غلامحسین شمعانیان

In order to find the relationship between porphyry copper depositions with faulting systems, the Aliabad porphyry and Darre Zereshk Porphyry- Skarn ores were selected as a case studies in Uramia- Dokhtar Magmatic Belt,. In this research, discovering this correlation procedure was performed by using surface and subsurface data (i.e. drilling data as geotechnical and Cu-percentage data) from Aliabad and Darre Zereshk mine districts. The results show that RQD criteria extracted from fault zones have a good correlation with surface faults which are identified by field investigations and Remote Sensing techniques. Also, the copper enriched was observed along fault zones and therefore, the relationship between porphyry copper deposits and fault zones is approved.

The Separdeh laterite deposit in the western part of Alborz is about 114 km from the Ramsar city in Mazandaran province. This deposit is located between Triassic limestones (Elika Formation) and Jurassic sandstones (Shemshak Formation). There has been no comprehensive study on the Separdeh deposit. Only studies included 1: 100,000 scale geological map of Javaherdeh and identification of bauxite-laterite and refractory materials of Gilan province by Geological Survey of Iran. Therefore, this paper attempts to study the physicochemical conditions of formation, factors of ore type development and factors affecting the distribution, mobility and differentiation of rare earth elements, Ce and Eu anomalies, and determining the origin of the ore, taking into account the petrographic, mineralogical and geochemical features of the Separdeh deposit.

Based on detailed field observations, 14 ore samples were systematically taken. These were perpendicular to the profile, picked up from the lateritic rocks due to changes in color, texture, and hardness. Thin sections were prepared for textural studies and X-ray diffraction (XRD) analyses of the samples for mineralogical studies at the Iranian Mineral Processing Research Center in Karaj. Geochemical studies of 10 samples were analyzed by ICP-OES and ICP-MS methods to determine the quantities of major and minor earth elements by MS Analytical Company in Canada.

Structural and textural studies in the Separdeh deposit indicate both autochthonous and allochthonous origins for this deposit. Mineralogical investigations revealed that minerals such as siderite, chamosite, kaolinite, boehmite, diaspore, hematite, goethite, clinochlore, and anatase are the main mineral phases accompanied by of minor phase like rutile, moscovite, and lipidocrocite. This mineral assemblage suggests that both underground waters with reducing-alkaline nature and surface waters with oxidizing-acidic nature played an important role in development of this deposit. Based upon chemical analyses, REE values of the ores vary from 58.91 to 846.72 ppm. Values of La/Y, Eu/Eu*, and Ce/Ce* of the ores are within the range of 0.34-3.76, 0.76-1.24, and 0.92-2.41, respectively. Geochemical studies showed that changes in the physico-chemical conditions of formation environment (pH and Eh), carbonate bed rock as a geochemical barrier, complexation with carbonate ligands, difference in the stability of minerals carrying rare earth elements (REEs), and fixation in neomorph phases, play important roles in distribution and mobility of REEs during the formation and evolution of the lateritic horizon at Separdeh. In addition, the Eu anomalies along with ratios of TiO2/Al2O3 and Sm/Nd indicate that upper Triassic rocks with andesitic to basaltic composition could be the potential precursor for this deposit.

Textural, mineralogical and geochemical studies show that the Separdeh deposit is formed in two stages. In the first stage, authigenic lateritization of the upper Triassic basaltic rocks has occurred, such as alteration and decomposing of silicate minerals and formation of clay, iron and titanium minerals. In the second stage, the transfer of lateritic material into karstic cavities and deposition in lagoon and swampy environments was carried out. These conditions have resulted in the formation of minerals such as pyrite, siderite, and facilitated the process of leaching of rare earth elements from the upper parts of the profile and deposited on the lower parts of the Separdeh deposit.

