Iron Ore Exploration Research Articles

Assessment of the Environmental and Socio-economic Impacts of Iron Ore Exploration Activities in Uganda. A Case Study of Iron Ore Mines in Muko Sub-County in Rubanda District

This study assessed the environmental and socio-economic impacts of iron ore exploration activities in Uganda, specifically focusing on iron ore mines in Muko Sub-County, Rubanda District. The research has three specific objectives. First, it seeks to identify the various iron ore exploration activities being carried out in the study area. Second, it aims to uncover the challenges faced by the local communities living around the iron ore site. Lastly, the study aims to examine the interventions that have been implemented to address these challenges. Various data collection tools like interviewing, observation, focus group discussion, and questionnaires were applied to gather the required data for this study. By conducting a comprehensive analysis of the environmental and socio-economic impacts, this research hopes to contribute to a better understanding of the potential consequences of iron ore exploration activities. It also seeks to provide valuable insights into the strategies that can be employed to mitigate these challenges and foster sustainable development in the region. The findings of this study indicated that various exploration and exploitative iron ore activities have been carried out within the study area such as; open-pit mining, site preparation, hauling and transportation, survey, and mapping among others. The study also revealed that; conflicts, displacements of residents from their lands, degradation of the environment, and employment opportunities among other effects have arisen. On the issue of measures to mitigate the effects, EIAs, and restorations of the degraded environment were identified. This study concluded that; the results of this study show that the study region has been significantly impacted by iron ore exploration and extraction activities. Environmental degradation brought on by these practices includes soil erosion, water contamination, and deforestation. In addition, socioeconomic developments such as eviction, loss of livelihoods, and growing inequality have affected the nearby villages. In conclusion, both the environment and the nearby communities have suffered as a result of iron ore exploration and exploitation activities in the study region. To lessen these negative effects and encourage sustainable practices in the sector, immediate action must be taken.It was also recommended that strict laws and enforcement by government agencies and community engagement should be put at the fingers point to ensure the most sustainable iron ore mining not only in the study area but also in the country-Uganda as a whole. Keyword: Environmental impacts; Socio-economic impacts; Iron ore exploration; Uganda; Muko Sub-County

Automated geological logging from FTIR reflectance spectra utilising geochemical and historical logging constraints

In iron ore exploration, mineral samples are obtained from a drill hole and their compositions logged as proportions of material types, which encapsulate mineralogical and textural attributes. This logging is used to inform the properties, i.e. mineralogical, grade, and handling, of the orebody during mining and processing. Logging has historically been recorded manually, and as such is subjective and time consuming.We have developed a system that uses objective datasets, namely Fourier Transform Infrared reflectance spectra, geochemical assays, and a priori geological constraints, within a machine learning system to objectively log these mineral samples. The system is trained on samples logged by expert geologists in a laboratory environment. The resultant objective logging optimally satisfies constraints including matching the theoretical chemistry (calculated from the logging) to the laboratory assays, and satisfying the sample’s known geological context.We present comparisons of the logged material type proportions recorded by expert geologists in a laboratory environment with the proportions produced by the objective logging system, and also against geologists’ field logging proportions of the same samples. These comparisons demonstrated that the objective logging system’s proportions closely matched the geochemically validated expert-logged proportions for important individual material types, and over larger mineralogical groupings, and groups of material types of different textural hardness. Additionally, the system outperformed field logging, relative to laboratory-based logging, according to r2 and RMSE metrics. These results demonstrate an improvement over geologists’ field logging, while removing the subjectivity inherent in the human logging process.

