Related by context. All words. (Click for frequent words.) 75 airborne EM 73 VTEM geophysical 72 geophysical conductors 72 UTEM 71 airborne electromagnetic 71 gravity geophysical surveys 71 coincident geophysical 71 airborne radiometric 71 electro magnetic EM 71 airborne electromagnetic EM 71 airborne geophysical anomalies 70 Detailed mapping 70 Geological mapping 70 induced polarization surveys 70 lithogeochemical 70 InfiniTEM survey 70 Horizontal Loop Electromagnetic 70 airborne magnetic anomalies 70 electromagnetic surveying 70 geophysical conductor 70 graphitic horizons 70 VTEM airborne survey 70 CSAMT 70 surface geochemical anomalies 70 electromagnetic anomalies 70 induced polarization IP 69 induced polarization geophysical surveys 69 IP geophysics 69 induced polarization survey 69 HLEM 69 EM conductors 69 DEEPEM 69 Geophysical surveys 69 Megatem 69 magnetic geophysical anomaly 69 anomalism 69 MMI soil geochemical 69 electromagnetic surveys 68 IP geophysical surveys 68 REE bearing 68 scintillometer survey 68 VTEM anomaly 68 EM conductor 68 gold copper porphyry 68 electromagnetic geophysical survey 68 electromagnetic conductors 68 soil geochemical survey 68 VTEM surveys 68 MegaTEM 68 BHEM 68 induced polarization 68 EM anomalies 68 anomalous geochemical 68 VTEM airborne 68 IP geophysical anomalies 68 conductive anomalies 68 petrographic studies 68 dipole dipole IP 68 anomalies coincident 68 airborne VTEM 68 ZTEM survey 68 mineralized outcrops 68 EM geophysical survey 67 magnetite mineralization 67 airborne magnetic survey 67 VTEM anomalies 67 geochemical geophysical 67 Induced polarization 67 geological mapping trenching 67 airborne electro magnetic 67 coincident magnetic 67 enzyme leach 67 anomalous radon 67 airborne EM survey 67 airborne geophysical 67 magnetic electromagnetic 67 EM geophysical surveys 67 airborne radiometric survey 67 borehole geophysical 67 CSAMT surveys 67 VTEM survey 67 airborne magnetic 67 ZTEM 67 Au Cu mineralization 67 conductive zones 67 IOCG mineralization 67 airborne magnetic anomaly 67 Detailed geological mapping 67 TDEM survey 67 surface geochemistry 66 anomaly coincident 66 Ground geophysics 66 mineralized skarn 66 airborne magnetometer 66 downhole geophysics 66 magnetometer survey 66 airborne electromagnetic survey 66 mapping geochemical sampling 66 magnetometric 66 Volcanogenic Massive Sulphide VMS 66 termite mound sampling 66 airborne geophysics 66 IP Resistivity surveys 66 VTEM conductors 66 VTEM conductor 66 surface outcrops 66 electromagnetic geophysical surveys 66 radiometric surveys 66 kimberlitic bodies 66 resistivity geophysical 66 resistivity surveys 66 EM geophysical 66 Induced Polarisation IP 66 epithermal gold vein 66 radiometric magnetic 66 gold geochemical anomalies 66 induced polarization anomalies 66 VTEM targets 66 Induced Polarization 66 outcrop sampling 66 antimony mineralization 66 penetrating electromagnetic 66 VLF surveys 66 mineralized intrusive 66 airborne radiometric anomalies 66 downhole geophysical 66 radiometric airborne 66 magnetic anomalies 66 stream sediment geochemical 66 porphyry intrusives 66 magnetic geophysical surveys 66 geophysical interpretation 66 airborne EM surveys 66 geophysical 66 IP induced polarization 66 MMI geochemistry 66 IP Resistivity 66 Aircore drilling 66 polymetalic 66 MEGATEM survey 66 Fofina 66 geochemical surveying 66 ground magnetics 66 auriferous zones 66 potentially bulk mineable 66 magnetometry 66 gold anomalism 66 mineralized quartz veins 65 gravity anomalies 65 3D Induced Polarization 65 IP