics and lavas, Eocene arenaceous-argillaceous rocks, and Upper Cretaceous carbonates. The porphyry stocks are divided into two groups, 1) porphyry stocks I (quartz monzo-diorite) and 2) porphyry stock II (quartz monzonite, granodiorite, and granite). Porphyry stock II hosts the copper and molybdenum ores. Numerous and various cross-cutting veinlets and micro-veinlets of quartz, sulfides, sericite, carbonates, and sulfates were developed in porphyry stock II. Three distinct types of hydrothermal alterations and sulfide mineralizations are recognized at Sungun; 1) hypogene, 2) contact metasomatic, and 3) supergene. The vertical variations in concentration of 12 elements (S, Cu, Mo, K, Rb, Ca, Sr, Na, Mg, Fe, Al, and Si) across various hypogene alteration zones at Sungun demonstrate that S, Cu, Mo, Fe, K, and Rb are mainly concentrated in the phyllic and potassic-phyllic zones where the abundance of Ca, Sr, Mg, and Na are appreciably low relative to the potassic zone. The values of Al and Si are relatively high in the supergene zones and their abundance gradually decrease downward toward the potassic zone. The copper and molybdenum are substantially localized in the phyllic and potassic-phyllic zones particularly in the central part of the mineralized porphyry stock where the rocks underwent severe stockwork-type fracturing and micro-fracturing. Their concentrations are relatively low in the potassic zone.

Incheh granitoid intrusive body is located in east of Heris, East-Azarbaidjan. It intruded the ol... more Incheh granitoid intrusive body is located in east of Heris, East-Azarbaidjan. It intruded the older rock units including the Sonajil sub-volcanic stock (upper Eocene-lower Oligocene) of micro-diorite porphyry composition. The Incheh intrusive ranges in composition from diorite through syeno-diorite to quartz-diorite. The major constituent minerals include plagioclase, hornblende, and pyroxene accompanied by minor amounts of biotite, alkali-feldspars, quartz, olivine, epidote, and tourmaline. These rocks feature dominantly porphyritic texture, however, granular, trachytoid, and ophitic textures are also sporadically present. The Incheh intrusive has been evolved by the influence of magmatic differentiation, fractional crystallization, assimilation, and crustal contamination. Chemical analyses show that the rocks of Incheh intrusive are chiefly metaluminous, and belong to high-K calc-alkaline to shoshonitic magma series. From the viewpoint of tectonic environment, the Incheh body was emplaced in a post-collision volcanic arc and an active continental margin setting.

Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghaz... more Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghazvin province, west of central Iran. It consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of Ruteh (Permian) and Elika (Triassic) carbonate formations. Petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidio-morphic-granular, nodular, and skeletal textures indicative of authigenic origin. Weathering of andesitic parent rocks led to the formation of Ferruginous laterite, bauxitic clay, and siliceous bauxite. Mass change calculations of elements indicate that Si, and Ba were depleted during bauxitization and Al, Ti, Zr, Nb, Hf, Ga, U, Th, V, and Cr were enriched. However, Fe, Y, Rb, Sr, Co, Ni, LREEs, and HREEs experienced leaching-fixation mechanism during the development of the residual system. Based upon obtained data, the available organic matters, pH variations in weathering solutions, adsorption proce...

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2015

Mehredjan bentonite deposit is located~ 33 km southeast of Khoor in Isfehan province. It includes... more Mehredjan bentonite deposit is located~ 33 km southeast of Khoor in Isfehan province. It includes 15 discrete outcrops and occurs as layered and massive forms within a volcano-clastic sequence. Bentonitization process was accompanied with development of minerals ...

