Related by context. All words. (Click for frequent words.) 60 intersected mineralized zones 60 Minapampa East 60 intersected anomalous 60 Au Cu mineralization 60 drill hole NAD# 59 El Orito vein 59 BB# [002] 59 molybdenite mineralization 59 ppm eU#O# 59 #m@#.#g t Au [001] 59 True thicknesses 59 Extension Occurrence 59 El Compas vein 58 disseminated sulphide 58 bearing sulphide mineralization 58 massive sulphide mineralization 58 anomalous soil geochemistry 58 Nyafe 58 strongly silicified 58 Megabuck Zone 58 #m@#.# g t Au [001] 58 vein outcrops 58 intersected #.#m [001] 58 #ppb gold 58 Marta Este 58 silicified zone 58 drillhole intersected 58 downhole lengths 58 mineralized quartz vein 58 South Minita 57 Mineralized intersections 57 Thor Vein 57 drill hole HR# 57 stringer mineralization 57 #g t Au [001] 57 intersected #.#m [002] 57 coincident anomalous 57 Tortigny deposit 57 Junnagunna 57 Discovery Outcrop 57 hole WAT# 57 kimberlitic material 57 #WA 57 acid leached 57 #m@#.# g t Au [007] 57 quartz adularia veins 57 stockwork veining 57 Mineralized intercepts 57 chromitite layers 57 #m@#.# g t [004] 57 Molybdenum Mo 57 Takom 57 Animas vein 56 Cu Au mineralization 56 #.#g Au t [003] 56 Snowfield Zone 56 section #E [003] 56 potassically altered 56 WAT# #A 56 Hole EC# 56 metres@#.# g t Au [003] 56 ultramafics 56 vuggy silica alteration 56 drillhole spacing 56 quartz pyrite veins 56 averaging #.#g t [003] 56 Gongondy 56 mineralization assaying 56 hole DDH# 56 leached capping 56 intrusive breccia 56 hole MWNE 56 Mineralized zones 56 mineralizations 56 #g t Au [002] 56 NQ diamond 56 #m@#.#g t Au [003] 56 metres@#.# g t Au [002] 56 drilled thicknesses 56 Anomalous radioactivity 56 5g t 56 chalcocite mineralization 56 sulphide breccia 55 sulphide stringers 55 intersected anomalous gold 55 veins stockworks 55 Chromitite 55 sericitic 55 QAP DDH 55 #ppb Au [002] 55 Minapampa Zone 55 vein intercepts 55 Caballos Formation 55 Drill intersections 55 hole HR# 55 #RB# 55 geologically mapped 55 Minita deposit 55 meters grading #.#g [001] 55 weakly mineralized 55 drill hole MWNE 55 #.#g t gold [001] 55 hole WAT# #A 55 YAR# 55 garnet skarn 55 diorite porphyry 55 #m@#.#g t [006] 55 #.#g t [005] 55 Mineralized intervals 55 silica pyrite 55 hypogene mineralization 55 PdA Extension 55 #.# meters downhole 55 stringer sulphides 55 carbonate veins 55 Anomalous uranium 55 subhorizontal 55 m@#.# g t Au [002] 55 #.#gpt gold [001] 55 ppm U 55 #.#g t Ag [005] 55 quartz sulphide 55 Ouro Verde deposit 54 veinlet 54 g t PGM 54 @ #.#g t [001] 54 chlorite sericite 54 1g t Au 54 DDH IAX 54 #m@#.#g t Au [002] 54 Cu Eq 54 #g t [001] 54 #m@#.#g t Au [005] 54 alunite alteration 54 rhyolite porphyry 54 skarn horizon 54 interval assaying 54 IP chargeability 54 DDH# [002] 54 #.