chargeability anomalies 65 IP chargeability anomaly 65 stepout drilling 65 uraniferous 65 mapping prospecting 65 anomalous molybdenum values 65 IP chargeability 65 radiometrics 65 geophysics prospecting 65 IP resistivity 65 VTEM 65 VLF EM surveys 65 Soil geochemistry 65 Induced Polarization IP 65 REE mineralized 65 borehole geophysics 65 MMI anomalies 65 electromagnetic conductor 65 geochem anomalies 65 mineralized zones intersected 65 palaeochannels 65 disseminated magnetite 65 anomalous geochemistry 65 coincident gravity 65 kimberlitic 65 radiometric anomalies 65 geophysical geochemical 65 cobalt mineralization 65 Geologic mapping 65 geophysical surveys 65 Delineation drilling 65 3D induced polarization 65 Rare Earth Element REE 65 outcropping mineralization 65 magnetic geophysical 65 Sian Praso 65 airborne magnetic radiometric 65 Juanicipio Vein 65 Mankarga 5 65 excavator trenching 65 VLF EM survey 65 auger drilling 65 conductivity anomalies 65 porphyry intrusions 65 radon anomalies 65 Las Boquillas 65 petrography 65 northerly trending 65 airborne radiometrics 65 massive sulphide deposits 65 airborne geophysical surveying 65 surface geochemical sampling 65 molybdenum tungsten 65 fault splays 65 airborne electromagnetic anomalies 65 resistivity anomalies 65 Lone Pine Property 65 magnetic susceptibility 65 prospective stratigraphy 65 aircore 65 uranium anomalism 65 MEGATEM 65 Central Mineralised Zone 65 detailed airborne magnetic 64 geochemically anomalous 64 EW trending 64 IP geophysical 64 TDEM 64 airborne anomalies 64 stockwork vein 64 soil geochemical anomalies 64 geophysical surveying 64 Calandria Sur 64 Tortigny deposit 64 electromagnetic EM geophysical 64 detailed geologic mapping 64 coincident induced polarization 64 geology geochemistry 64 Tagpura 64 PGM mineralization 64 untested geophysical 64 detailed aeromagnetic survey 64 radiometric surveying 64 nickel sulphide mineralization 64 CSAMT survey 64 untested geophysical anomalies 64 soil geochemistry 64 Induced Polarization IP chargeability 64 resistivity surveying 64 aircore drilling 64 soil geochemical sampling 64 soil geochemical surveys 64 geophysics trenching 64 Geotech VTEM 64 coincident anomalous 64 induced polarization geophysics 64 ultramafic sequence 64 EM anomaly 64 radiometric survey 64 geochemical 64 skarn deposits 64 stream sediment geochemistry 64 Ni Cu mineralization 64 gabbro dykes 64 Thor Trend 64 petrographic 64 layered ultramafic 64 lithological contacts 64 Induced Polarisation 64 stockwork breccia 64 altered rhyolite 64 quartz tourmaline breccia 64 geochemical surveys 64 soil geochemical 64 aeromagnetic anomalies 64 volcanogenic massive sulfide 64 bulk mineable gold 64 mineralized alteration 64 Lac Cinquante deposit 64 gravity anomaly 64 VLF EM 64 eluvial 64 mafic intrusions 64 Zone Bambadinka 64 magnetometer surveys 64 ground magnetometer surveys 64 Ida Dome 64 mapping geochemistry 64 geochemical soil 64 adit sampling 64 Renard cluster 64 Colnic 64 northwesterly trending 64 anomalous zones 64 Mt Penck 64 Cu Au mineralization 64 manganese mineralization 64 Taricori 64 geological reconnaissance 64 airborne radiometric magnetic 64 Bronson Slope deposit 64 silica breccia 64 kimberlitic indicator minerals 64 Carotare 63 induced polarization resistivity 63 sulphide bearing 63 carbonatite complex 63 Cu Zn 63 Cobrecon 63 Soil sampling 63 radiometric anomaly 63 mineralized shear zone 63 Shirotnaia zone 63 airborne magnetics 63 REE occurrences 63 Muirs Reef 63 Eagle Nest deposit 63 epithermal gold mineralization 63 orogenic