SummaryThe Module Index (MI = Al2O3/SiO2) is a criterion for determining the ore quality in bauxite deposits. Despite of wide use of the MI, it can not provide reliable criteria for determining of the ore quality due to less statistical attention to outlier data. In this paper, we have introduced the Bauxite Quality Index (BQI) as a new criterion for determining of the bauxite ore quality. We used geochemical data of the Jajarm bauxite deposit to evaluate the ability of the mentioned index. The BQI could be able to classify the ore zones based on the ore quality and economic importance. The BQI would be control the outlier data and reveal relationship between the variables, which are the most important characteristics of this index.IntroductionBauxite is the most important source of aluminum. The quality of bauxite ore depends on mineral composition of the ore which has been calculated by the Module index (Al2O3/SiO2 ). This paper introduced more comprehensive bauxite quality index (BQI) than the MI, using multivariate statistical analysis. We apply geochemical data of the Jajarm bauxite deposit to evaluate the ability of the BQI. Methodology and ApproachesThe BQI is determined based on factor analysis of geochemical data of the Jajarm bauxite deposit. We investigate the relationships between ore quality and alumina-silica contents using the MI and BQI. Then, the economic potential of the ore zones is evaluated by either MI and BQI. Finally, the correlation coefficients of the different parameters are calculated, and the all obtained results are compared and discussed. Results and ConclusionsThe Bauxite Quality Index (BQI) is a new suggested criterion for determination of bauxite ore quality. This criterion reveals hidden relationships of Al2O3 and SiO2 with other variables and outlier data. Comparison of the MI and the BQI indicates that the BQI is more reliable than the MI in recognition of the high grade ore bodies. x.

The Siahrudbar deposit is located about 25 km southwest of Aliabad-Katool city in the Golestan Province, north of Iran. This deposit lies between the Triassic limestone (Elika Formation) and Jurassic sandstone (Shemshak Formation). Mineralogical studies indicate the presence of major minerals such as diaspore, hematite, anatase, kaolinite, and chamosite accompanied by minor minerals such as boehmite, goethite, rutile, calcite, moscovite, clinoclar, quartz, and tridymite. Calculation of enrichment factor showed that the bauxitization processes at Siahrudbar were accompanied by enrichment of elements such as Al, Fe, Ti, V, Cr, Co, Ni, Ga, Th, U, Y, Zr, Ta, Nb, Hf, and REEs. While elements such as Si, Mg, Na, K, P, Ba and Rb were leached out of the profile and suffered depletion. Futhermore, elements like Ca, Mn, Sr and Cs experienced both partial leaching and fixation. Based on the results of geochemical studies, changes in pH and Eh of the weathering solutions, adsorption, presence of organic matter, function of carbonate bed rock as a geochemical barrier, existence in resistant minerals, and fixation in neomorph mineral phases played crucial role in distribution of the trace and rare earth elements in the studied ores. Consideration of the correlation coefficients among elements demonstrated that the neomorph phosphate minerals can be conceived as the potential host of rare earth elements.

The Ghoznavi coal mine, as an active mine in Golestan Provice, is located about 45km south of Azadshahr. Coal extracted from first (I) and third (Ш) coal layers. XRD and SEM/EDS studies indicate the presence of quartz and clay minerals as major and pyrite (arsenopyrite), gypsum, jarosite (natrojarosite), goethite, hematite, plagioclase, K-feldspar, rutile and corundum as minor minerals. After coal formation, jarosite, natrojarosite, hematite and goethite were formed due to the alteration of primeray iron-bearing minerals, such as pyrite. Berlinite, rutile, corundum, plagioclase and K-feldspar are not syngenetic minerals in the studied coal and they were transported from the outside to the sedimentary basin during precipitation of the organic materials. Presence of the quartz, plagioclase, K-feldspar, rutile and corundum seem to be generated from older igneous units such as Soltan Meydan basalts and alkaline granite in the Khoshyeilagh region, which are transfered to the lagoon. There are two generations of pyrite in the coal layers, including syngenetic euhedral pyrite, which is distributed throughout the coal matrix, and subhedral to anhedral pyrite as fissure filling. FT-IR study shows the presence of silicate and clay minerals, aromatic C=C stretching vibration related to the organic materials, and OH-bands related to the OH-bearing minerals.

The Siahrudbar bauxitic horizon is located in ~25 km southwest of Aliabad Katoul, Golestan Province, north of Iran. This deposit is stratiform and were developed along the boundary of the Elika and Shemshak formations. Petrographic observations along with the results of XRD analyses of the ore samples revealed that diaspore, hematite, and kaolinite are the major constituent minerals which are accompanied by lesser amounts of chamosite, anatase, boehmite, goethite, rutile, calcite, muscovite, clinochlore, and quartz. These minerals display various textures including pelitomorphic, granular, pseudo-porphyry, fluidal, pseudo-breccia, dumbbell-shaped grains, and clastic fragments, indicating allogenic origin. Based upon quantitative values of minerals, the Siahrudbar deposit consists of two types of ores, (1) the clayey bauxite and (2) the bauxitic clay. These ores were formed during deferrugenization and desilication processes from the clay minerals. The geochemical data of less mobile elements indicate that the Siahrudbar deposit is of karst bauxite type and generated from the weathering of igneous (basaltic-andesitic) rocks. Furthermore, the Eu anomaly values together with the ratios of TiO2/Al2O3 and Sm/Nd revealed that the Siahrudbar bauxitic deposit was formed in a continental margin tectonic setting.