#g Au t [002] 54 approximately #km# [002] 54 tungsten trioxide 54 Mantouchiche showing 54 #ppm Mo 54 quartz hematite 54 hole RC# 54 sulphide veins 54 #m@#.# % [001] 54 @ #.#g t [002] 54 quartz sericite 54 quartz porphyry 54 Hole IKD 54 chalcedonic 54 #ppm eU#O# 54 #m@#.#g t gold [001] 54 #CBN 54 #m@#.# % [005] 54 @ #.#g t [004] 54 #.#gpt [001] 54 stockwork breccia 54 spodumene bearing intrusives 54 #m@#.#g t Au [004] 54 mineralized interval 54 grading #.#g t Au [001] 54 TRK# 54 assay intervals 54 chalcopyrite mineralization 54 copper equivalent CuEq 54 hole GW# 54 #m@#.# g t Au [006] 54 metres@#.#g t gold 54 GPD# 54 intersected kimberlite 54 SIN# 54 oz t Au 54 heap leach recoveries 54 magnetite pyrite 54 Au Eq 54 vein assayed 54 intersect mineralization 54 downhole depth 54 hole #VK 53 ppm indium 53 #.#g t gold [005] 53 variably altered 53 #m@#.# g t [002] 53 pyrite pyrrhotite chalcopyrite 53 #m@#.# g t Au [002] 53 Upper Fir Carbonatite 53 #.#g t silver [003] 53 Timmins Porcupine West 53 palladium Pd 53 itabirite 53 holes DDH 53 #m downhole 53 arsenopyrite mineralization 53 meterage 53 intersected anomalous copper 53 quartz veins containing 53 #ppm U 53 epithermal quartz 53 Hapi Zone 53 pyrite mineralization 53 #.#g t Ag [003] 53 metres@#.# % [002] 53 ppm Mo 53 % Fe#O# 53 intensely silicified 53 ZFDDH# 53 Hole intersected 53 gAu t 53 biotite chlorite 53 grade Thor Vein 53 magnetite alteration 53 Naciente Quebrada Pedregosa 53 % Nb#O# 53 disseminated chalcopyrite 53 ppm Ag 53 metres@#.# % [001] 53 section #E [004] 53 sub Athabasca unconformity 53 molybdenite bearing 53 Garrcon shaft zones 53 Silver Equivalent 53 3g t 53 silicified porphyry 53 #.#gpt Au [001] 53 averaging #.#g t [001] 53 #m@#.#g t Au [006] 53 vuggy silica 53 m@#.# g t [004] 53 #.#g t [004] 53 gm t 53 Filo de Oro 53 pyrite alteration 53 #JD# 53 abundant quartz veining 53 vein swarms 53 hole NC# 53 Pt + Pd 53 dunite 53 quartz calcite 53 saprolitic 52 lapilli tuff 52 DDH# [001] 52 conductive anomaly 52 grading #.#g t [001] 52 pyrite sphalerite 52 Leprechaun Pond 52 #m grading #.#g [002] 52 #.#g t silver [004] 52 AZS# 52 #.# gpt silver 52 DDH E# 52 m@#.# g t Au [004] 52 #g t [002] 52 anomalous Cu 52 g t Ag 52 metres@#.# % [003] 52 rockchip 52 #m@#.# g t [006] 52 gAu tonne 52 banded quartz 52 chlorite carbonate 52 % TCu 52 artisanal shafts 52 net textured sulphides 52 brecciation 52 #.#g t Au [004] 52 pentlandite 52 shearing alteration 52 granitoids 52 drilled widths 52 disseminated pyrrhotite 52 diopside 52 stringer sulphide mineralization 52 Copper Cu 52 hole SP# 52 meters@#.# g t Au 52 vein breccias 52 gold arsenic antimony 52 biotite alteration 52 meters grading #.#g [002] 52 Merensky Reef 52 pyrite altered 52 TCu 52 g t Aueq 52 #-# intersected 52 Oshiveli 52 quartz sericite alteration 52 siliceous sediments 52 disseminated sulphide mineralization 52 McFaulds # 52 holes BD# 52 chalcocite chalcopyrite 52 quartz carbonate vein 52 pelitic gneiss 52 #.