gold 63 Banded Iron Formation 63 electromagnetic anomaly 63 vanadium mineralization 63 Sicera Norte 63 Roughrider East 63 Etango deposit 63 Kasala Main Zone 63 mapping trenching 63 mineralized hydrothermal 63 Sunbeam Pettigrew property 63 geophysical survey 63 auger drill 63 Fayolle property 63 mineralizing system 63 mesothermal gold 63 gossans 63 NSAMT 63 geochem 63 tungsten mineralization 63 approximately #km# [002] 63 Sisson Brook 63 Klaza Zone 63 diamondiferous kimberlite 63 Letitna 63 AeroTEM III 63 aeromagnetic survey 63 volcanogenic massive sulphide VMS 63 Diabase Peninsula uranium 63 intersected anomalous 63 aeromagnetic surveys 63 resource delineation 63 Calandria Norte 63 F2 Zone 63 IP Resistivity survey 63 sylvinite 63 ground geophysical surveying 63 PGE mineralization 63 bearing stratigraphy 63 geochemical anomalies 63 Kena Property 63 volcanic stratigraphy 63 northeasterly trending 63 Airborne geophysics 63 copper molybdenum silver 63 Mouchalagane 63 Hambok 63 resolution airborne magnetic 63 downhole EM 63 Gongondy 63 IP resistivity survey 63 Clementine vein 63 Airborne EM 63 Jahodna 63 anomalous soil geochemistry 63 litho geochemical 63 ground radiometric surveys 63 disseminated sulphide mineralization 63 kimberlite dyke 63 magnetic geophysical anomalies 63 structural stratigraphic 63 bearing kimberlite 63 silicified zone 63 geophysical anomaly 63 coincident chargeability 63 radiometric geophysical survey 63 bulk minable 63 niobium mineralization 63 bedrock conductors 63 Higo Blanco 63 prospecting geological mapping 63 leachable copper 63 surface trenching 63 ground geophysical surveys 63 geochemical samples 63 Reverse Circulation drilling 63 Bellechasse Timmins 63 RAB drilling 63 spectrometric 63 mafic ultramafic rocks 63 resistivity lows 63 kimberlitic indicator mineral 63 Cuiu Cuiu 63 ground geophysics 63 NNW trending 63 Itilima 63 ultramafic rock 62 previously undrilled 62 chromitite 62 Azulitas 62 polymetallic vein 62 chargeability anomalies 62 electromagnetic EM survey 62 geochemistry anomalies 62 soil geochemical anomaly 62 VTEM geophysical survey 62 bulk mineable 62 Pulse EM 62 Oshiveli 62 mineralized breccia 62 magnetite skarn 62 geological mapping prospecting 62 Yaragua 62 electromagnetic EM conductors 62 gabbro intrusive 62 Sulphide Shear Zone 62 kilometer airborne magnetic 62 Black Thor chromite 62 resistivity anomaly 62 Quebrada Verde 62 bulk tonnage mineralization 62 Greenschist Zone 62 mineralized pegmatite 62 auriferous 62 ultramafic intrusives 62 WDC# 62 geophysical prospecting 62 ENE trending 62 GEOTEM survey 62 excavator trenches 62 NNE trending 62 geochemical anomaly 62 Enzyme Leach soil 62 geologic mapping 62 Rovina porphyry 62 anomalous Au 62 geophysical induced polarization 62 calcrete sampling 62 sulphide occurrences 62 mineralized shear 62 Ni Cu PGM 62 kimberlite occurrences 62 Alaskite 62 mineralized boulder 62 FDN deposit 62 quartz reef 62 Bokan Dotson Ridge 62 airborne geophysical surveys 62 mineralising 62 Ni Cu PGE mineralization 62 electromagnetic EM 62 Rojo Grande 62 alteration zones 62 silicified breccia 62 heliborne magnetic 62 chromite mineralization 62 Cordero Porphyry 62 metallogenic 62 bearing sulphide mineralization 62 Wollaston Domain 62 La Lechoza Prospect 62 open pitable 62 Geochemical sampling 62 penetrating geophysical 62 peridotites 62 Tantamaco 62 Mikwam 62 structural lineaments 62 Las Bolas deposit 62 molybdenum porphyry 62 Guajes West 62 Dadiangou 62 spodumene bearing 62 mineralization encountered 62 volcano sedimentary belt 