The Shirinabad clay-bauxite deposit with more than 1 km long and about 8 m in thickness is located in 60 km south-east of Gorgan. The Shirinabad deposit has been developed as a stratiform horizon along the contact zone of Triassic dolomitic limestones and Jurassic shales and sandstones. The basal contact zone of the horizon is mainly undulatory¡ whereas the upper contact zone is concordant with the hanging-wall shales and sandstones. The rocks within the horizon show pelitomorphic¡ microgranular¡ oolitic and pisolitic textures. Textural analysis indicates both allochthonous and autochtonous origins for the Shirinabad deposit. Based on textural and mineralogical evidences the deposit can be divided into four distinct units. Kaolinite¡ anatase¡ routile¡ bohemite¡ hematite¡ goethite and berthierine are the principal constituents. From geochemical data¡ it is concluded that the Shirinabad deposit probably originated from basaltic volcanic rocks. Combination of mineralogical and geochemical data shows that the Shirinabad deposit formed in two stages. First¡ bauxite materials and clay minerals were developed as authigenic bauxitization processes of alkaline basaltic parent rock. Then¡ these materials were transported to karst depressions and formed the Shirinabad clay-bauxite deposit.

The Central Alborz in eastern Mazandaran province is host to the most important carbonate-hosted fluorite deposits in Iran, such as Pachi-Miana, Sheshroodbar, Era and Kamarposht. In these deposits, mineralization occurs in the upper parts of the middle Triassic Elika formation (Vahabzadeh et al., 2009 and references therein). These deposits have long been studied, and various models are presented for ore genesis. Nevertheless, ore genesis in these deposits is still unclear. The present study of the geochemistry of the REEs of these deposits is intended to improve genetic models.
Three hundred samples were taken from above mentioned deposits. Samples were categorized into 5 groups: (1) fluorite ore types, (2) ore-stage calcite, (3) carbonate host rocks, (4) basaltic rock around the deposits, and (5) shale of the Shemshak formation. Fourteen pure fluorite samples, 4 samples of pure calcite, 4 samples of carbonate host rock, 1 sample of basalt and 1 sample of shale were analyzed for REEs by ICP-MS at West Lab in Australia.
Analytical data on fluorite from the Elika deposits show very low REE concentrations (0.5-18ppm), in calcite(0.5-3ppm) in carbonate host rocks – limestone (1.8-7ppm), and in dolomitic limestone 6.5ppm, compared with upper Triassic basalt (43ppm) and shale (261ppm). REE in fluorite of these deposits are strongly enriched (10 3 to 10 6 times) relative to normal sea water, ore stage calcite and carbonate host rocks, especially for mid-REEs (Eu, Gd) and heavy REEs (Lu, Yb, La/Yb=~0.05).
Also, LREEs depletion (La/Sm= 2-10) and HREEs (La/Yb=0.01-0.08) relatively enrichment of fluorites compared with limestone (La/Sm=2.5-4, La/Yb=0.1-1.5) and dolomitic limestone (La/Sm=4.28, La/Yb=0.07-0.4) host rocks as well as positive Eu anomaly are the most important REEs signatures in fluorites.
Fluorite elsewhere in the world with low total REE conten thas been interpreted to have a sedimentary origin (Ronchi et al., 1993; Hill et al., 2000; Sasmaz et al., 2005). Strong enrichment of REEs in fluorite and carbonate host rocks worldwide, relative to normal sea water indicates that diagenetic and/or hydrothermal processes have contributed to the process. Depletion of LREEs and moderately strong HREE enrichment in fluorite relative to carbonate host rocks is interpreted to be post-sedimentation (Ronchi et al., 1993;Hill et al., 2000). Thisis supported by the hydrothermal character of the fluorite in the Elika deposits and similarity between REE profiles and those of fluorine-rich MVT deposits with hydrothermal origin (Chesley et al.,1994; Bau et al., 2003). Positive Eu anomalies in fluorite elsewhere suggest deposition reduced conditions and temperatures~250°C (Bau et al., 2003; Sverjensky, 1989). The present study indicates that low total REEcontents in fluorite precipitated from reduced hydrothermal solutions could be caused by (1) increasing pH of the ore-forming solution during interaction with carbonate host-rock, (2) gradually decreasing F concentration in hydrothermal solutions due to different generations of fluorite mineralization, and (3) low REE contents of carbonate hostrocks.

