Economic Geology
Maryam Khosravi; Wenchao Yu; Jintao Zhou
Abstract
The Gano bauxite deposit is located 90 km northeast of Semnan city in the eastern Alborz Mountains, northern Iran. The bauxite ores occur as stratiform discrete lenses with a length of 6 km and thickness of 2–20 m along the contact between carbonates of the Elika Formation and shale, sandstone, ...
Read More
The Gano bauxite deposit is located 90 km northeast of Semnan city in the eastern Alborz Mountains, northern Iran. The bauxite ores occur as stratiform discrete lenses with a length of 6 km and thickness of 2–20 m along the contact between carbonates of the Elika Formation and shale, sandstone, siltstone, and coal of the Shemshak Formation. Mineralogical analyses revealed that the bauxite ores consist of diaspore, hematite, kaolinite, chlorite, anatase, illite, zunyite, goethite, quartz, and dolomite minerals. Fluctuations of the groundwater table level, acidic atmospheric waters, and an increase in pH of the weathering solutions close to carbonate bedrocks played an important role in the concentration of Fe-poor ores in the upper parts and Fe-rich ores in the lower parts of the studied profile. An increase in oxidation, the possible presentence of secondary phosphate minerals, fluctuations of the groundwater table level, and the role of carbonate bedrock as an active buffer played an important role in the extent of Ce anomaly in the ores (0.79–12.25). The pH variations of weathering solutions, fluctuations of the groundwater table level, the role of carbonate bedrock as a geochemical barrier, and simultaneous precipitation of Fe-bearing minerals and preferential scavenging of LREE(La–Eu) by hematite played an important role in the distribution and fractionation of rare earth elements in the bauxite ores. According to geochemical considerations (Eu/Eu* vs. TiO2/Al2O3 and Sm/Nd bivariate diagrams), the Gano bauxite deposit probably derived from the weathering of intermediate igneous rocks.
Hasan Zamanian; Ghasem Beiranvand; Farhad Ahmadnejad
Abstract
Bagoushi deposit is located in 37 km northwestern Masiri in Fars province. Structurally the deposit is situated in the Zagros Simply Folded Mountain belt and developed in Upper Cretaceous carbonates. From the top to bottom, the deposit is consisting of red, pisolitic, brown, brecciate, and kaolinitic ...
Read More
Bagoushi deposit is located in 37 km northwestern Masiri in Fars province. Structurally the deposit is situated in the Zagros Simply Folded Mountain belt and developed in Upper Cretaceous carbonates. From the top to bottom, the deposit is consisting of red, pisolitic, brown, brecciate, and kaolinitic bauxite horizons. Boehmite, kaolinite, hematite, pyrophyllite, anatase, calcite and diaspore are the major mineral phases. The main ore textures of the deposit include pisolitic, pisolitic-oolitic and clastic with pelitomorphic and microgranular matrixes. According to the formation conditions of the major minerals, the Bagoushi deposit formed in an environment ranging from acidic-oxidizing surface water to basic and reducing groundwater. Some textural features such as pelitomorphic matrix, pisolitic and oolitic textures, radial fractures in pisoids, growth of simple cortex around earlier pisoids, pisoids with cortexes lacking radial and circular fractures, are indicative of allochthonous origin; and broken pisoids, allogeneic pisoids and clastic grains reveal the transportation of bauxitic materials; therefore the bauxite materials is authigenic, but in some parts were transported and re-deposited, at least locally. The mass change calculations relative to the immobile element Ti show that elements such as Si, Fe, Mg, K and Na are leached out; Al, Zr, V, Th, Nb, Ba and REEs particularly LREE are concentrated; and Hf, Ta, Co, Rb, Cs, Be and U are relatively immobile during the bauxitisation process. The bauxite ores are characterized by progressive enrichment of the REE compared to parent rock, intense LREE/HREE fractionation, relatively stable negative Eu anomalies, and weak negative Ce anomalies.
A Abedini; S Alipour; M Khosravi
Abstract
TheDarzi-Vali bauxite deposit is located in ~20 km east of Bukan, south of West-Azarbaidjan province (NW Iran). This deposit developed as stratiform layers and lenses within carbonate rocks of the Ruteh Formation (middle Permian). The mineralogical studies indicated that the surface waters with oxidizing-acidic ...