62 Radiometric 62 Hache lens 62 Allammaq 62 skarn mineralization 62 massive sulfide mineralization 62 BHEM surveys 62 Au Cu Ag 62 copper molybdenum porphyry 62 IP geophysical surveying 62 graphitic sediments 62 Culebrilla 62 Geophysical surveying 62 porphyry style 62 Carbonatite Complex 62 structural lineament 62 VTEM airborne geophysical 62 Yaxtche deposit 62 potentially open pittable 62 induced polarization geophysical 62 pathfinder elements 62 mineralized corridor 62 copper skarn 62 Abitibi Geophysique 62 VTEM airborne surveys 62 massive sulphide lenses 62 Surface sampling 62 previously unsampled 62 anomalous uranium 62 quartz sericite pyrite alteration 62 Manzako Prospect 62 Kay Tanda 62 airborne EM anomaly 62 NE trending 62 geochemical assays 62 Luhwaika 62 aircore drill 62 Eldor Project 62 pyrophyllite 62 auger sampling 62 epithermal quartz veins 62 reconnaissance prospecting 62 Okohongo target 62 breccia mineralization 62 carbonate veins 62 resolution aeromagnetic survey 62 Matoush fault 62 BLEG 62 aeromagnetic 62 magnetite alteration 62 bulk minable gold 62 quartz stockworks 62 Moly Dome 62 porphyry mineralization 62 granodiorite porphyry 62 mafic ultramafic 62 El Domo 62 Klappibacken 61 geological mapping geochemical sampling 61 gold arsenic antimony 61 Toro Gregorio 61 arsenic anomalies 61 intersected mineralized 61 Paymaster Canyon 61 vein breccia 61 Enzyme Leach 61 Guadalupe Manto 61 Nithi Mountain 61 mafic intrusion 61 Preliminary metallurgical testwork 61 Pb Zn Ag 61 AeroTEM 61 sulphide alteration 61 Kaniago 61 geologically mapped 61 mineralized porphyry copper 61 InfiniTEM 61 Au Cu 61 porphyry skarn 61 Induced Polarization anomaly 61 magnetite pyrite 61 Simuku 61 silicic 61 Ciresata 61 Induced Polarization surveys 61 basaltic rocks 61 disseminated sulphide 61 soil geochemistry anomaly 61 molybdenite mineralization 61 kimberlite indicator mineral 61 polymetallic mineralization 61 massive sulphide horizon 61 jasperoids 61 Systematic sampling 61 trench sampling 61 aeromagnetic data 61 Kangaluwi 61 Guayabales 61 IOCG targets 61 PGEs 61 kimberlite breccia 61 shear veins 61 Harena 61 Fofina Zone 61 Ixtaca zone 61 Ground geophysical surveys 61 VTEM airborne magnetic 61 helicopter borne VTEM 61 radiometric readings 61 dravite 61 skarn deposit 61 epithermal vein 61 copper mineralization intersected 61 PdA Extension 61 trending shear zone 61 KIMs 61 mineralized vein 61 sulphide deposits 61 lithium tantalum 61 skarn alteration 61 mineralized drill intercepts 61 sampling trenching 61 Quantec Titan 61 quartz sulphide vein 61 metal zonation 61 Shivee West 61 kimberlite indicator minerals 61 Puajanca Zone 61 lapilli tuff 61 copper sulphides 61 quartzite ridge 61 aeromagnetics 61 Rio Zarza 61 Amaruk property 61 shallowly dipping 61 diatremes 61 footwall alteration 61 Naciente Quebrada Pedregosa 61 Junnagunna 61 Dubenski property 61 hole CJV 61 massive sulphide VMS 61 Upper Fir 61 Kenge target 61 linecutting 61 polymetallic deposit 61 South Minita 61 outcropping vein 61 scintillometer surveys 61 mineralized breccias 61 prospecting mapping 61 Magusi deposit 61 airborne magnetometer survey 61 Suuri zone 61 stockwork zone 61 Cu Au porphyry 61 mineralizations 61 Norpax Deposit 61 hydrothermally altered 61 ultramafic sill 61 anomalous radiometric 61 MMI anomaly 61 Aricheng West 61 Roughrider Zone uranium 61 porphyry Cu Mo 61 Miwah Gold Zone 61 Shirotnaia 61 induced polarization anomaly 61 volcanic massive sulphide 61 Extension Occurrence 61 diamondiferous kimberlite pipes 61 Goldpines North 61 