#gpt [004] 52 sphalerite galena 52 gms tonne 52 D# #B 52 #.#g t Au [002] 52 Zn mineralization 52 andesite flows 52 aplite 51 quartz tourmaline veins 51 % Cu Eq 51 hydrothermal breccias 51 #m@#.# % [004] 51 SLD# 51 Drill hole GCL# 51 gamma logging 51 m@#.# g t Au [003] 51 Pulacayo deposit 51 abundant pyrite 51 @ #.#g t [003] 51 Marge Vein 51 intersected widths 51 -Greg Stoda Palm Beach 51 #,# g t 51 intercept grading 51 Significant Intercepts 51 Bamoos 51 mineable resource 51 #m@#.# g t [005] 51 #.#g Au t [005] 51 Thrust Package 51 Hole ZFDDH# 51 oz ton Au 51 argillic altered 51 Animas Vein 51 acid soluble 51 m@#.# g t [003] 51 Cr#O# 51 metres@#.# g t [001] 51 Scadding Gold 51 Bananghilig Deposit 51 quartz carbonate 51 biotite altered 51 #m@#.# % [007] 51 J1B 51 disseminated stringer 51 #m@#.# % [006] 51 EUG# 51 oz Au t 51 scheelite 51 Tatajuba 51 altered peridotite 51 #m@#.# % [002] 51 True Width 51 pyrrhotite chalcopyrite 51 KDH# [001] 51 hole PLRC 51 Sulphide mineralization 51 grading #.#g t [002] 51 scintillometers 51 anomalous REE 51 hypabyssal kimberlite 51 pyrargyrite 51 #.#g t Ag [004] 51 carbonate vein 51 g/cm3 51 ppm U#O# 51 chalcopyrite pyrite 51 #m@#.# % [003] 51 True widths 51 composited assay 51 #.#gpt [002] 51 g t grammes 51 hole ZFDDH# 51 intersected mineralized zone 51 mineral zonation 50 ppm Pb 50 anomalous radioactivity 50 #m@#.#g t gold [002] 50 Li# 50 chalcopyrite pyrrhotite 50 Brimstone leach pad 50 Mallery Stockwork 50 LMD# 50 blebby 50 quartz pyrite vein 50 sericite pyrite 50 quartz feldspar 50 g mt 50 epidote chlorite 50 metres@#.# g t [003] 50 angular boulders 50 stockwork zones 50 Star Kimberlite 50 Nb#O# 50 hole BG# 50 Anuri kimberlite 50 limonitic 50 coincident induced polarization 50 #m@#.#g t [002] 50 KBDD# 50 disseminated sulphides 50 DDH #A 50 Zn Cu Ag 50 g t TPM 50 quartz breccia 50 pyrrhotite mineralization 50 Bossier Haynesville 50 oz t Ag 50 eU#O# 50 locally graphitic 50 #.#g t Au [005] 50 AngloGold Ashanti Titiribi 50 grading #.#g t Au [002] 50 gms tonne gold 50 gms tonne silver 50 copper Cu 50 FNX# 50 #.#gpt [003] 50 t Au 50 #ppb Au [001] 50 stockwork veinlets 50 gm t Au 50 hole NAD# 50 tonne Au 50 LC#C 50 #.#gpt gold [002] 50 Upper Montney 50 Significant assay 50 airborne radiometric survey 50 semi massive sulphides 50 quartz veinlets 50 Kau# 50 azimuthal 50 quartz feldspar gneiss 50 GW# [001] 50 GAX# 50 #m@#.#g t [001] 50 Cannu zone 50 #g t Ag [001] 50 EXD# 50 ppm Au 50 CuT 50 pyroxenite 49 MRC# [002] 49 % Cr#O# 49 BRAZD 49 oz ton gold 49 seam thickness 49 mineralization grading 49 NQ diameter core 49 minor chalcopyrite 49 SADD# 49 #.#g t [003] 49 averaging #.