Abstract Laloon Formation (lower Cambrain) in southwest of Mashhad is characterized by a sequence... more Abstract Laloon Formation (lower Cambrain) in southwest of Mashhad is characterized by a sequence of layers of sandstone (quartz-arenite, sub-litharenite, and Fe-bearing sand) and conglomerate. Petrographic investigations show that quartz is the main detrital mineral in these rocks accompanied by lesser amounts of chert, feldspar, mica, and zircon. Based upon geochemical studies, tectonic setting of these sandstones is the inactive continental margin environment. Values of chemical index of alteration (CIA) (61.51 to 74.38%) and plagioclase index of alteration (PIA) (53.54 to 67.07%) indicate that these sandstones were evolved under moderate weathering conditions. Geochemical considerations reveal a felsic to intermediate igneous provenance for these rocks. By combining the petrographical and geochemical data, it can be deduced that these rocks were likely derived from the erosion of low-grade metamorphosed acid igneous bodies and their related pegmatitic veins. These rocks have sui...

Abstract: Neyzar iron deposit is located ~50 km southwest of Mashhad, northeast of Iran. It was d... more Abstract: Neyzar iron deposit is located ~50 km southwest of Mashhad, northeast of Iran. It was developed as layered and discontinuous lenses in a fault zone within quartz-arenite and sub-litharenite sandstones of Lalun formation (lower Cambrian). Mineralographical studies show that hematite is the principal iron ore mineral accompanied by goethite and lesser amounts of pyrite. Microscopic examinations confirm the presence of skeletal, relic replacement, marginal replacement, and pseudomorphic textures within the ores. Based upon petrographic data two series of alteration minerals, hypogene (sericite, pyrite, pyrophyllite, barite, chalcedony, and calcite) and supergene (goethite, jarosite, gypsum, limonite, and hematite) were developed in this deposit. By noting the results obtained from field works and mineralographical and geochemical studies, it appears that the evolution of the studied ores is genetically related to the host rocks. Both hydrothermal processes and fault systems (...

Geochemistry and genesis of bauxite-laterite deposits. Finished research works 1-Studies on alter... more Geochemistry and genesis of bauxite-laterite deposits. Finished research works 1-Studies on alteration and mineralization of precious and rare elements in Bozlokh-Gharedash area, kharvana, East-Azarbaidjan. 2-Exploration (for Ni, Co, Cr) and mineralogical, petrological, and geochemical investigations of mafic igneous rocks in Misho mountain range, Marand, East-Azarbaidjan, Iran. 3-Study of lamrophyric dikes in Eslamy island, Urumieh lake, East-Azarbaidjan, Iran. 4-Studis of calcic skarn in relation to sub-volcanic granitoidic body (hosting porphyry copper deposit) at east of Sungun-Chay, NW Ahar, East-Azarbaidjan, Iran. 5-Economic assessment and investigation of mineralogy, geochemistry, and genesis of bauxite-laterite horizons in Kanisheeteh area, east of Bukan, West-Azarbaidjan, Iran. 6-Geochemical investigations on Cambrian sandstones in SW Mashhad. 7-Internal assessment of Geology Department at Tabriz University. Dissertations Calagari, A. A., 1981. The geology of sulfide mineralization of the Sand Creek drainage, Spokane Indian Reservation, Spokane, Washington. M.Sc. , 127p. Calagari, A. A., 1997. Geochemical, stable isotope, noble gas, and fluid inclusion studies of mineralization and alteration at Sungun porphyry copper deposit, East-Azarbaidjan, Iran: Implication for genesis. Ph.D. thesis, genesis of the volcanic-hosted hydrothermal iron ore deposit in Somea, NW Iran. Arabian Journal of Geosciences, 11: 82. Abedini, A., Calagari, A. A., and Rezaei Azizi, M. 2018. The tetrad-effect in rare earth elements distribution patterns of titanium-rich bauxites: Tehrani, P, Calagari, A. A., Abedini, A., Mazlumi, A., 2013. The geological, mineralogical, alteration features, and rare earth elements (REEs) geochemistry of Neyzar iron deposit, southwest of Mashhad, northeast of Iran. Iranian Society of Crystallography and Mineralogy, Vol. 21 (2), pp. 229-242. . Abedini, A., Calagari, A. A., 2013. Petrography and mineralogical and geochemical control on distribution of major, minor, and trace elements in bauxitic-lateritic deposit of the NE Malekan, East-Azarbaidjan province, NW Iran. ., 2012. Halogen signatures of biotites from the Maher-Abad porphyry copper deposit, Iran: Characterization of volatiles in syn-to post-magmatic hydrothermal fluids. ., 2012. Studies of the porphyry-type alteration zones and geochemical behavior of trace and rare earth elements within them in Kighal, north of Varzeghan, East-Azarbaidjan, Iran.

Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghaz... more Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghazvin province, west of central Iran. It consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of Ruteh (Permian) and Elika (Triassic) carbonate formations. Petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidiomorphic-granular, nodular, and skeletal textures indicative of authigenic origin. Weathering of andesitic parent rocks led to the formation of Ferruginous laterite, bauxitic clay, and siliceous bauxite. Mass change calculations of elements indicate that Si, and Ba were depleted during bauxitization and Al, Ti, Zr, Nb, Hf, Ga, U, Th, V, and Cr were enriched. However, Fe, Y, Rb, Sr, Co, Ni, LREEs, and HREEs experienced leaching-fixation mechanism during the development of the residual system. Based upon obtained data, the available organic matters, pH variations in weathering solutions, adsorption process, functioning of carbonate bedrock as a geochemical barrier, existing in resistant minerals, and fixation in the neomorphic phases have been shown to play significant role in distribution of trace and rare earth elements. Further geochemical considerations indicate that minerals such as monazite, rhabdophane, belovite, churchite, and xenotime are the potential hosts for rare earth elements in Biglar bauxite deposit.

Arabian Journal of Geosciences, 2016

Periodico Di Mineralogia, Apr 1, 2013

Ferruginous bauxite horizon of Kanigorgeh is located ~ 20 km northeast of Bukan, West-Azarbaidjan... more Ferruginous bauxite horizon of Kanigorgeh is located ~ 20 km northeast of Bukan, West-Azarbaidjan province, northwest Iran. The horizon is a part of the Irano-Himalayan karst bauxite belt that was developed in a form of 8 discontinuous stratified layers and lenses varying in thicknesses (5-17 m) with extending over 3.2 km along the contact of Permian carbonates, Triassic dolomites. In this study, parental affinity and controlling factors of elements distribution in the bauxite ores are surveyed by applying analytical mineralogy, mass and volume changes calculations (method of isocon), elemental ratios, and correlation coefficients. Mineralogical analyses reveal that diaspore, hematite, and kaolinite are the major minerals in the ores with lesser and variable amounts of boehmite, goethite, muscovite-illite, rutile, and montmorillonite. In contrast to the presence of diasporic-boehmitic mineralogical composition in ores, the geochemical data (i.e., ratios of Pb/Y, Ga/Pb, Zr/Pb, and Cr/Ni), testify to gibbsitic composition for the original aluminum hydroxides. Microscopic studies and geochemical characteristics of major and trace elements indicate that the ores were formed authigenically by the alteration and weathering of basaltic parent rocks. Mass change calculations suggests that enrichment of many elements in the ores resulted by losing Si, Ca, K, Na, Mg, and P during weathering of plagioclase, K-feldspar, ferromagnesians, and apatite. In addition, variable amounts of Co, Sr, and Ba were lost during bauxitization. Geochemical considerations prove that distribution of major, minor, trace, and rare earth elements in the studied ores were principally controlled by factors such as cation exchanges, adsorption, increasing of pH in weathering solutions due to buffering by carbonate bedrocks, scavenging by Fe-oxides and hydroxides, isomorphic substitutions, co-precipitation, and differences in stability of primary minerals.

