Role of REMOTE SENSING applications in MINERAL exploration and sustainable development in OMAN Rajendran Sankaran* and Sobhi Nasir** * Department of Earth Sciences, Sultan Qaboos University, Oman ** Earth Science Research Centre, Sultan Qaboos University, Oman. E-mail: [email protected] Spectra of minerals: Remote Sensing capability to map minerals • Hyperspectral images can be analyzed in ways that multispectral images cannot ASTER spectral bands Absorptions Figure Shows the spectral absorptions of major minerals rocks stacked from the USGS Spectral Library for minerals (Rajendran and Nasir, 2015). Economic Mineral Resources of the Sultanate of Oman (Ministry of Commerce and Industry, Oman. 2012). Fig. 1. Minerals occurrence map of the Sultanate of Oman Significance: Satellite data and Mapping of minerals of the Sultanate of Oman • Applications of remotely sensed satellite data are wide and unique in mapping of different lithologies, mineral resources and ore deposits. • Oman has potential occurrence of the industrial minerals and ore deposits which are mostly occurred in inaccessible mountains and deserts regions where it is difficult to do conventional geological mapping. • The technique is low-cost and save time in mapping and exploration of such resources and well suitable and applicable to Oman and arid region. Spectral bands Absorption characters of ASTER and Image processing Methods • This work shows t he absorption characters of spectral bands of Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) and • Selected imaging processing methods namely decorrelation stretching, band ratios, linear spectral unmixing (LSU) and Mixture Tuned Matched Filtering (MTMF) • To understand the sensor has capability to map several mineral deposits and different rock lithologies in Oman • It includes copper, chromite, awaruite, and manganese deposits, and limestone, listwaenites, carbonatites, metamorphic zones rock formations of different parts of the Sultanate of Oman. CASE STUY 1: ASTER detection of chromite bearing mineralized zones in Semail Ophiolite Massifs of the northern Oman mountain Rajendran et al. (2012) Ore geology reviews, 44, 121-135. d. N a. b. 56º15' 56º25' N AL Shinas LEGEND Mq-Maqoum formation Dh- Dhera formation Wadi Fizz Hf- Halfa formation Gulf of Oman Ex- Oman exotics * HD-Hamrat Duru group of * formations * * Wa-Wahrah formations E- Basic extrusive mostly ** 24º * 24 spilites with pillow lava or 35' * * * * º * conglomerate * 35' * * Hasaifi D- Diabase dyke swarms * * * * n G- Gabbro * HG-Gabbroid hypabyssal rocks * PG-Cumulate layered gabbro * P - Sheared* Cr serpentinized * harzburgite with minor dunite * * Wadi Fizz * * * * * * 24º * 24 Geology of Oman Mountain (after 25' * º Scale: 0 5Km 25' Watts, 1990) showing the locations of b. Al Hinaynah Ophiolite Sequence, c. geology (Source: * Ministry of Petroleum and Minerals, * Ro’s Sultan Sohar 1987) and d. ASTER RGB (3,2,1) image of study area 56º15' 56º25' c. P D PG G D E P G E Landsat TM RGB (7, 5, 4 PG E bands) decorrelated image G of Study area (Abrams et P al., 1988). The E abbreviations of the image are E- Basic extrusives D CD D mostly spilites with pillow lava or conglomerate; D- D Diabase dyke