Read More
TheDarzi-Vali bauxite deposit is located in ~20 km east of Bukan, south of West-Azarbaidjan province (NW Iran). This deposit developed as stratiform layers and lenses within carbonate rocks of the Ruteh Formation (middle Permian). The mineralogical studies indicated that the surface waters with oxidizing-acidic nature and the underground waters with reducing-basic nature played an important role during the development and evolution of this deposit. Based on field evidences and geochemical studies, the basaltic rocks are the most probable parent rock of this deposit. Calculations of enrichment factor revealed that the elements of Si, Ca, Mg, Na, K, Mn, Co, Rb and Hf were leached during development of this deposit and the elements of Al, Ti, V, Th, Ga, Zr, Nb, U, and Cr were enriched. This is while the elements of Fe, P, Ni, Ba, and Y have borne leaching-fixation processes. The obtained data indicated that the factors such as adsorption, scavenging, residual concentrations, buffering of weathering solutions by carbonate bedrock, mineralogical control, differences in intense of alteration, organic matter, and fluctuation of underground water tables have played pronounced roles in distribution of major, minor, and trace elements in this deposit. This study also revealed that the Fe-poor and Fe-rich ores of this deposit have appropriate properties for being used in refractory and cement industries, respectively.
O. Gerayloo; S. H. Hosseini; J. Sarghaini; R. Salimi
Abstract
Jajarm bauxite mine as a largest known bauxite ore reserves with more than twenty million tons of diasporic bauxite, located in the north of Khorasan province, Iran. This bauxite mine cannot provide the suitable feed for at least twenty tears. Therefore, the possibility of using other bauxite deposits ...
Read More
Jajarm bauxite mine as a largest known bauxite ore reserves with more than twenty million tons of diasporic bauxite, located in the north of Khorasan province, Iran. This bauxite mine cannot provide the suitable feed for at least twenty tears. Therefore, the possibility of using other bauxite deposits such as Shah-Bolaghi bauxite mine in Tehran province and Sorkh-cheshmeh mine in the north of Khorasan province was investigated. These studies were carried out based on the dissolution and sedimentation velocity of red mud. The results show that using these deposits separately is not applicable, because of low dissolution and/or low sedimentation velocity of red mud. The other parameters such as dissolution temperature, the amount of lime and Na2Oc must be carefully controlled to have the better results. Accordingly, a mixture of 50-50 Jajarm and Shah-Bolaghi bauxite ore has had the better performance with higher dissolution efficiency and also the lesser alumina amount in red mud.
F. Ehya; M. Lotfi
Abstract
The Sarfaryab bauxite deposits occur in karstic depressions at the top of the limestones of the Cenomanian to Lower Turonian Sarvak Formation, which are overlain by the limestones of the Santonian Ilam Formation. In order to determine the possible source rocks of the Sarfaryab bauxite deposits, a few ...
Read More
The Sarfaryab bauxite deposits occur in karstic depressions at the top of the limestones of the Cenomanian to Lower Turonian Sarvak Formation, which are overlain by the limestones of the Santonian Ilam Formation. In order to determine the possible source rocks of the Sarfaryab bauxite deposits, a few samples were collected from Sarvak Formation, terra rossa and bauxite ore and geochemically and geostatistically analyzed. Plots of chemical data and correlation coefficients show that Al, Ti, Zr, Nb, Cr and V were immobile during the bauxitization process. In the scatter diagrams of Zr and TiO2 versus Al2O3, regression lines pass through the origin and terra rossa falls between the Sarvak Formation and bauxite. Based on this research, it can be stated that the source rock of the Sarfaryab bauxite deposits is the Sarvak Formation and terra rossa is an intermediate product during limestone-bauxite transformation. Post-Turonian uplift had exposed recently deposited limestones of the Sarvak Formation to karst weathering, and a layer of argillaceous debris accumulated on its surface and was partly converted to bauxite. Subsidence followed, and the bauxite was preserved by the deposition of limestones of the Ilam Formation. Uplift in Pliocene time, with ensuing erosion, exposed the bauxite deposits to their present situation.