Portland cement could be produced by heating the raw materials (clay, limestone) about 1500°C which clinker will be formed. Geochemical and mineralogical studies of clinker, Portland cement, cement kiln dust and cement mill dust have been carried out by optical microscopy, X-ray diffraction and X-ray florescence. In phase system diagram (CaO-Al2O3-SiO2), chemical components of clinker cement occurred in C3S-C2S-C3A triangular. Clays play important in adsorption of trace elements and heavy metals in the raw materials of cement factory of Neka. According to Bogue equation, this clinker and Portland cement coincide with international standard of cement. Cement kiln dust could be reuse as raw material of cement factory. Mineralogical study of clinker indicates the presence of calcium silicates and brown millerit minerals, while calcium silicates (tricalcium silicate and dicalcium silicate), gypsum, larnit, brown millerit and calcite minerals are indentified in Portland cement. Mineralogical study of cement kiln dust indicates the presence of calcite, quartz, muscovite –illite and chlorite minerals, while calcium silicates (tricalcium silicate and dicalcium silicate), gypsum, larnit and brown millerit minerals are indentified in cement mill dust.

The Alborz structural zone in northern Iran is the host of a number of important coal deposits. The Gheshlagh coal mine is one of them, which is located 35 km southeast of Azadshahr. Coal bearing strata in the Gheshlagh mining district occur in the middle part of the Lower Jurassic Shemshak Formation which consists mainly of shales, siltstones and sandstones. The Geshlagh coals have a low sulfur content and a low ash yield. The ash content of coal and its geochemical character depends on the environment of deposition and subsequent geological history (Yazdi and Esmaeilnia, 2004). The purpose of this study was to investigate the texural and mineralogical characteristcs of the Ghashlagh coals and to identify the geochemistry of the major and trace elements and their relationship to specific mineralogical components. These results are necessary to improve the understanding of coal characterization and to relate the mineralogy of different materials to their potential for producing acidic or alkaline mine waters associated with mining and preparation processes. About 20 samples were collected from the main coal seams. These samples were taken from fresh faces of the mine to avoid weathered surfaces and get fresh samples. The petrography of the samples was carried out by the conventional microscopic methods at the Golestan University. Mineralogical analyses were done by a X-ray diffractometer equipped with a CuKα tube and monochrometer (XRD Philips PW 1800) at the Kansaran Binaloud Company. The coal samples were initially crushed to less than 200 µm and homogenized. Then, 50 g from each sample was heated to 525 oC according to the United States Geological Survey procedure (Bullock et al., 2002). The concentration of the major and trace elements in the resulting ash samples was determined using a wavelength X-ray fluorescence spectrometer (XRF Philips PW 1480) at the Kansaran Binaloud Company. The Coal-bearing formation in the Ghashlagh mine belongs to the clastic unit of the Shemshak Formation, consisting mainly of about 2400 m sandstone, siltstone, shale. The middle part of this formation includes the economic coal beds. Petrographic and mineralogical investigations indicate that the dominant mineral phases of the Gheshlagh coals are quartz, kaolinite, montmorillonite, albite, muscovite, illite and pyrite. Pyrite occurs as euhedral to anhedral crystals and locally as framboids which are disseminated in the coal. Oxidation products consist mainly of iron hydrosulfate resulting from the oxidation of pyrite. The organic/inorganic affinity of elements in coal was determined using the correlation coefficient between the elements and ash yeild. Si, Al, Ti, Fe, K, Na, Ga, Zr, Rb and Nb are mainly associated with minerals. Sr, Pb and Ni have a dual association. The concentrations of most trace elements in the Gheshlagh coal samples are high when compared with the usual reported range in the world. The contents of Pb and Ni show the highest concentrations. The Gheshlagh coals are characterized by relatively low amount of sulfur indicating deposition in lacustrine and swamp environments (Goodarzi et al., 2006). The concentration of Ni, V, Sr, Ba and Ce in the Gheshlagh coals are relatively higher than the Shahroud and Lushan coals (Yazdi and Esmaeilnia, 2004). The comparison of the concentration of trace elements in the Gheshlagh coals and worldwide concentrations (Swaine, 1990) indicates the enrichment of Ni and Pb in the Gheshlagh coals. Gluskoter et al. (1977) used a value of six times the Clarke value to determine if an element is enriched in the whole coal. By these criteria, the concentration of Ni and Pb are enriched in the Gheshlagh coals when compared with the Clarke values. Generally, the distribution and abundance of reacting mineral species in the coal mines can be used to predict the extent of acidification and neutralization in particular area. In the Gheshlagh coal mine, the frequency of pyrite is moderately low. In addition, the availability of carbonates in the host rocks provides buffering capacity for acid produced by oxidation in this area. This investigation has led to a better understanding of coals and their roof and floor lithologies in the Gheshlagh coal mine. Acknowledgment: The authors wish to thank the Iran Minerals Production and Supply Company (Project No. 30716) and the Department of Geology, Faculty of Sciences at the Golestan University for financial assistance and all necessary resources needed to carry out this research.