ultramafic rocks 61 Dioulafoundou 61 polymetallic veins 61 exhalative 61 iron carbonate alteration 61 IP Induced Polarization 61 Sulfato 61 RC drillholes 61 magneto telluric 61 coincident geochemical 61 spodumene bearing pegmatite 61 dike swarm 61 sulphide mineralized 61 Roughrider uranium 61 epithermal gold targets 61 Fugro airborne 61 mineralogical studies 61 Ni Cu PGE 61 Middle Eocene 61 mineralized outcrop 61 GEOTEM 61 Kelex 61 meter spacing 61 Tapuli Stora Sahavaara 61 gradient array 61 Torlon Hill 61 Titan# 61 quartz monzonite intrusive 61 Pellivuoma 61 mechanical trenching 61 Geochemical analysis 61 geophysical signatures 61 vein stockwork 61 bearing hydrothermal 61 gamma logging 61 palaeochannel 61 jasperoid 61 Roughrider uranium deposit 61 Igunda 61 Zafranal 61 detailed geological mapping 61 garnet skarn 61 potassically altered 61 komatiitic 61 carbonatite dykes 61 bearing quartz vein 61 Marge Vein 61 JAK Zone 61 sub Athabasca unconformity 61 pyrite alteration 61 nickel laterite mineralization 61 Cluff Lake 61 Chimiwungo 61 mineralized diorite 61 carbonaceous shale 61 soil sampling trenching 61 Pasfield Lake 61 Cu Ni 61 epithermal alteration 61 ultrabasic 61 trenching sampling 61 stratigraphically below 61 syenite intrusive 61 conductive anomaly 61 strongly silicified 61 magnetic lineaments 61 anomalous mineralization 61 mineralized hydrothermal breccia 60 sulfide mineralization 60 Yanfolila 60 aero magnetic 60 Zafranal Main Zone 60 Handeni Gold Trend 60 Cerro Moly 60 stratigraphic sequence 60 Sicera Sur 60 magmatic nickel copper 60 surficial 60 pole dipole 60 MMI soil geochemistry 60 Z TEM 60 Tassawini 60 Mobile Metal Ions 60 Soil geochemical 60 Hushamu 60 hematite mineralization 60 layered mafic 60 Kuriskova 60 Silica Ridge 60 alluvial workings 60 intersected sulphide mineralization 60 intrusive breccia 60 Butia prospect 60 Cordillera del Condor 60 Onaman 60 Ni Cu PGM mineralization 60 airborne VTEM survey 60 Dioulafoundou zone 60 exhalite 60 breccia pipes 60 Cretaceous sandstones 60 mineralized gabbro 60 #WR# 60 Despoblados 60 chromite occurrences 60 malachite mineralization 60 geologic modeling 60 Vaquillas 60 La Bodega zone 60 Soquem 60 gold porphyry mineralization 60 rhyolite tuffs 60 mineralized horizon 60 geophysical anomalies 60 petrological 60 Southwest Oyu 60 Lac Cinquante 60 felsite 60 kimberlite dykes 60 Candelones 60 alteration halo 60 inversion modeling 60 Sinchao Property 60 Kambalda style 60 platinum palladium mineralization 60 Lalor deposit 60 infill sampling 60 Cumpie Hill 60 Norlartic 60 subparallel 60 supergene zone 60 Encanto Zone 60 REE deposits 60 Ormsby Zone 60 Kavola East 60 ultramafic mafic 60 silica carbonate 60 poly metallic mineralization 60 chlorite sericite 60 copper molybdenum mineralization 60 Itigi Manyoni Uranium 60 vein swarms 60 mineral occurrences 60 massive sulphide lens 60 El Compas 60 Quantec 60 alaskite 60 gossanous 60 copper molybdenum gold 60 quartz adularia veins 60 amphibolites 60 niobium tantalum 60 copper nickel sulphide 60 tungsten tin 60 deformation zone 60 Klaza property 60 geological geochemical 60 Goldcliff 60 quartz stockwork zone 60 Brecha Limite 60 Malrok 60 dyke swarms 60 geological modeling 60 gold mineralization intersected 60 airborne geophysical survey 60 Ruhuhu 60 sulfide bearing 60 porphyry copper mineralization 60 Accha deposit 60 diamond drillholes 60 gold geochemical anomaly 60 mineralized shears 60 supergene mineralization 60 Mechanical trenching 60 Laterite 60 Quantec Geoscience 60 Tres Juanes Norte 60 Malartic Lakeshore