A. Zarasvandi; H. Zamanian; E. Hejazi; A.H. Mansour
Abstract
The Sar-Faryab bauxite deposit is located in 250 km east of Ahvaz city in Kohgeloye and Bovair-Ahmad Province, Iran. Structurally the deposit is located in the Zagros Simply Fold Mountain Belt and was formed between the Ilam and Sarvak Formations. The bauxite horizon in this deposit consists of ...
Read More
The Sar-Faryab bauxite deposit is located in 250 km east of Ahvaz city in Kohgeloye and Bovair-Ahmad Province, Iran. Structurally the deposit is located in the Zagros Simply Fold Mountain Belt and was formed between the Ilam and Sarvak Formations. The bauxite horizon in this deposit consists of marly limestone, argillite, oolitic-Pisolitic, yellow, red and white bauxite. This study uses the geochemistry of immobile elements (Al, Ti, Zr and Y) to trace the precursor rock of the bauxite deposit and to calculate the mass changes that took place during weathering and bauxitization. The result indicates that elements are depleted and elements are enriched during the weathering and bauxitization. Geochemical data show that argillaceous debris in the Sarvak limestone can be the source of the Sar-Faryab bauxite deposit.
D. Esmaeily; A. Esna Ashari; H. Rahimpour Bonab
Abstract
Study of source rock materials in Jajarm bauxite deposit is the main subject of this study to show its origin. From bottom to top, this deposit consists of lower argillaceous layer, argillaceous bauxite, hard bauxite and upper kaolinite units. Correlation coefficients and scatter ...
Read More
Study of source rock materials in Jajarm bauxite deposit is the main subject of this study to show its origin. From bottom to top, this deposit consists of lower argillaceous layer, argillaceous bauxite, hard bauxite and upper kaolinite units. Correlation coefficients and scatter diagrams of immobile elements in these four layers, demonstrate an early homogenous origin at the beginning of the bauxite formation. Accordingly, source materials were separated slowly due to the different conditions dominated in different parts of the deposit. Difference in drainage conditions and leaching of some elements from upper part and their re-deposition in lower parts of the deposit are the main reasons for hard bauxite separation from argillaceous one. Formation of the lower argillaceous layer, located between argillaceous bauxite and carbonate footwall is due to the direct contact of the argillaceous bauxite and carbonate footwall and also difference in drainage rate in contact area of the two layers. Geochemical evidence also depicts that upper kaolinite formation is the result of the silica leaching from upper horizons and its re-deposition in hard bauxites. Compositional comparison of studied samples with chondrite and upper continental crust demonstrates the effect of both of the basic and sedimentary rocks in evolution of the Jajarm bauxite. Formation of this deposit can be considered as a result of the alteration of the primitive laterite in an area close to the current location of the deposit. During alteration and transportation bauxite is deposited on the karstic topography and then some continental sediment was added to it.
N. KhajehMohammadlo; E. Rasa; A. Emamalipur
Abstract
Alibaltalo bauxite deposit is situated in east Shahindezh, south west of west- Azarbaijan. This ore horizon lies along the boundary between Jurassic sandstone and Triassic dolomtite. In this study for understanding the chemical process involved in the formation of the bauxite deposite and in order ...
Read More
Alibaltalo bauxite deposit is situated in east Shahindezh, south west of west- Azarbaijan. This ore horizon lies along the boundary between Jurassic sandstone and Triassic dolomtite. In this study for understanding the chemical process involved in the formation of the bauxite deposite and in order to determine the role and behavior of elements on weathering process, the gain and loss and mass transfer methods, enrichment -depletion diagrams were used. the result of this study diabase sills of Doroud Formation in the area is proposed as the principal source of this bauxitic horizon.. Mass change calculations for different elements compared to an immobile element (Titanium)- with. chemical stability in weathering processes. Results showed Si, Na, K, Mg, Ca depletion while Fe, Al, Ti showed secondary enrichment.The ore body shows decreasing in total mass of -21.02 for brown horizon,-21.02 for gray kaolinite layer,-22.91 for green to gray part and -23.55 for green to gray color horizon.