Tash and Astaneh bauxite deposits are located about 40 km north of Shahroud and 30 km northwest of Damghan, respectively. The Tash deposit has been developed as a stratiform horizon along the contact zone of Ruteh limestones and Elika dolomitic limestones, whereas the Astaneh deposit located along the contact zone of Triassic dolomitic limestones and Jurassic shales and sandstones. Pelitomorphic and microgranular textures are the most abundant matrix textural elements and ooids, pisoids and pellets are the main separated textural elements in these deposits. Textural analyses indicate both allochthonous and autochtonous origins for both deposits. Based on petrographic and facies evidences the Tash and Astaneh deposits can be divided into five and three distinct units, respectively. The Tash deposit is mainly composed of diaspore, anatase, kaolinite, hematite, goethite and berthierine, whereas the quartz, hematite, goethite kaolinite and anatas are the most abundant minerals in Astaneh. Combination of stratigraphic, petrographic and facies data show that Tash and Astaneh deposits formed in three and two main stages, respectively. First, bauxite materials and clay minerals were developed as authigenic bauxitization processes of the parent rock. During the second stage, these materials were transported to karst depressions, where they accumulated as a relatively thick bauxite horizon. Finally, during the third stage which has occurred only in Tash deposit, the ore upgraded by in situ leaching and desilicification. Based on geological, mineralogical and textural evidences both deposits can be grouped as karst bauxite type.

Portland cement could be produced by heating the raw materials (clay, lime stone) about 1500°C which clinker will be formed. The geochemistry and mineralogical studies of raw materials, clinker, Portland cement and dust have been carried out by optical microscopy, X-ray diffraction and X-ray florescence. The results of spectrometry indicate the presence of calcite mineral in limestone, montmorillonite, quartz, calcite, albite, muscovite, hornblende, orthoclase and chlorite minerals in clays, hematite minerals in ironstone, quartz, plagioclase, tourmaline minerals in siliceous materials and gypsum in gypsum rock. ‍‍‍Calcite is the main mineral and quartz, muscovite –illite and chlorite are the minor minerals in the dust of the furnace of the Neka cement factory. The mineralogical study of clinker indicates the presences of calcium silicates and brown millerit minerals, while gypsum, larnit, brown millerit and calcite minerals are indentified in Portland cement. calcium silicates (tricalcium silicate and dicalcium silicate), and larnit are the main minerals and Gypsum and brown millerite (tetracalcium aluminoferrit) are the minor minerals of the dust in the mill of the Neka cement factory. In phase system diagram (CaO-Al2O3-SiO2), chemical components limestone and clays occur in carbonate rocks and tridymite respectively, While clinker and Portland cement occurred in C3S-C2S-C3A triangular. According to Bogue equation, this clinker and Portland cement coincide with international standard of cement.