Analysis of the mechanical behavior of an alternative sand for foundry molding

The exploration and beneficiation of iron ore result in a substantial generation of waste, predominantly directed towards tailings dams, heightening environmental concerns. Faced with this environmental challenge, numerous studies have been devoted to seeking sustainable solutions, aiming at the utilization of waste in various sectors of the economy. In this context, this study focuses on the technical feasibility investigation of using sandy iron ore waste as molding sand in foundry processes. Foundry molding sand, crucial in casting, must meet specific requirements and exhibit particular characteristics to effectively fulfill its function. To address this issue, test specimens were fabricated using three distinct types of sands: Standard Sand, Sand 01 (without magnetic separation), and Sand 02 (subjected to magnetic separation), combined with two binders (bentonite and sodium silicate). Subsequently, the test specimens underwent mechanical tests for tension, flexure, and compression, with the aim of evaluating their ability to withstand applied forces. The results of these tests revealed that Sand 02, when combined with sodium silicate, demonstrated satisfactory performance, in accordance with established standards and studies for obtaining sands intended for molding in foundry processes.

Performance of Ore Sand as Aggregate for Interlocking Blocks

The search for alternatives that can replace conventional materials extracted from nature is crucial for environmental sustainability. This is especially the case for construction and geotechnical engineering, as this sector is a major consumer of the planet’s natural resources. This paper explores the use of ore sand (OS) tailings with fine aggregate characteristics, which are generated during exploration of iron ore and usually stored in stacks, in terms of their potential for replacing conventional aggregates (gravel, natural sand, and limestone sand) used in interlocking paving blocks for light-traffic pavement. A comparative life cycle assessment (LCA, cradle-to-gate) approach was applied for aggregates in interlocking blocks produced using OS compared to blocks produced with conventional aggregates. The OS was able to replace 24wt% of conventional aggregates (100% limestone sand and 13.3% natural sand), while maintaining compressive-strength performance similar to that of the conventional block (35 MPa). For all eleven environmental-impact categories evaluated in the LCA, the block with OS has improved environmental performance compared to the conventional block. Through the creation and use of a scoring indicator (SI), it was possible to determine that the transport distance of the OS is a limiting factor for the environmental efficiency of the alternative block. Nonetheless, the incorporation of OS mitigates the impacts of block production on eutrophication, acidification, fresh water, human toxicity, and abiotic depletion. The use of tailings reduces the demand for natural resources, decreasing the environmental impact of production and promoting sustainable construction practices.

BIF-hosted high-grade magnetite iron ore targeting by hyperspectral wavelength mapping of chlorite: case study of Qidashan Iron Mine, northeast China

There are two kinds of chlorites occurred in Anshan area, among which the hydrothermal Fe-chlorite with longer Fe-OH wavelength is spatially related to the high-grade magnetite ore, meaning that wavelength mapping of chlorites can be used to target the BIF-hosted high grade iron ore. In this article, quadratic polynomial, cubic spline, and quartic polynomial method were used to interpolate the absorption wavelength near 2250 nm of China ZY1-02D satellite hyperspectral image. The result of quadratic polynomial is continuous without data overlapping or intervals, thus most suitable for discrimination of the chlorites. The field truth shows that the spatial distribution of Fe-chlorite, validated by XRD analysis, is not only in accordance with that of high grade magnetite ore bodies, but also consistent with the recently discovered concealed iron bonanza. The study shows that hyperspectral remote sensing techniques can play significant role in the exploration of magnetite iron ore in east Liaoning Province.

Detection of iron-bearing mineral assemblages in Nainarmalai granulite region, south India, based on satellite image processing and geochemical anomalies.

Although India's large iron ore reserves are well known, there are still few studies and research on iron ore prospecting in smaller deposits or the deposits with lower grade. Remote sensing concepts are useful to target for mineral exploration, since it covers a large area at low cost. In this research spectral remote sensing and digital image processing of ASTER data to locate and delineate the regions with iron oxide-bearing soils in granulite terrain at Nainnarmalai (southern India) that has hypothetical reserve 8.2 million tons of iron in sub-surface banded magnetite quartzites. The image-based study component involved pre-processing atmospheric correction and processing of the image data reminiscent of band ratio and band mixture to locate iron-bearing soils. We used blending of bands 5/3 + 1/2 to delineate ferrous iron oxide, band combination of 2/1 to delineate ferric iron oxide, and band ratio of 5/4 to delineate the lateritic soil. Further, the linear spectral unmixing outcome of ASRER data was evaluated concerning the ground truth of geochemical compositions of samples from the study area. Our results showed that image processing of the ASTER satellite data has the potential to delineate ferric, ferrous, and lateritic mineral assemblages in the iron-bearing soils with minimal requirement of ground truth verification. This research work aided in increasing trust in the use of space-based data for mineral prospecting. Image processing has demonstrated that ASTER data can be used to enhance iron ore exploration and the discovery of new mineralized areas.