property 60 phyllosilicate 60 anomalous concentrations 60 mineralized dykes 60 anomalous molybdenum 60 Ag Pb Zn 60 massive sulphide zones 60 lithologic 60 gold mineralized quartz 60 surface bulk tonnage 60 leached capping 60 anomalous REE 60 DUB# 60 airborne EM conductors 60 quartz sericite alteration 60 microprobe analyzes 60 multielement 60 specular hematite 60 delineation drill 60 prospecting trenching 60 geological interpretations 60 granitic pluton 60 pathfinder element 60 soil geochemistry surveys 60 Sudbury Breccia 60 granitoids 60 Fayolle deposit 60 Au Cu porphyry 60 ground geophysics trenching 60 lithology 60 IP geophysical anomaly 60 chargeability resistivity 60 geophysical surveys trenching 60 stockwork veining 60 Drill hole SADD# 60 Wicheeda 60 Sulphurets deposit 60 REE mineralization 60 Lunguya 60 quartz carbonate vein 60 open pittable 60 sulphide intersections 60 infill drill 60 komatiite 60 coincident EM 60 Main Lode 60 drillholes 60 felsic tuff 60 Akasaba Mine 60 BIF outcrops 60 NQ diamond 60 stratigraphic interval 60 Kirana Break 60 sulphidation 60 Ouro Roxo 60 Minas Corani 60 Kutcho 60 mineralized shear zones 60 gamma ray spectrometry 60 geophysical geological 60 alteration halos 60 Norra Karr 60 Dombraly 60 Leitch Sand River 60 gold mineralizing 60 sedex 60 mineralized boulders 60 Ixtaca 60 Marban deposit 60 variably mineralized 60 Wona 60 Gwenivere 60 Unconformity 60 Musley Deposit 60 Anuri kimberlite 60 hypogene copper mineralization 60 Golouma West 60 ignimbrite 60 gabbro dyke 60 geological mapping 60 volcanogenic massive sulphide 60 advanced argillic alteration 60 subvertical 60 Tranquilo Trend 60 #m@#.#g t gold [002] 60 geochemical sampling 60 geochemical assay 60 VMS mineralization 60 evaporite 60 chalcocite mineralization 60 Porphyry copper 60 reconnaissance mapping 60 vein outcrops 60 andesitic rocks 60 magnetic anomaly 60 intersect mineralization 60 porphyries 60 geomechanical 60 mineral assemblages 60 chalcedonic 60 Nose Deposit 60 geochemical analyzes 60 Adumbi Prospect 60 volcanogenic 60 Sudbury Igneous Complex 60 alaskites 60 silica alteration 60 Kurupung Batholith 60 Pelusa Property 60 dipole dipole 60 drillhole database 60 Reverse Circulation 60 gamma ray logs 59 East Acma 59 artisanal workings 59 PGM deposit 59 VTEM Survey 59 Xietongmen deposit 59 Thelon Basin 59 mafic intrusives 59 hydrothermal alteration 59 trenching 59 skarn zones 59 favorable stratigraphy 59 soil geochemistry anomalies 59 Hoidas Lake 59 Preliminary metallurgical 59 sampling geological mapping 59 outcropping quartz veins 59 Gravity Survey 59 sulphidation epithermal 59 Yaxtche zone 59 Heruga 59 trenching mapping 59 induced polarization IP chargeability 59 argentiferous 59 geological mapping geochemical 59 South Miwah Bluff 59 Geotechnical drilling 59 NQ diamond drilling 59 Nyota Prospect 59 metasedimentary 59 low sulphidation 59 carbonate alteration 59 flotation testwork 59 sandstone horizons 59 massive sulphide intersections 59 Skukum 59 arcuate 59 Emba Derho 59 Cannivan Gulch 59 Abel Knoll 59 sulphide zones 59 igneous intrusive 59 NQ diamond drill 59 mineralized quartz vein 59 Artavasdes 59 Bokan Mountain 59 Maybrun 59 Cordero Porphyry Belt 59 rhyolite dome 59 Piaba 59 Barre de Fer 59 Peppler Lake 59 Sudbury breccia 59 Hinge zones 59 Tertiary volcanic rocks 59 Radiometric surveys 59 manto mineralization 59 Golouma South 59 Proterozoic age 59 carbonatite 59 borehole EM 59 Bepkong 59 diamondiferous kimberlites 59 Valdecanas Vein 59 electrical resistivity 59 metallurgical characteristics