Present study is the first report of the rhenium and osmium isotopic data in the hypogene Cu-Fe sulfides (chalcopyrite and pyrite) from the Kerman porphyry copper deposits. Although data set was limited in this study, their interpretation helped to understand the possible sources of the metal for mineralization in the porphyry copper system. Based on this study, initial 187Os/188Os value in deposits recorded at least 0.1 to maximum 10 that the variation range for this ratio is much larger than the range detected in the Chilean porphyry copper deposit (from 0.15 to 5.2). The recorded non-radiogenic to radiogenic values for initial osmium ratio in primary sulfides of the Kerman porphyry copper deposits revealed isotopic heterogeneity and diversity in metal source for mineralization in these deposits. The record of the non-radiogenic values for initial 187Os/188Os (0.10- 0.15) in sulfides of the Miduk and Now Chun deposits, in the range of mantle values (0.13- 0.15), showed the main role of ore-forming fluids derived from mantle-derived magma (intrusive body) for supplying of the metal required for mineralization in these deposits. In contrast, too large deviation observed in initial 187Os/188Os values in sulfides of the Kerver (10) and Abdar (1) deposits respect to the mantle values showed the greater share of crustal sources (continental crust) rather than mantle sources in supplying of the metal for mineralization in these deposits. The Sar Cheshmeh deposit revealed less radiogenic value of initial osmium ratio in potassically sulfides (0.22) respect to phyllically sulfides (0.79), showing the contribution both the mantle and the crustal materials in supplying of the metal for mineralization, although the role of crust during the final stages of mineralization has been more important. The observed general trend in 187Os/188Os values being more radiogenic from old, high-grade deposits (middle Miocene) to young, low-grade deposits (upper Miocene- Pliocene) in the Kerman porphyry copper belt is attributed to increasing of the crustal sources contribution in generation of the young sub-productive-to-barren magmas and also in supplying of the metal for associated weak mineralization. This relationship can be suggested as a key for distinguishing and exploration of porphyry copper deposits with economic grades, the deposits that have been inherited greater share of the mantle source for generation of productive magma and also required metal for mineralization in porphyry system.

The Jajarm karst bauxite deposit is located about 175 km southwest of Bojnourd. The deposit has been developed as a stratiform horizon along the contact of Triassic dolomites and the Jurassic shales and sandstone. In this study، the textural elements of the Jajarm bauxites are classified into matrix and separated textures based on morphological and genetic criteria. Pelitomorphic and microgranular textures are the most abundant matrix textural elements and ooids، pisoids، pelletsand secondary occurrences are the main separated textural elements. Textural analyses indicated both allochthonous and autochtonous origins for the Jajarm bauxites. Detailed petrographic studies allowed the recognition of two types of ooids and pisoids based on morphological features and laminations. Type A is characterized by thin، regular and continuous lamination، whereas type B has thick، irregular and discontinuous lamination. Ooids and pisoids are mainly composed of alternating kaolinite-hemetite and diaspore-geothite laminae in which Al2O3 concentration increases towards the outer laminae. Fine-scale alternation of these laminae in the ooids and pisoids implies the climatic fluctuations of wet and dry seasons. Secondary textural elements are mainly observed as veins enriched in SiO2 and Al2O3.

The Motrabad epithermal system 30 km southwest of Bajestan is located in an assemblage of intermediate to silicic volcanic rocks. The mineralization occurs as irregular veins, veinlets and hydrothermal breccias. Hydrothermal alteration is developed around the veins and consists of silicic (

Eastern Alborz zone contains paleosols and bauxites that demonstrate paleoclimatic changes in addition to widely geological events in this zone. The Khoshyeilagh region is located about 50 km southeast of Azadshahr. Stratigraphic sequence in this region contains calcrete paleosols in Devonian sandstones of the Padeha Formation and a karst bauxite horizon along the contact zone of Permian limestones and Triassic dolomitic limestones. Textural and mineralogical evidences indicate the formation of paleosols in arid to semi-arid climate and the formation of bauxites in warm and humid climate. Also, range of weathering indices point out increasing of chemical weathering from Devonian paleosols to Permo-Triassic bauxites. Geochemical data combined with the geological evidences suggest that the basaltic rocks of the Soltanmeidan Formation are the parent rock of the studied paleosols and bauxites. Combination of textural, mineralogical and geochemical data show that paleosol formed in low temperature, low rate of precipitation, and low chemical weathering. In contrast, high temperature and high precipitation rate led to formation of chemical weathering during bauxites formation. Devonian paleosols of the Padeha formation and Permo-Triassic bauxites of the study area are good indicators for recognition of paleoclimatic conditions in this area.

The Tajroud vein system is located 190 km southwest of Mashhad، and in the southern part of the Sabzevar zone. The vein host rocks consist of Eocene intermediate to silicic volcanic rocks. The mineralization occurs as open space filling، taking place as veins، veinlets and hydrothermal breccias. Based on field geology and textural evidence، three main stages of mineralization were identified. Stage I mainly contains quartz، pyrite، chalcopyrite and magnetite. Stage II، which has the same mineral assemblage as stage I، is the most important stage in terms of volume. Finally، stage III is characterized by repetitive quartz and calcite banding with negligible amounts of sulfide minerals. Hydrothermal alteration is developed around the veins and tends to be more intense in the vicinity of the veins. The plot of the Ishikawa alteration index (AI) versus chlorite-carbonate-pyrite index (CCPI)، known as alteration box plot، displays three main alteration trends. The hydrothermal alteration assemblage of quartz، adularia، chlorite، illite، calcite، and epidote that envelops the Tajroud vein system formed from the upwelling of near-neutral to weakly alkaline hydrothermal solutions. The mineralogic، alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Tajroud vein system represents an epithermal system of low-sulfidation type.