Obituary: R.H.Sawkar (1935 –2022)

An eminent Geologist, Shri R.H.Sawkar breathed his last peacefully on the morning of June 1,2022 at the age of 87 in his home at Bengaluru. Shri R.H. Sawkar is survived by his Wife, Son, Daughter and Grand-Children and their families are settled in Bengaluru. Born on March 29, 1935 to Hem Reddy Sawkar and Lingamma Hiregoudar, he is from Magala Village, Huvinhadagalli taluk, Vijayanagar dist, Karnataka. He had four brothers and two sisters. He graduated with B.Sc. (Hons) in Geology in 1959 and M.Sc. in Geology in 1961 from Mysore University followed by Diploma in Aerial Photo Interpretation and training in I.T.C (Australia)-Mineral Exploration and Mine Development Programme under Colombo Plan. He was sportsman, swimmer and wrestler. Started his career in Dept of Mines and Geology, Govt of Karnataka as Assistant Geologist in1959. During 1959 -1964, he was associated for the exploration of Iron ore of West Coast, Clay & Feldspar deposits in Goribidanur taluk, mineral resources of South Canara, Limestone deposits in Bijapur and Belgaum, Gold deposits of Gadag Gold Fields, Karnataka. From 1964-1966 as Geologist (Jr.) he was deputed to National Mineral Development Corporation Ltd (NMDC), here he was associated with the exploration of Iron ore deposits of Kudremukh area, for the preparation of the detailed project report for Visvesvaraya Iron and Steel Ltd for mining iron ore. During 1966 -1970, he was associated the Dharwad division inspection of mining leases, exploration of Iron, Manganese ores of North Canara,Bauxite deposits of coastal area, site selection of Vijayanagar steel Plant, Karnataka. From 1970 - 1976, on deputation, he was associated with the Mysore Minerals Ltd (Karnataka State Minerals Corporation Ltd) as Project Manager and Agent for ore production, sales, shipment, transportation, mine planning, exploration of various minerals, etc. During 1976-1985, on deputation, he worked as Project Manager of Karnataka Copper Consortium Ltd. for the exploration and mine development of Kalyadi Copper Project, Ingaldhal Copper Mine, assisted the Karnataka State Govt in the merger proposal of these copper companies with the Hutti Gold Mines Co Ltd (HGML), merger took place with HGML on 12.07.1985. From1985 -1995, he worked in different capacities in HGML for the Chitrdurga Copper Unit, Gadag Gold Project and Corporate Planning etc. After Retiring from HGML on 31.3.1995 as Executive Director, he worked in HGML as Technical Advisor up to 1.6.1997. He was associated with all the leading earth science associations in India and abroad. Currently, he was Secretary General of the Geological Society of India and actively associated with the MEAI, Rashtriya Jal Biradari, Water Development Rural and Urban societies, Dam Safety etc. He was a member of various State and Central Govt committees. He has presented and published several papers in the national and international seminars and also chaired the technical sessions. He was actively involved as advisor/consultant to the exploration, mining and metallurgy industries. He travelled widely, a simple man with tons of curiosity to discover new things. He guided and inspired the many. Shri R.H. Sawkar will remain in the hearts of the many. He will be missed deeply by his family and colleagues.