#g t [002] 49 IP geophysical anomaly 49 Abel Knoll 49 #ppm molybdenum [001] 49 stockwork veins 49 disseminated sphalerite 49 underground adits 49 IP geophysical surveys 49 Significant Intersections 49 granitic gneiss 49 #mV V 49 #.#g t silver [002] 49 meter spacing 49 propylitic alteration 49 KDH# [002] 49 hole DH# 49 Hole PXE 49 TC# #c 49 intercept widths 49 mineralized sandstone 49 TRDH 49 #m@#.# g t Au [005] 49 hole TL# 49 Hibou dyke 49 #.#g t Au [006] 49 % MoS2 49 #ppm Cu 49 % CuT 49 #.#g t [006] 49 pyrrhotite pyrite 49 pyrite chalcopyrite 49 g t Pt 49 mineralized porphyries 49 meters downhole 49 ICE# [002] 49 Ultramafic rocks 49 g Ag 49 m@#.# g t Au [001] 49 Mineralization consists 49 Hole BL# 49 Creston Molybdenum Deposit 49 #g t [003] 49 ppm Ta#O# 49 proprietary 3D seismic 49 Bulk density 49 oz Au ton 49 Cu Equivalent 49 + Y#O# 49 KBRC# 49 bornite chalcopyrite 49 #ppm molybdenum [002] 49 magmatic kimberlite 49 Ag Eq 49 syenite gneiss 49 galena sphalerite 49 Imwauna 49 Brucejack Area 49 #ppm U#O# 49 Section #E [001] 49 net Cardium horizontal 49 + Pd + 49 tonnes@#.# g t [002] 49 TC# #d 49 g t Pd 49 Lynx Hibou system 49 g t PGE 49 search ellipsoid 49 #m@#.# g t Au [003] 48 anomalous arsenic 48 meters@#.# g t [002] 48 Widths 48 El Cafetal La Virgen 48 Masato Deposit 48 gpt Pt 48 pyrite pyrrhotite 48 #CF# 48 ESI# 48 g t AuEq 48 #m@#.#g t [003] 48 inferred ounces 48 #.#g t Ag [001] 48 m grading 48 KRC# [001] 48 magnetite chalcopyrite 48 Lower Caballos 48 multistage frac 48 fuchsite 48 #.#g Ag t 48 hole MJV 48 #m@#.# g t [003] 48 altered ultramafic rocks 48 drill hole ZFDDH# 48 WDD# 48 Buriti trend 48 allanite 48 ppm Cu 48 #.#m #.#m [004] 48 Mbenge Zone 48 equivalent CuEQ 48 Section #N [002] 48 meter spacings 48 metallurgical flowsheet 48 chalcocite 48 potentially mineable widths 48 Wilrich horizontal 48 #.#g t Au [003] 48 approx.# [001] 48 #.#nm [002] 48 ordinary Kriging 48 Assay intervals 48 ppm Zn 48 unconformity intersected 48 millidarcies 48 sulphide veinlets 48 g t Au Eq 48 Inferred Category 48 % Cu #.#g 48 ZrO 2 48 g t Au eq 48 gamma ray logs 48 TWDDH 48 metres@#.#g t Au 48 adularia 48 #E [002] 48 #.#g/tAu 48 grammes tonne 48 Indicated Category 48 horizontal laterals 48 g t Beryllium 48 meters downhole depth 48 oz.Au 48 volcaniclastic rocks 48 ppb Pt 48 m downhole 48 Significant intercepts 48 % WO3 48 Vianey Mine 47 HBET# 47 True Widths 47 #,#,# tonnes@#.# g [002] 47 massive sulphides grading 47 oxides TREO 47 Belleterre mine 47 Dip -# 47 copper #.#g t [002] 47 Au t 47 hole BA# 47 Significant intersections 47 Au eqv 47 ppm molybdenum 47 Y#O# 47 #.#oz t [002] 47 TSX LSG 47 #m@#.#g t [004] 47 Hole LL# 47 smokey quartz 47 tonnes grading #.# 47 t/m3 47 defined shallowly dipping 47 Marathon PGM Corp 47 insitu 47 Diamond Drill Holes 47 Kerr Sulphurets 47 Snowfield Project 47 Cu mineralization 47 ppb Pd 47 exhalite horizon 47 Strongly anomalous 47 outcropping quartz 47 HQ NQ 47 #.