The Alborz structural zone in northern Iran is the host of a number of bauxite deposits. The Gheshlagh bauxite deposit is one of them with more than 2 km long and a thickness of about 20 m in the eastern part of the Alborz structural zone. This deposit has been developed as a stratiform horizon along the contact zone of Permian limestones and Triassic dolomitic limestones. The basal contact zone of the bauxite horizon is mainly undulatory, whereas the upper contact zone is concordant with the hanging-wall dolomitic limestones. Based on mineralogical and textural evidences, the horizon can be divided from top to bottom into five distinct units: (1) upper bauxite unit with a thickness of about 5 m, is composed of boehmite, hematite, kaolinite, rutile and svanbergite, 2) upper kaolinite unit approximately 2-3 m thick and is composed mainly of clay minerals, 3) hard bauxite unit with a thickness of approximately 1.5 m, mainly consists of hematite, kaolinite, boehmite and diaspore, 4) lower kaolinite unit approximately 1-4 m thick and is composed of kaolinite, boehmite and diaspore, and 5) lower bauxite unit about 4-6 m thick. Textural analyses indicate both allochthonous and autochtonous origins for these deposits. Combination of geological, textural and mineralogical data of the Gheshlagh bauxite deposit correspond to a boehmitic-diasporic karst bauxite deposit type.   

Grade control and ore quality determination has always been considered a challenging task for geologists and mining engineers. Ore quality is dependent on various factors such as size and geometry of a deposit, geological disturbances, and texture and ore mineralogical composition. Determination of factors which control ore grade and prediction of a suitable area are very important in terms of economics and productivity of mining operations. This study has tried to develop spatial and statistical analyses for evaluating ore quality and recognition of ore grade influencing factors at Jajarm Bauxite Mine. Through incorporating topographic, geologic and geochemical data, the effects of faults, elevation and depth on the ore grade and module (wt% Al2O3/Wt% SiO2 ratio) has been assessed. The results showed that the amounts of Al2O3 and module increased as we get closer to the faults. Furthermore, there was not any effect of faults type and strike on grade and module. A negative correlation between both elevation and depth with the amounts of Al2O3 and module indicates ore quality improvement in lowlands and shallow depths. Thus, the combination of geographic information system (GIS) methods and multivariate statistical analyses might be more efficient in geo-spatial assessments.

Paleosols of the study area is a part of the Eastern-Alborz Zone which is located about 50 km southeast of Azadshahr. These paleosols developed on floodplain and lacustrine facies of the Devonian Padeha Formation. Based on the field and textural evidences, two major paleosol horizons identified as A and B horizons. The A horizon consists of calcrete and noncalcrete paleosols which is located in the floodplain facies of the Padeha Formation. The B horizon identified in the lacustrine facies and consists of calcrete paleosols. Quartz, calcite, dolomite, microcline, hematite, albite, sericite, illite, chlorite and montmorilonite were identified in the paleosols. Geochemical analyses of the paleosols reveal the enrichment of immobile elements and depletion of mobile elements. Investigations of chemical alteration and effective chemical alteration indices indicate intermediate weathering in the study area. The occurrences of noncalcrete and calcrete paleosols suggest a climate change from humid to dryer condition occurred during soil formation. Combinations of textural, mineralogical and geochemical data indicate an origin of basic igneous rocks for the paleosols of the study area.