PENGATURAN DAN PENJAMINAN INVESTASI PADA KAWASAN PESISIR DAN PULAU PULAU KECIL DI PROVINSI SULAWESI UTARA

This study aims to analyze the regulation and guarantee in the implementation ofinvestment in coastal areas and small islands by local governments as well as how tosupervise and control investment activities in coastal areas and small islands as well as theauthority of the Regional Government to stop and revoke the investment permit. Thenormative legal research method is used to examine in depth the regulation and guaranteeof the Regional Government in the implementation of investment in the coastal area ofNorth Sulawesi. In order to obtain data in this study, data collection techniques are neededto obtain primary data and secondary data, both of which will be analyzed. The datacollection technique used in this research is literature study. The result of the research showsthat the local government is still not optimal in the court of investment activities in theCoastal area of North Sulawesi. As a result of this, investment cases arise. The famous casesof investment in the Coastal Area are the Buyat Bay case or the coastal area pollution caseby PT Newmont Minahasa Raya, the iron ore exploration case on the North Minahasa islandof Bangka by PT MMP whose case went to the Supreme Court with the Supreme Courtdecision Number 255 of 2016 which won the community and revoke PT MMP's activities onthe island of Bangka. But until now the company has carried out its activities and thecommunity continues to struggle. The third case is PT MSM which, although it has beenrejected and dismissed by the North Sulawesi DPRD in 2016 but is still operating until nowIn investment activities in coastal areas, from these cases, the government tends to neglectand does not take action to stop the company's activities.
 Keywords: Arrangement, guarantee, investment, coastal, small islands, North Sulawesi.

Iron Ore Exploration In India: A Personal Perspective

Iron Ore Exploration In India: A Personal Perspective

Petrology of Precambrian metagranites and heavy mineral chemistry of the Olounou area within the Cameroon mineral belt (Ntem complex, South Cameroon): relationships with the Fe mineralization

The petrology of Achaean biotite- and amphibole-rich metagranites, the geochemistry of Fe occurrences and heavy mineral concentrations in stream sediments from Olounou (Ntem complex) help to constrain their inter-relationships. These metagranites display granoblastic textures outlined by microcline, biotite, amphibole and oxides. Ilmenite (60 to 80%), zircon (15 to 20%) and rutile (1 to 2%) are the mineral fractions in pan concentrates. Two types of Fe mineralization as silicified veins cross-cut the above rocks: hematite ± magnetite quartzites with primary hematite enclosing magnetite relicts contain high average Fe 2 O 3 (69.05 wt%) and TiO 2 (0.73 wt%); banded magnetite-rich quartzites with magnetite partially replaced by hematite are characterized by Fe 2 O 3 (52.15 wt%), TiO 2 (0.27 wt%), relatively high W (286 ppm) and Ni (108 ppm). Both types have Zn, Cu, Ga contents below 10 ppm, positive Eu anomalies, HREE enrichment over LREEs and low ΣREE (9.76 to 12.07). Iron and SiO 2 were derived from weathering of Archean biotite and amphibole metagranites, deposited in existing Post-Archean intracratonic basins under greenschist facies and impacted by submarine hydrothermal solutions. These results are genetically comparable to other Precambrian BIFs and underline the iron potential of Olounou. They equally contribute to iron ore exploration in Cameroon and worldwide. Supplementary material : Table S1 is available at https://doi.org/10.6084/m9.figshare.c.5426547

The Laboratory-Based HySpex Features of Chlorite as the Exploration Tool for High-Grade Iron Ore in Anshan-Benxi Area, Liaoning Province, Northeast China

Anshan-Benxi area in Liaoning province is an important banded iron formations (BIFs) ore-mining district in China. Chlorite is widely distributed in this area, which is related to BIFs and high-grade iron ore, respectively. A fast and convenient method to identify the type and spatial distribution of different chlorites is crucial to the evaluation of high-grade iron ore in this area. Qidashan iron mine is a typical BIFs deposit, and its BIFs-related high-grade iron ore reserves are the second largest in the area. In this paper, the laboratory-based HySpex-320m hyperspectral imaging was used to study the wall rock in Qidashan iron mine. A hyperspectral imaging processing model was established for mineral identification, mineralogy mapping, and chlorite spectral features extraction. The results show that the wavelength positions of OH, Fe-OH, and Mg-OH absorptions of chlorite in the altered wall rock of high-grade iron ore are between 1400 and 1410, 2260 and 2265, and 2360 and 2370 nm, respectively, which are longer than those around BIFs. The relationship between cations in the octahedral layer of chlorite and the wavelengths of OH, Fe-OH, and Mg-OH indicates that Mg and Mg/(Mg + Fe) are inversely related to these wavelengths, whereas Fe is positively related. The wavelengths appear to be weakly influenced by AlVI. Since the bandpass of hyperspectral imaging systems is usually less than 10 nm, these chlorite wavelength differences can be used as a favorable tool for the high-grade iron ore exploration and the iron resources evaluation in the Anshan-Benxi area.