#m downhole 47 trace chalcopyrite 47 Hole ICE# 47 JPN# 47 4E PGM 47 mV V 47 RRC# 47 CuEQ 47 #.#g t gold [004] 47 cyanide soluble 47 semi massive sulphide 47 Copper Equivalent 47 intermediate volcanic rocks 47 3E PGM 47 #.# oz Au 47 quartz chalcopyrite 47 ppm cobalt 47 zinc Zn 47 % P#O# 47 drill hole GCL# 47 argentiferous galena 47 oz ton silver 46 spodumene bearing pegmatites 46 pyrrhotite pyrite chalcopyrite 46 Early Joli Fou 46 #g t Ag [002] 46 tons@#.# [001] 46 true widths 46 W ROCK ISLAND 46 Fayetteville Shale acreage 46 t Pd 46 tungsten WO3 46 indicator kriging 46 -Keichi 46 garnet biotite 46 gm tonne 46 quartz biotite 46 airborne magnetometer survey 46 - -Gundberg 46 azimuth 46 vanadium pentoxide V#O# 46 Hawkville Field 46 kimberlite intersections 46 pervasive silicification 46 #m@#.# g t [001] 46 HOLE NO 46 ft md 46 interval grading #.#g 46 RCD# 46 meters@#.# g t [001] 46 KERC# 46 MGZD# [002] 46 ppm eU 46 % CuEQ 46 Fig. 4B 46 Wireline logs 46 ppm arsenic 46 #.#g t [002] 46 variography 46 Skukum 46 MK RC 46 perforations #,#-#,# feet [002] 46 DDD# 46 kriged 46 Auden Property 46 Goldsource discovery 46 #.#m [003] 46 #.# VOY UZ 46 #Ω [002] 46 #.#ft [005] 46 cpht 46 g t Au MGZD# 46 #.#g t Ag [002] 46 Horizontal wells 46 oz ton Ag 46 horizontal Haynesville shale 45 ppm boron 45 silver #.#g t 45 Metres Averaging 45 Lebork S 1 45 Mt@#.# g t Au [001] 45 oz st 45 NiEq 45 Muskox kimberlite 45 g.Au t 45 #.#g t gold [003] 45 Assays Pending 45 carbonaceous mudstone 45 AgEq 45 variogram range 45 Sinaloa Batholith 45 magmatic massive sulphides 45 Ta#O# 45 geologic interpretations 45 intercepts approximate 45 Haynesville Bossier horizontal 45 #.#Mt grading [003] 45 pyrrhotite 45 potassic altered 45 Grams Per Tonne 45 ^ sup -1 45 g t Au CHL# 45 Core Length 45 Vanadium V#O# 45 gpt Ag 45 gradational 45 # KBDD# 45 #.#g t PGE 45 % Cu #.#g/tAu 45 Million ozs 45 DDHC 45 Au incl 45 TC# #b 45 + Pd g t 45 niobium oxide Nb#O# 45 AuEq 45 gpt Pd 45 NAD# [001] 45 carbonate sericite 45 anisotropy 45 hydrocarbon saturations 45 #.#Mt grading [001] 45 % Zn 45 Indicated mineral 45 per tonne gpt 45 #.#g t Au [001] 45 ft. TDD 45 grams tonne 44 Au CHL# 44 @ #ppm U#O# 44 gpt silver 44 gold equivalent AuEq 44 eU 3 44 g t 4E 44 Inferred ounces 44 zinc #.#g t 44 #m@#.#g t [005] 44 Tres Chorreras 44 #.#g t PGM 44 m@#.# % 44 Crocotta 44 #.#g t [001] 44 - -Schwenkler 44 Mothae pipe 44 DDH LAT 44 medium grained 44 g t indium 44 ppb Ag 44 Dy#O# 44 Drill composites 44 ounces 4E 44 #/lb Mo 44 mineralized uncut 44 Rh + 44 arcsecond 44 #,#-#,# ft. Loc 44 Aueq 44 Cretaceous limestones 44 Atoka formations 44 Drill hole LN# 44 #.#/#.#m 44 coincident 44 cmg t 44 Tonnages 44 #.#-#.# m [001] 44 #N [003] 44 inferred tonnes grading 44 -human papilloma viruses 44 OGIP 44 -Baralt 44 copper #.