JOURNAL OF ECONOMIC GEOLOGY
Year:2015 | Volume:7 | Issue:1|Papers Count:10

Introduction:The Shahrestanak Mn deposit is located in southern Qom province, 12 km southwest of the city of Kahak. Based on geological-structural divisions of Iran, the deposit belongs to central volcanic belt or Urumieh-Dokhtar zone. The Venarch deposit is one the most important known manganese deposits in Iran. The Sharestanak and Venarch deposits are spatially and temporally related to each other, and have similar geology, mineral texture and structure, host rocks, relationships with faults, and depositional environment. So, their magmatism and deposition conditions can be related to each other. Since no systematic study on the Shahrestanak deposit had been performed before discussing its geological and geochemical characteristics, here it is being attempted to study the geology, petrography, geochemistry of major, minor and trace elements, and Rare Earth Elements (REE) of ore, to distinguish the depositional environments and genesis of this deposit and to compare REE of ore in this deposit with other deposits.

Introduction:The Ferezneh prospect area is one of the eastern anomalies of Khaf’s Sangan iron mine. The Sangan mines complex is located within the Khaf-Kashmar-Bardeskan volcano-plutonic and metallogenic belt in northeastern Iran.The Sangan mine is the largest Fe skarn in western Asia, having a proven reserve of over 1000 Mt iron ore@53% Fe (Golmohammadi et al., 2015) and consisting of three parts; western, central and eastern Sangan, each part including several anomalies. In this study, Ferezneh (North and West) prospect area which is an eastern anomaly of the Sangan iron ore is discussed. Ferezneh anomaly is located in 60o36'7"-60o34'27"E and 34o30'47"-34o29'46"N, 35 km south of the city of Taybad, 10 km southeast of Karat and 1.5 km southwest of Ferezneh village. The purpose of this study was to prepare a geologic map for separation and identification of the intrusions, determining their relationships with mineralization, distinguishing the type of mineralization, mineralogy, petrology and geochemistry of the mineral deposits, and finally their relationship with other major Sangan’s deposits.

Introduction:Heavy metals are the most toxic pollutants in aquatic ecosystems. This contamination can result from the release of heavy metal elements during alteration and weathering of ultramafic and mafic rocks (ophiolite zones). Among the important metals and pollutants in the ophiolite; chromium, cobalt, nickel, iron, magnesium, manganese, zinc and copper could be noted. Basically, a mass of serpentine consists of serpentine, amphibole, talc, chlorite, magnetite, and the remainder of olivine, pyroxene and spinel (Kil et al., 2010). In such areas, the prevailing cold climate, during the serpentinization, chloritization and epidotiization, the activity of the solvent, such as chloride, fluoride, carbonates, sulfide, sulfosalt would be able to import the elements such as magnesium and iron, copper and zinc into the soil and groundwater. The study area is located in northwestern Iran. This area is located in the northwest of the city of Khoy.Because of the proximity to the north and northwest Khoy plains with ophiolite rocks, the soil of this region could possibly show the potential of contamination with heavy metals. Due to the toxicity and disease of unauthorized grades of these elements in groundwater in the study area, this study is focused on the more contaminated groundwater of the areas.

Introduction:Several valuable calcite deposits are located in Ghare-Gheshlagh, south basin of Urmia Lake, NW Iran. Ghare-Gheshlagh area is situated in the northern part of tectono-sedimentary unit, forming NW part of Tertiary Sanandaj-Sirjan geological belt (Stocklin and Nabavi, 1972). The predominant rock types of the area include light color limestones (Qom Formation) and Quaternary alluviums and underlined dolomite in depth (Eftekharnejhad, 1973). The thickness of these units varies between 10 cm and 6 meters and up to some hundred meters in length.In the present study, the effect of geochemical parameters responsible for precipitating calcite from the carbonate aqueous fluids is interpreted by the TOPSIS method to find the most preferable sampling sites and geochemical data.

Introduction:The study area is located in central part of the Khaf-Kashmar-Bardeskan belt which is volcano-plutonic belt at the north of the Dorouneh fault in the north of Lut block. The north of the Lut block is affected by tectonic rotation and subduction processes which occur in the east of Iran (Tirrul et al., 1983). The magmatism of Lut block begins in Jurassic and continues in Tertiary (Aghanabati, 1995). Karimpour (Karimpour, 2006) pointed out the Khaf-Kashmar-Bardeskan belt has significant potential for IOCG type mineralization such as Kuh-e-Zar, Tannurjeh, and Sangan (Karimpour, 2006; Mazloumi, 2009). The data gathered on the I-type intrusive rocks include their field geology, petrography, U–Pb zircon dating and Sr–Nd isotope and also alteration and mineralization in the study area.