swarms; G- D E Gabbro; HG- Gabbroid PG hypabyssal rocks; PG- P Cumulate layered gabbro; P HG and CD- Sheared CD serpentinized harzburgite. D E HG PG P CD D E CD PG P HG E E P PG a D b D . P G . P G P D P D G E G E G G P P E E G E G E P P P P G E G E D D D D C P C P D D D D E E P D P D P G P G HG HG C D E C D E D D P P G G C P C D E P D E D C D C P HG D HG P D G P P G E E E E P P C P C P D G D G c. D P G P D ASTER RGB band ratios image a. G E G Abdeen et al., 2001 (4/7, 4/1, P E 2/3*4/3) b. (4/7, 3/4, 2/1) and c. G E Amer et al., 2009 ((2+4)/3, P P G E (5+7)/6, (7+9)/8) of the study D D area. The abbreviations of the P D image are E- Basic extrusives P D E mostly spilites with pillow lava or P G conglomerate; D- Diabase dyke HG D E swarms; G- Gabbro; HG- P Gabbroid hypabyssal rocks; PG- G Cumulate layered gabbro; P and P D E CD- Sheared serpentinized P P HG G harzburgite. E E P P G P D PG G D E P G E PG E G RGB image of PC7, PC5 and PC4 of PCA bands of the P study area. The abbreviations E of the image are E- Basic D extrusives mostly spilites with CD D pillow lava or conglomerate; D- Diabase dyke swarms; G- D Gabbro; HG- Gabbroid D E hypabyssal rocks; PG- PG Cumulate layered gabbro; P P and CD- Sheared HG serpentinized harzburgite. CD D E HG PG P CD D E CD PG P HG E E P PG CASE STUY 2: Characterization of ASTER spectral bands for mapping of alteration zones of volcanogenic massive sulphide deposits Rajendran and Nasir (2017) reviewed paper submitted to Ore geology reviews. Geology of study area shows the occurrence of Cu, Au and Ag mainly in the lower extrusive (Ministry of Petroleum and Minerals, 1987) RGB image of ASTER band ratios (5/3+1/2), (4+6)/5 and (5+7)/6 shows the mineralized zones (spotted Cu occurrences) of the study area (Image is linear stretched with Red: 1.1 to 1.3; Green: 3.6 to 4.3; Blue: 1.8 to 2.0). RGB image of ASTER indices (R: OH bearing altered minerals, G: kaolinite B: alunite minerals indices) shows the occurrence and spatial distribution of altered minerals in the study area (Red square is an area chosen for detailed study; the image is linear stretched with Red: 2.5 to 3.1; Green: 1.6 to 2.0; Blue: 1.0 to 1.4). (a) ASTER RGB (3, 2, 1) image shows the occurrence of gossan (yellow squared, the area in Fig. 16) and old mine, and (b) the distribution of pixels of the oxidised (red), propylitic (green), argillaceous (cyan) and phyllic (pink) zones derived based on SAM endmembers (1, 3, 5 and 7) over MNF image (band 2) of the gossanized area. CASE STUY 3: Mapping of manganese potential lithology in parts of the Sultanate of Oman Rajendran and Nasir (2017) International Journal of Geosciences and Geomatics 1(2), 92-101. 5935’E 5940’E 5945’E Ese Jgw N EOsa Geology of study region occurred near Ras Al Hadd of Al- Batain basin of NE Qcy-z Oman margin 2225’N 2225’N (Ministry of Petroleum and Minerals 1993). Qed 2230’N 2220’N Qes Qby -z 5935’E 5940’E 0 4km 5945’E Rhodochrosite HS338.3B Manganite HS 138.3B Pyrolusite O-6A Psilomelane HS 139.3B Spectral plot of manganese minerals stacked Image spectra of 14 ASTER spectral bands from USGS and JPL spectral libraries. shows diagnostic absorption of manganese in VNIR and SWIR regions (1-9 spectral bands, low Pyrolusite (MnO2), Psilomelane ((Ba, H2O)2 reflectance) and strong emission in TIR region Mn5O10), Manganite (MnO(OH)) and (10-14 spectral bands). Rhodochrosite (MnCO3) Ese Ese JKwac Sea water Qty Qcy-z Qty LEGEND EOsa Qcy-z Qty intrusions JKwac Qty JKwac Qty Qby-z Jgw Qcy-z JKwac Post –Nappe Units Jgw Qcy-z Jgw Quaternary Formations Jgw Jgw Qty Qfy Qty -Sub-recent alluvial fans and terraces Qcy-z Qty Jgw Qtx Qty Jmb2 c JKwa Qtx c -Ancient alluvial terraces JKwa c Qty Qtx JKwa Qty TRsm - Sabkhah deposits Qty Jgw TRsm Qby-z c Mn c JKwa Qty Jgw JKwa Qty Qtx - Slope colluviums and collapse structure JKwac Qcy-z c JKwa Jgw c Qty Qtx JKwa - Aeolian sand veneer Qty Qes Qty Jgw Qtx -Low active sand dunes, meso-ridges Qed Qty c c Jgw JKwa Qtx JKwa Qty Qty JKwac Tertiary Formations c Qcy-z c JKwa c - Dhofar Group: Shama Formation JKwa JKwa Qtx Bioclastic marl limestone, bioclastic Qty EOsa limestone and dolomite Qty TRsm c - Upper Hadhramaut Group: Seeb JKwa c Qty Qty JKwa JKwac Ese Formation- Bioclastic limestone, c JKwa b calcarenite and marl subordinate sandstone PTRaj Qtx Qty Qty Qtx Hawasina Nappes Qty JKwac TRsm Qty Qty Al Aridh Group: Sayfam Formations TRsm JKwac - Megabreccia, calcirudite, radiolarian chert, micritic Qty JKwac TRsm v limestone with pelagic bivalves. Qtx TRsm JKwac - Basaltic andesite Qty JKwac Qty Hamrat Duru Group JKwac TRsmv c Wahrah Formation: JKwac c JKwa JKwa - Red and white Radiolarian chert, shale, calcarenite JKwac c Qty JKwa Qty JKwac JKwac Guwayza Formation: TRsm Jgw TRsm Jgw - Oolitic calcarenite, calcirudite TRsm JKwac JKwac Qty TRsm Qtx c b Matbat Formations: JKwa PTRaj - Turbiditic quartz sandstone, calcarenite, shale. Jmb2 Qtx Qty - Radiolarian chert, calcarenite, micritic Qfy Qty Qby-z Jgw limestone with pelagic bivalves TRmb1 Qfy v Qed Qfy Paj TRsm P b Jgw TRaj Qes Al Jil Formations: Qtx - Calcirudite and Permian carbonate as boulders and b Qes PTRaj megabreccia Qfy - Basaltic pillow lava, andesite Qty v Paj TRmb1 c Qty Qtx JKwa Qfy Mn (Manganese) Arrows area zoomed Qfy Qfy Qfy ASTER RGB image of band ratio (1+3)/2, (3+5)/4 and (5+7)6 of study region. Ese Ese JKwac Sea water Qty Qcy-z Qty LEGEND EOsa Qcy-z Qty intrusions JKwac Qty JKwac Qty Qby-z Jgw Qcy-z JKwac Post –Nappe Units Jgw Qcy-z Jgw Quaternary Formations Jgw Jgw Qty Qfy Qty Qcy-z Qty -Sub-recent alluvial fans and terraces Jgw Qtx Qty Jmb c 2 JKwa Qtx c -Ancient alluvial terraces JKwa c Qty Qtx JKwa Qty TRsm - Sabkhah deposits Qty Jgw TRsm Qby-z c Mn c JKwa Qty Jgw JKwa Qty Qtx - Slope colluviums and collapse structure JKwac Qcy-z c Jgw Qtx JKwa c Qty JKwa - Aeolian sand veneer Qty Qes Qtx Qty Jgw -Low active sand dunes, meso-ridges Qty c c Qed Jgw JKwa Qtx JKwa Qty Qty JKwac Tertiary Formations Qcy-z c JKwac JKwa c JKwa - Dhofar Group: Shama Formation Qtx Bioclastic marl limestone, bioclastic Qty EOsa limestone and dolomite TRsm Qty c JKwa c - Upper Hadhramaut Group: Seeb Qty Qty JKwa JKwac Ese Formation- Bioclastic limestone, c b JKwa PTRaj calcarenite and marl subordinate sandstone Qtx Qty Qty Qtx Hawasina Nappes Qty JKwac TRsm Qty Qty Al Aridh Group: Sayfam Formations TRsm JKwac - Megabreccia, calcirudite, radiolarian chert, micritic Qty JKwac TRsm v limestone with pelagic bivalves.