Machine learning assisted geological interpretation of drillhole data: Examples from the Pilbara Region, Western Australia

In minerals exploration, routine drilling is performed and the data logged from these drillholes, including lithological composition, assays, and downhole geophysical measurements such as natural gamma logs, are used to create geological interpretations of the strata within each drillhole. A 3D geological model can be created by identifying corresponding stratigraphic boundaries within multiple drillholes. These models can be used for understanding the formation and the mineral endowment of a deposit.We introduce a system for producing stratigraphic interpretations of iron ore exploration drillholes in the Pilbara region in Western Australia. The algorithm firstly classifies each data modality independently for each geological interval, for example 2 m, with classification results for each stratigraphic unit as output. These classifiers, for geological logging, assays, gamma logs, were trained on historical datasets over a wide range of strata in the Pilbara. The influence of each classifier can be adjusted according to the user’s preference, and a novel optimisation algorithm incorporates known geological features such as dykes, faults and thicknesses of various stratigraphic units, to objectively create the best fit interpretation of the geology. A geologist can then adjust this interpretation to include local knowledge.Manual interpretations of 396 drillholes from a high-grade iron ore deposit are compared to interpretations of the same hole prepared by the algorithm. Analysis of interval-by-interval interpretations, and basement geology demonstrate that without any human input, similar interpretations are produced while reducing manual effort.

Domestic peculiarities of financing and organizing geological research of iron ores

The mineral base of iron ores is characterized by intensive use and includes explored and pre-explored reserves, most of which belong to a distributed subsurface fund. The objects of accounting (deposits) are grouped according to the size of stocks and on the basis of involvement in industrial development. The allocated groups of deposits, for which the volumes of reserves are set, make up 100 million tons, 100–500 million tons, 500–1000 million tons. and more than 1000 million tons. The grouping of reserves of iron ore deposits by size allows us to state that about 80 % of the reserves of iron ores for the developed deposits are provided with reserves of 500 million tons. and more, which confirms the average level of their exhaustion. The degree of provision of iron ore reserves according to the existing special permits for the use of subsoil and project output for production was introduced. Groups of fields for which the terms are set are up to 30 years, 30–50 years, 50–100 years and over 100 years. It has been determined that financing of exploration works (GAR) for iron ores in the framework of the current National Program for the Development of the Mineral Base of Ukraine until 2030 is provided exclusively at state cost and non-state funding is not taken into account. In order to identify the optimal distribution of financing for exploration works by stages, comparison of funding rates under the Program up to 2030 with the distribution of the main geological risks and general risks of mining business has been made. At the stage of search and search-and-appraisal, a high level of geological risks of 50 % and mining risks in 70 % is accompanied by public funding for iron ore and reaches a critical value of 80 % with a similar indicator for the entire program at 65,7 %. The level of financing of the III stage of exploration for iron ore accounts for 20 % of the total volume, with a rather low level of geological risks of 10 % and mining risks at 10 %, respectively.

Geology of the Gouap iron deposit, Congo craton, southern Cameroon: Implications for iron ore exploration