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2015

Maden Tetkik ve Arama Dergisi, 2014

Bauxite deposit of Permo-Triassic age in northeast of Bukan was developed stratiformly along the ... more Bauxite deposit of Permo-Triassic age in northeast of Bukan was developed stratiformly along the boundary between Ruteh and Elika formations, and includes four distinct rock units. This deposit was affected by tectonic and morphological processes. Mineralogical and geochemical investigations showed that during weathering processes, two mechanisms of ferrugenization and deferrugenization played crucial role in formation of minerals such as diaspore, boehmite, hematite, goethite, kaolinite, pyrophyllite, clinochlore, illite, montmorillonite, anatase, rutile, albite, sanidine, quartz, and calcite in this deposit. By taking notice of field evidence and of mineralogical and geochemical data, the basalts (whose remnants are still present along the contact of this deposit with carbonate bedrock) are the potential parent rock of this deposit. The distribution pattern of REEs (normalized to chondrite and basaltic parent rock) along with anomaly variations of Eu, Ce, and (La/Yb) N indicates differentiation of LREEs from HREEs during bauxitization processes. Further geochemical considerations indicate that the concentrations of LREEs were occurred by hematite, goethite, manganese oxides, cerianite, and secondary phosphates (rhabdophane, vitusite, gorceixite, monazite) and of HREEs by clay minerals, rutile, anatase, zircon, euxenite, and fergusonite. Incorporation of the results obtained from mineralogical and geochemical investigations suggests that in addition to factors such as pH of weathering solutions, ionic potential, composition of the parent rock, and fixation by residual minerals, adsorption processes also played crucial role in enrichment of REEs during moderate to intense lateritization in the study area.

Aghadjari bauxite deposit is located in ~15km south of Shahindezh, West-Azarbaidjan province. Thi... more Aghadjari bauxite deposit is located in ~15km south of Shahindezh, West-Azarbaidjan province. This deposit was developed as stratiform lenses along the contact of Rutheh and Elika carbonate formations. Bauxitization processes led to the formation of boehmite, diaspore, kaolinite, pyrophyllite, illite, hematite, goethite, anatase, rutile, and quartz. Ferrugenization and deferrugenization mechanisms are two important factors controlling distribution of elements in this deposit. Mafic igneous rocks are the potential protolith. Obtained data show that elements such as Al, Ti, Fe, Zr, Hf, REE, and Nb moved down from the upper horizons to the lower parts of residual system by organic complexes during kaolinization processes. The carbonate bedrocks played dual roles in distribution of elements in this deposit. These rocks neutralized the acidic weathering solutions causing an increase in deposition of iron oxides and hydroxides which in turn due to their adsorption capacity caused considerable concentration of Cr, Co, and LREE in lower parts of the bauxite horizon. On the other hand, the carbonates by forming stable ionic complexes with HREEs caused these elements to drain out of the residual system.

The porphyry copper deposit at Sungun is located in East Azarbaidjan, NW of Iran. The Sungun porp... more The porphyry copper deposit at Sungun is located in East Azarbaidjan, NW of Iran. The Sungun porphyries (Oligo-Miocene) occur as stocks and dikes and intruded a series of Oligocene pyroclastics and lavas, Eocene arenaceous-argillaceous rocks, and Upper Cretaceous carbonates. The porphyry stocks are divided into two groups, 1) porphyry stocks I (quartz monzo-diorite) and 2) porphyry stock II (quartz monzonite, granodiorite, and granite). Porphyry stock II hosts the copper and molybdenum ores. Numerous and various cross-cutting veinlets and micro-veinlets of quartz, sulfides, sericite, carbonates, and sulfates were developed in porphyry stock II. Three distinct types of hydrothermal alterations and sulfide mineralizations are recognized at Sungun; 1) hypogene, 2) contact metasomatic, and 3) supergene. The vertical variations in concentration of 12 elements (S, Cu, Mo, K, Rb, Ca, Sr, Na, Mg, Fe, Al, and Si) across various hypogene alteration zones at Sungun demonstrate that S, Cu, Mo, Fe, K, and Rb are mainly concentrated in the phyllic and potassic-phyllic zones where the abundance of Ca, Sr, Mg, and Na are appreciably low relative to the potassic zone. The values of Al and Si are relatively high in the supergene zones and their abundance gradually decrease downward toward the potassic zone. The copper and molybdenum are substantially localized in the phyllic and potassic-phyllic zones particularly in the central part of the mineralized porphyry stock where the rocks underwent severe stockwork-type fracturing and micro-fracturing. Their concentrations are relatively low in the potassic zone.