In present study، Re concentration determined in 30 hexagonal (2H) and trigonal (3R) molybdenite samples belong to veinlets of different stages of hypogene mineralization from 7 porphyry Cu and Mo deposits from Kerman region. Re concentration in molybdenites of these ore deposits varied from 49 g/t to 1449 g/t which are in Re concentration range of other porphyry Cu and Mo deposits around the world. In general، 3R molybdenites show the higher Re concentration (average ~ 563 g/t) than those of 2H molybdenites (average ~ 479 g/t). Variations of Re concentration in molybdenite types deposited during different stages of hypogene mineralization indicate more concentration of Re in molybdenites precipitated with transitional (B-type veins) and late (D-type veins) stages of mineralization than those of early stage veinlets (A-type veins). This distribution suggest that Re with more acidic and cooler hydrothermal fluids at the transitional and the late stages of porphyry system evolution is more concentrated with silicification، sericitization، and argillization alterations. Present study indicated that molybdenites with high Re content are associated with porphyry copper deposits which are characterized by low average grade of Mo، limited contents of molybdenite، and also their productive intrusive is resulted from significant contribution of mantle-derived magmas respect to crustal materials. In addition to abovementioned signatures، frequency of 3R poly-type of molybdenite in ore deposits، less fractionated and more calcic composition of productive intrusive of ore deposits with their less radiogenic of Sr and Pb isotope ratios، as well as occurrence of late stages of acidic and low temperature hydrothermal alteration and mineralization processes in formation and evolution history of ore deposits are signatures of porphyry copper and molybdenum deposits with high Re contents.

The Galand-rud coal mine is one of the coal producing areas of central Alborz coal basin which is located in Mazandran Province. Based on mineralogical and geochemical studies pyrite is the main sulfide mineral in the mine. Based on correlation matrix, cluster analysis and principle component analysis (PCA), SiO2, Al2O3, Na2O, K2O and TiO2 are associated with alluminosilicate minerals, CaO, MgO and MnO with carbonate minerals (calcite and dolomite) and Fe2O3 and SO3 with pyrite. Ambiguous correlation between P2O5 and other major oxides and also the presence of apatite in Galand-rud coals indicate two sources for P2O5. A negative correlation between SiO2, Al2O3, Na2O, K2O, TiO2 and Cl indicate organic origin of Cl. Also, V and Rb originate from alluminosilicate minerals, Ni, Cu, Co, Cr, Pb, Ce, Y and Zn from sulfide minerals and Ba, Sr from carbonate and phosphate –bearing minerals. Galand-rud coals enriched in most of trace elements respect to China and America coals and Clark coals, whereas, exhaustion in Cl and Nb.

Wastewater can be used effectively in irrigation to provide some portion of the water required for agriculture purposes. But for using of the wastewater, the accurate monitoring on their quality should be done. In order to know the quality and suitability of waste water of coal cleaning factory of Vatani for irrigation purpose, the sampling from wastewater ponds and groundwater have been done during winter 2009. According to the hydrochemistry facies of Piper diagram, the wastewater and groundwater types in the studied area belongs to Ca-SO4 type and Ca-HCO3 type respectively. Sodium absorption ratio (SAR) (class S1), sodium percent (%Na), magnesium hazards and chloride potential are less than 10%, 60%, 50% and 20% respectively. The residual sodium carbonate (RSC) (1.25 meq/l) and kelly's ratio (1) for all the studied samples. Indicate that they meet acceptable quality for agricultural purposes. Wastewater studies are based on U.S. Laboratory's Salinity diagram, is in the range C3S1 in respect to ground water (C2S1) and shows high salinity. Wastewater studied samples on the Wilcox’s diagram lies in the area of permissible waters for irrigation. The Gibb's model shows that anions and cations of all the type of waters are of lithological origin. The positive chloroalkaline index of waters indicates that base-exchange reaction occurred between Na+ and K+ of the groundwater with Ca2+and Mg2+ of coal and coal tailings. The permeability index (PI) of all samples are permissible for irrigation.

The Argash antimony ore deposit is located at south of Neyshabour and the eastern part of the Sabzevar zone. This deposit occurs within a sequence of Eocene-Oligocene volcanic-intrusion rocks. The mineralization occurs as open space filling, taking place as irregular veins, veinlets and hydrothermal breccias. The mineralogy of the veins is comparatively simple. The primary antimony-bearing mineral is stibnite. Other sulfides have been found in association with stibnite are pyrite, chalcopyrite and sphalerite. Quartz, illite, adularia, chlorite, epidote and kaolinite are the main hydrothermalg gangue minerals occurring around the veins. Hydrothermal alteration is zoned around the veins and consists of three major types including silicification within the immediate veins, argillic alteration enveloping the veins, and propylitic alteration distal to the veins. The intensity of silicification and argillic alteration decreases with depth and away from the veins. The evaluation of the geochemical data set based on multivariate statistical analyses indicates positive correlation between Zn, Ag, As and Sb and the same distribution pattern of these elements in the boreholes. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Arghash quartz-antimony veins represent an epithermal system of the low-sulfidation type. This data suggests that boiling and cooling were the main ore deposition processes in the area.