Introduction:Hornblende-bearing gabbroic rocks are quite common in subduction-related magmatic suites and considered to represent magmatic differentiation process in arc magmas (Heliker, 1995; Hickey-Vargas et al., 1995; Mandal and Ray, 2012). The presence of hornblende as an important mineral phase in gabbroic rocks of subduction zone has been considered either as an early crystallizing mineral from water-bearing mafic magmas (Beard and Borgia 1989; Mandal and Ray, 2012) or as a product of reaction of early crystallized minerals (olivine, pyroxene and plagioclase) and water-rich evolved melt/aqueous fluid (Costa et al., 2002; Mandal and Ray, 2012). The careful study of petrology and geochemistry of hornblende-bearing gabbroic rocks from Chahak area, of Neoproterozoic age, can provide important information about their petrogenesis. Because of the special characteristics of Chahak hornblende gabbros according to their age and their situation in the main structural units of Iran, their study can present critical keys for the knowledge of geological history of Iran specially central Iran zone.

Introduction:Mesgar iron occurrence is located in northwestern part of the Central Iran, 115 km south of Zanjan. Although there is a sequence of volcanic-pyroclastic rocks accompanied by iron mineralization, no detailed works had been conducted in the area. The present paper provides an overview of the geological framework, the mineralization characteristics, and the results of geochemical study of the Mesgar iron occurrence with an application to the ore genesis. Identification of these characteristics can be used as a model for exploration of this type of iron mineralization in the Central Iran and elsewhere.

Introduction:Pyrite oxidation and acid mine drainage (AMD) are the serious environmental problems associated with the mining activities in sulphide ores. The rate of pyrite oxidation is governed by the availability of oxygen (Borden, 2003). Therefore, the identifying oxygen supplying mechanism is one of the most important issues related to the environmental assessment of waste rock dumps (Cathles and Apps, 1975; Jaynes et al., 1984; Davis and Ritchie, 1986). Although comprehensive researches were performed on the mathematical description of oxygen transport processes using the numerical modeling (Morin et al., 1988; Blowes et al., 1991; Wunderly et al., 1986; Elberling et al., 1994; Jannesar Malakooti et al., 2014), so far, the interactions between these processes and geochemical and mineralogical characteristics has not been studied especially in waste rock dumps. Therefore the main objective of this study is to identify the evidences for knowing the oxygen transport mechanisms in the waste dumps and also, its role in intensity of pyrite oxidation. It is expected that such these structural studies could be useful for better understanding of dominant processes in numerical modeling and also providing environmental management strategies in the study area and other sites by similar characteristics.

Introduction:One of the first principles in the formation of a reserve is mineralogical, construction and mineral textures studies and investigation of paragenetic relations in the ore minerals. In addition, to petrographic studies, isotopic investigates have wide applications in economic geology. In general, copper isotope variability in primary (high temperature) mineralization forms a tight cluster, in contrast to secondary mineralization, which has a much larger isotope range. A distinct pattern of heavier copper isotope signatures is evident in supergene samples, and a lighter signature characterizes the leached cap and oxidation-zone minerals. This relationship has been used to understand oxidation–reduction processes (Hoefs, 2009). Also for a better understanding of the origin of the Jian Cu deposit, this research focuses on the origin and composition of the fluid and elucidation of its evolution during the mineralization process. In order to achieve this end, field observations, vein petrography, microthermometry of fluid inclusions and stable isotope analyses of veins and minerals were investigated. The present study also compares high and low temperature sulfide samples in an attempt to document and explain diagnostic d65Cu ranges in minerals from the Jian deposit.

Introduction:Mineral composition of source rock is one of the most important factors for concentration and distribution of heavy metals in sediments. Therefore, study on distribution of these elements and the related minerals in sediments provides information about natural origin of elements. Moreover, the interpretation of origin and distribution of sandy sediments is considerably enhanced by mineralogical and geochemical studies of these sediments.The main objective of this research is to evaluate distribution of Zn, Cu, Sr, Cd, Fe and Mn in sand sediments of the Oman Sea, their relationship with mineral composition of the sediments and also determining their provenance.