Incheh granitoid intrusive body is located in east of Heris, East-Azarbaidjan. It intruded the ol... more Incheh granitoid intrusive body is located in east of Heris, East-Azarbaidjan. It intruded the older rock units including the Sonajil sub-volcanic stock (upper Eocene-lower Oligocene) of micro-diorite porphyry composition. The Incheh intrusive ranges in composition from diorite through syeno-diorite to quartz-diorite. The major constituent minerals include plagioclase, hornblende, and pyroxene accompanied by minor amounts of biotite, alkali-feldspars, quartz, olivine, epidote, and tourmaline. These rocks feature dominantly porphyritic texture, however, granular, trachytoid, and ophitic textures are also sporadically present. The Incheh intrusive has been evolved by the influence of magmatic differentiation, fractional crystallization, assimilation, and crustal contamination. Chemical analyses show that the rocks of Incheh intrusive are chiefly metaluminous, and belong to high-K calc-alkaline to shoshonitic magma series. From the viewpoint of tectonic environment, the Incheh body was emplaced in a post-collision volcanic arc and an active continental margin setting.

Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghaz... more Biglar Permo-Triassic bauxite deposit is located in ~15 km northwest of Abgarm, southwest of Ghazvin province, west of central Iran. It consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of Ruteh (Permian) and Elika (Triassic) carbonate formations. Petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidio-morphic-granular, nodular, and skeletal textures indicative of authigenic origin. Weathering of andesitic parent rocks led to the formation of Ferruginous laterite, bauxitic clay, and siliceous bauxite. Mass change calculations of elements indicate that Si, and Ba were depleted during bauxitization and Al, Ti, Zr, Nb, Hf, Ga, U, Th, V, and Cr were enriched. However, Fe, Y, Rb, Sr, Co, Ni, LREEs, and HREEs experienced leaching-fixation mechanism during the development of the residual system. Based upon obtained data, the available organic matters, pH variations in weathering solutions, adsorption proce...

Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, 2015

Mehredjan bentonite deposit is located~ 33 km southeast of Khoor in Isfehan province. It includes... more Mehredjan bentonite deposit is located~ 33 km southeast of Khoor in Isfehan province. It includes 15 discrete outcrops and occurs as layered and massive forms within a volcano-clastic sequence. Bentonitization process was accompanied with development of minerals ...

Abstract Laloon Formation (lower Cambrain) in southwest of Mashhad is characterized by a sequence... more Abstract Laloon Formation (lower Cambrain) in southwest of Mashhad is characterized by a sequence of layers of sandstone (quartz-arenite, sub-litharenite, and Fe-bearing sand) and conglomerate. Petrographic investigations show that quartz is the main detrital mineral in these rocks accompanied by lesser amounts of chert, feldspar, mica, and zircon. Based upon geochemical studies, tectonic setting of these sandstones is the inactive continental margin environment. Values of chemical index of alteration (CIA) (61.51 to 74.38%) and plagioclase index of alteration (PIA) (53.54 to 67.07%) indicate that these sandstones were evolved under moderate weathering conditions. Geochemical considerations reveal a felsic to intermediate igneous provenance for these rocks. By combining the petrographical and geochemical data, it can be deduced that these rocks were likely derived from the erosion of low-grade metamorphosed acid igneous bodies and their related pegmatitic veins. These rocks have sui...

Abstract: Neyzar iron deposit is located ~50 km southwest of Mashhad, northeast of Iran. It was d... more Abstract: Neyzar iron deposit is located ~50 km southwest of Mashhad, northeast of Iran. It was developed as layered and discontinuous lenses in a fault zone within quartz-arenite and sub-litharenite sandstones of Lalun formation (lower Cambrian). Mineralographical studies show that hematite is the principal iron ore mineral accompanied by goethite and lesser amounts of pyrite. Microscopic examinations confirm the presence of skeletal, relic replacement, marginal replacement, and pseudomorphic textures within the ores. Based upon petrographic data two series of alteration minerals, hypogene (sericite, pyrite, pyrophyllite, barite, chalcedony, and calcite) and supergene (goethite, jarosite, gypsum, limonite, and hematite) were developed in this deposit. By noting the results obtained from field works and mineralographical and geochemical studies, it appears that the evolution of the studied ores is genetically related to the host rocks. Both hydrothermal processes and fault systems (...