The Ntem Complex represents the northwestern edge of the Archean Congo craton in southern Cameroon where numerous banded iron formation (BIF)-hosted iron deposits have been discovered. The Gouap iron deposit, which is located on the western edge of the Ntem Complex, is one of the recent discoveries of iron deposits in this area. In this study, geological mapping, detailed drillcore logging and petrographical studies reveal that the Gouap iron deposit comprises of two lithostratigraphic units, namely the BIF and the Country rocks. The BIF unit consists of amphibole BIF and amphibole-pyrite BIF, whereas the Country rocks unit is made up of gneisses (garnet, amphibole–magnetite and amphibole–garnet–pyrite gneiss), schists (amphibole–magnetite and garnet–magnetite micaschist), quartzites and dolerite sills.The BIFs are well interlayered and observed to be in sharp or gradational contacts to their associated country rocks. The mineral assemblages of the BIFs and wallrocks (except the dolerites) indicate that both units have been metamorphosed under amphibole facies conditions. Two main iron mineralization types are identified in the Gouap deposit: the soft iron type which is mainly located in the western and northern parts and the hard iron type mostly confined to the southern sector of the deposit.The structural controls of the Gouap iron deposit are better observed in drillcore samples other than on the outcrop-scale. There are three principal deformation events (D1, D2 and D3) that led to the development of foliation, folding and faulting respectively. The iron mineralization are mostly concentrated on the F2 fold hinge zones and fractures that acted as passage ways for the circulation of meteoric water at surface. We suggest that the following three major processes that led to the formation of the Gouap deposit: (i) the chemical precipitation of chert and iron-oxide followed by sedimentation and diagenesis that formed chert–magnetite BIFs; (ii) secondly, the amphibolite facies metamorphism and deformation that formed quartz–magnetite BIFs, which constitute the main iron ridge located on thicker zones of fold noses; and (iii) finally, the Gouap BIFs have been upgraded to medium-grade iron ore due to supergene enrichment processes, which are restricted to the modern land surface and locally reached deeper levels through fault and fracture zones. The western and northern parts of the Gouap deposit have been identified as potential exploration target areas for iron mineralization. Even though the iron formation processes of the Gouap deposit are not yet completely understood and many questions remain unanswered regarding the genesis of the soft and hard iron mineralization, these new insights have important implications on the exploration drilling strategies of this deposit.

Persistence of rare species depends on rare events: demography, fire response and phenology of two plant species endemic to a semiarid Banded Iron Formation range

The association of rare plant species and Banded Iron Formation (BIF) ranges in semiarid Western Australia is a noted phenomenon. These ranges are also a focus of iron ore exploration and mining. Decisions and planning required for development, conservation and management resulting from this interest, often consider translocation of these threatened species. Nonetheless, little is known about the ecology of BIF-endemic species to support any such decisions. We assessed population structure, patterns of growth, mortality, recruitment, reproduction and in situ seedbank persistence for two declared rare flora species. The shrub Darwinia masonii, and sedge Lepidosperma gibsonii are endemic to an area <40 km2 on the south-western boundary of the Australian arid zone. Both species were found to be long lived and slow growing, with evidence for reliance on rare events such as fire, and high rainfall years, including, for some processes, consecutive high rainfall years for growth, reproduction and recruitment. Retrieval and germination of seed batches shows that both species’ seedbanks are long-lived, with seasonal dormancy cycling. This, together with the ability of mature plants to survive through years not supporting growth, and, for L. gibsonii, to resprout after fire, are key mechanism for persistence in this unpredictable and low rainfall environment.

Iron ore prospecting based on very low frequency-electromagnetic and geoelectrical resistivity at Wadi Abu Subeira, Northeastern Aswan, South Egypt

The serious need and high demand of iron oxides in cement industry urges to carry out critical investigation in vicinity of cement factories in South Egypt Governorates. The considered area Wadi Abu Subeira lies to the north east of Aswan. The possible occurrences of hematite in the subsurface enforced to carry out some geophysical measurements in the in the form of very low frequency-electromagnetic and geoelectrical resistivity.A total number of 684 very low frequency-electromagnetic and 54 vertical electrical soundings stations were executed along 9 surveying profiles arranged on three long traverses, running from west to east direction. The data sets were comprehensively and steadily inverted/transformed in terms of subsurface electric resistivity/EM-equivalent current-density. Both the vertical and lateral resistivity/current-density variations were able to image the typical shallow stratigraphic sequence of the area. The present study emphasized the robustness and cost-efficiency of applying the very low frequency-electromagnetic and geoelectrical resistivity techniques in a field like iron ore exploration.

