Article

Remote sensing techniques using Landsat ETM+ applied to the detection of iron ore deposits in Western Africa

Arabian Journal of Geosciences (Impact Factor: 1.22). 11/2013; DOI: 10.1007/s12517-012-0725-0

ABSTRACT

Remote sensing methods enable the rapid and inexpensive mapping of surface geological and mineralogical features. This capability proves highly useful when working on isolated or inaccessible areas. In this study, several enhancements of Landsat Enhanced Thematic Mapper plus (i.e. band ratios, false colour composites and principal component analysis) were used and evaluated to obtain the best possible visualisation of iron deposits hosted in the Devonian sedimentary rocks of northwestern Africa. In particular, two test sites were chosen: southern Algeria (Djebilet area), where the literature mineralogical and geological data on iron mine fields were already available, and the Western Sahara (the southern flank of Tindouf Basin), which was investigated during a field campaign and was where the occurrence of an analogous sedimentary succession led us to hypothesise the possible presence of exploitable iron deposits. This work demonstrates the usefulness of multispectral imagery in the detection of iron-rich areas and establishes a full remote sensing procedure, which can be profitably applied to a wider region of Western Sahara and can provide interesting perspectives on the possibility of detecting new exploitable iron ore deposits in arid environments.

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Available from: Andrea Ciampalini, Dec 13, 2013
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    • "During the last decades, Remote Sensing proved to be a useful means for assisting mineral/ore exploration by using a variety of satellite imagery, as a number of publications can manifest (Chica-Olmo et al. 2002; Tangestani & Moore 2002; Abbaszadeh & Hezarkhani 2013; Brandmeier et al. 2013; Ciampalini et al. 2013; Sadeghi et al. 2013; Salem et al. 2013; Magendran & Sanjeevi 2014; Pournamdari & Hashim 2014; Zadeh et al. 2014). In this study, a Very High-Resolution (VHR) satellite image (Worldview-2) is used in order to automatically distinguish those minerals that are hosts for gold mineralization, as well as to delineate lineaments (potential faults) which enable the transportation of hydrothermal fluids, thus producing the ore mineralization. "
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    ABSTRACT: The study area is located near the town of Filippoi, north of the city of Kavala in Northern Greece, known from ancient times for its rich gold mines, situated inside hydrothermal alteration zones (Fe-Mn oxide minerals). A Very High Resolution/VHR (0.5 m pixel size) image of Worldview-2 satellite was digitally enhanced, yielding target areas of potential ore existence and lineaments. Ground-truth that followed digital image processing, revealed abandoned ancient mines, slags and ore occurrences. Also, a number of lineaments delineated on the satellite image were verified as faults.
    Full-text · Article · Jan 2016 · Geocarto International
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    • "The usage of remote sensing to separate mineralization and alteration zones has become the initial approach for mineral prospecting in recent years (Ferrari 1992; Kenea 1996, 1997; Yamaguchi et al. 1998; Crosta et al. 2003; Ramadan and Kontny 2004; Galvão et al. 2005; Ninomiya and Cudahy 2005; Al Rawashdeh et al. 2006; Mars and Rowan 2006; Moghtaderi et al. 2007; Gad and Kusky 2007; Elsayed Zeinelabdein and Albiely 2008; Dogan 2008, 2009; Madani 2009; Shalaby et al. 2010; Amer et al. 2010; Azizi et al. 2010; Dehnavi et al. 2010; Beiranvandpour and Hashim 2011, 2012a, b; Rajendran et al. 2012; Sadeghi et al. 2013; Salem et al. 2013; Ciampalini et al. 2013; Rahimzadegan et al. 2014). Recognition of distribution of ore deposits and their relation to special alterations, survey of mining waste extensions , and regional structure and trending of mineral deposits are among the benefits of remote sensing methods in mineral exploration. "
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    ABSTRACT: The aim of this research is discrimination of the hydrothermal alterations related to copper mineralization in the Daralu deposit, which is located in the south of Kerman, SE Iran. The rocks of the surrounding area consist of Eocene volcanics and Oligocene–Miocene intrusive bodies. The main mineralization has occurred in a granodiorite porphyry intrusion and to some extent in the nearby volcanic and pyroclastic rocks. Some methods such as band ratio, principal component analysis (PCA), and supervised classification methods like spectral angle mapper (SAM), spectral feature fitting (SFF), and linear spectral unmixing (LSU) were carried out on Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Enhanced Thematic Mapper Plus (ETM+) satellite images in order to detect propylitic, phyllic, and argillic alterations. In addition, potassic alteration was studied by LSU using region of interest (ROI) method for resampling on the basis of the field studies. LSU procedure displayed the best matching with the reality in comparison with the field observations at the Daralu deposit. Two major fault systems with NW-SE and NE-SW trends were determined by remote sensing using linear enhance and sharpen filter by visible near-infrared (VNIR) in ASTER bands. Propylitic, argillic, and phyllic alterations show the same directions with the major faults of the area.
    Full-text · Article · Dec 2015 · Arabian Journal of Geosciences
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    • "Further geological information was inferred through correlation with the same sedimentary sequence cropping out in the south of Algeria (Djebilet), where three iron districts are present (Guerrak 1988). Then, a photo-lithological mapping of Western Sahara, based on enhancement of Landsat ETM+ imagery, was used to define the extent of the sedimentary unit, cropping out in Algeria and Western Sahara, which hosts the Algerian iron deposits near Djebilet (Ciampalini et al. 2012b). "
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    ABSTRACT: At present, Western Sahara is politically one of the most sensitive areas of the World. Its economic development could be achieved through the exploitation of mineral resources that can be found in the almost unexplored area administrated by the Saharawi Arab Democratic Republic. In this paper, we describe applications of known and cost-effective remote sensing techniques to detect and map areas containing mineral deposits, through the enhancement of Landsat ETM+ imageries. Several image processing techniques (false color composite, band ratioing, and principal component analysis) were used to highlight the presence of iron deposits. Two test areas were selected, one in Western Sahara and another one in Algeria. The occurrence of iron deposits in these test areas was assured using literature data for the Algerian test site and through a field campaign for the Western Sahara. There is good agreement between the ground truth data and the results obtained by the enhancements of the satellite images. Landsat images can be downloaded free of charge and their enhancements does not need expensive hardware or software tools. Therefore this technology could be transferred to the Saharawi technicians, enabling them to explore and manage the mineral resources of their own country independently.
    Full-text · Article · May 2013 · Natural Resources Research
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