A Data Mining Approach to Validating Drill Hole Logging Data in Pilbara Iron Ore Exploration

A Data Mining Approach to Validating Drill Hole Logging Data in Pilbara Iron Ore Exploration

Exploration for iron ore in Agbado-Okudu, Kogi State, Nigeria

This report details the result of geophysical exploration for iron ore; which involved vertical magnetic intensity (∆Z) and gravity measurements, to delineate the geometry and depth extent of the deposit and acquiring quantitative and qualitative information for pre-drilling purposes in Agbado-Okudu. It is located about 3 km from Jakura along Lokoja-Jakura marble quarry and within low latitude precambrian basement complex district of Kogi State, Nigeria. A total of 517 magnetic measurement points along 16 traverses and 330 gravity reading along 11 profiles on the deposit in northeast–southwest azimuth were undertaken. The magnetic and gravity data enhancement involved linear regression curve fitting and fast Fourier transform, which were used to construct residual magnetic (RM) and gravity (RG) anomalies, analytic signal amplitude, Euler deconvolution at varying spectral indices (SI), power spectrum, and source parameter image (SPI), using the submenu of Geosoft Oasis Montaj software. Interpretation of the RM and RG anomalies revealed a primary causative body which perfectly correlates the positive anomalies and iron ore deposit, in form of a horizontal or gently dipping dyke with strike length of 600 m and average width of 110–130 m, within the gneiss complex in the north and trending south of the area. A secondary causative body associated with the negative anomalies and inferred as a vertical/near vertical thin sheet striking northeast–southwest coincided with the granitic and quartzitic intrusion. The NW–SE and E–W lineament trend conformed Kibarian and Liberian orogeny cycles of generally known structural trends in Nigeria, which shows that the iron ore deposit is structurally controlled. Depths to sources were estimated within range ≤ 2–24 m and 37.5–60 m, regarded as shallow and relatively deep depths, respectively. Ten vertical boreholes ranging in depth between 50 and 100 m are recommended, five of which require a priority attention to ascertain the thickness of the primary causative body.

Chemical Degradation and Processes of Erosion of Post-Mine Territories After Mining Exploration of Iron Ore

Chemical Degradation and Processes of Erosion of Post-Mine Territories After Mining Exploration of Iron Ore

Detecting and mapping different types of iron mineralization in Sangan mining region, NE Iran, using satellite image and airborne geophysical data

The Sangan mining region is the largest Fe skarn in western Asia has emplaced into the Khaf-Kashmar-Bardaskan volcano-plutonic belt in the NE Iran. In this region, carbonate rocks of Jurassic skarnified and hosted different epigenetic types of iron minerals, including magnetite, hematite, goethite, and limonite. The combination of remote sensing and airborne geophysical data is a powerful tool for mapping and interpreting iron mineralization in some area with intensely rugged topography or a broad expanse area, where systematic sampling and conventional geological mapping has some limitation and time consuming. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite data and airborne geophysical magnetometry data were used for evaluating and mapping different types of iron mineralization in the Sangan mining region. Preprocessing of the datasets involved band ratio (BR), principal component analysis (PCA), spectral angle mapper (SAM), and constrained energy minimization (CEM) of the visible-near infrared and short wave infrared ASTER data were used to map four types of iron minerals (magnetite, hematite, goethite, and limonite). For preparing a lithological mapp of this region, an RGB image produced by combination of BR and PCA, (R:(5+7)/6, G:PC3, B:PC 5). Implementing SAM and CEM technique were useful for mapping and detecting magnetite, hematite, goethite, and limonite. The Reduce To the Pole (RTP) map of the airborne geophysical magnetometry data is a practical tool for iron ore exploration that were used in this region for enhancing high anomalous signature of magnetite after extracting granitoid rocks. The integration of the extracted information from the ASTER image processing algorithms and geophysical magnetometry, mapped iron mineralization and identified new potential of high magnetite mineralization. The results verified by geological map and comprehensive fieldwork. This integration model can generalize to other arid and semi-arid regions with iron potential for both regional and district scales.