#g t [001] 44 Ordinary Kriging 44 - -Anne Milling 44 #g t Ag [003] 44 mu m 44 ZrO2 44 Burkley Phillips No. 44 Mt@#.# g t [001] 44 phlogopite 44 hole intersected unaltered 44 mm f/#.#-#.# 44 www.malbex.ca 44 Lagunas Norte Pierina 44 oxyhemoglobin 44 Measured Depth 44 AVO anomaly 44 THENCE SOUTH 44 #.# MHz [002] 43 perforations #,#-#,# feet [003] 43 #.#m #.#m [005] 43 anterolateral 43 - -Justice Timothy Studdert 43 @ #ppm eU#O# 43 g t palladium 43 pyrite magnetite 43 #.# oz ton 43 ε 43 FWHM 43 align = alignright 43 ppm antimony 43 sigmoidal 43 Petro Reef anticipates 43 Fig. 1a 43 #:#,# scale [002] 43 oz t 43 gamma logs 43 % copper #.#g 43 tonnes@#.# g t Au [002] 43 Ce#O# 43 Massive Sulphides 43 #.#lb/#.# 43 1μm 43 t Ag 43 fragment shader 43 arcminutes 43 mineable reserve 43 Au EQ 43 interval grading 43 gm t Ag 43 m@#.# 43 tons@#.# % 43 ATW Transaction 43 regression coefficients 43 ellipsoids 43 -Hisarcıklıoğlu 43 DIGIMAX 43 scf ton 43 Tl 42 cited krypton strontium 42 linearly polarized 42 Gething Formation 42 thicknesses ranging 42 Fig. 4a 42 ohm cm 42 pounds U#O# 42 drainable porosity 42 -Revolutionary Girl Utena 42 Villeta U sand 42 #.#oz t [001] 42 Mt@#.# g t Au [002] 42 Osisko Intersects 42 variograms 42 +# deg [002] 42 λ 42 Suarez Fm 42 mega pixel sensor 42 T# R# 42 fig. S2 42 Cristo de los 42 g t uncut 42 rpm SUSE LINUX 42 polygonal method 42 Electrolytic Manganese Metal 42 #.#m #.#m [003] 42 #.#ft [001] 42 m grading #.#g 42 electron doped 42 meters grading 42 titanium oxide TiO2 42 cu. 42 #-#,# mm 42 Length m 42 Ordinary kriging 42 + -1 42 Fig. 3B 42 Grade interpolation 42 polymictic conglomerate 42 dipole moment 42 mrad 42 Tonnes Cu 42 Au eqv oz 42 Å -1 42 coal seam thickness 42 #.#gpt Au [002] 42 Measured Resource 42 horizontal lateral 42 bo d 42 quartz vein -TREASURE QUEST 42 #.#M ounces 42 #.#g t Pd 42 Bluesky horizontal 41 #.#-#.# m [002] 41 Veladero mines 41 ± #.#dB 41 undrilled locations 41 η 41 geostatistical analysis 41 FDG uptake 41 airborne geophysics geological mapping 41 Pallancata Mine 41 Cardium wells 41 kΩ 41 - -winger Colby Armstrong 41 centistokes 41 MMCFED 41 magnetic permeability 41 ozs Au 41 #.#g Au t [004] 41 Cu Equiv 41 tonnes grading #.#g t [002] 41 -Joel bro Benji 41 Gold Equivalent Ounces 41 uranium eU#O# 41 gt Au 41 #.#-#.# [011] 41 underwriters overallotment 41 Inverse Distance 41 x #.#cm [001] 41 Valeura 41 cm -2 41 TW Incl 41 FeO 41 Figure 1C 41 pin TDFN package 41 psia 41 #.#g t Pt 41 INTERSECTS 41 metreage 41 Fig. 2c 41 gpt Au 41 Raman spectra 41 Aappaluttoq ruby 41 g t Niobium 41 UTM coordinates 41 GZK 40 dB insertion loss 40 h g 40 Haynesville Shale wells 40 fullyear outturn represents 40 #.#m #.#m #.#m [003] 40 Ag Eq oz 40 tonnes@#.# g t [001] 40 Maintain Outperform rating 40 ounces AuEq 40 -pass code SHOPNBC 40 arcseconds 40 #.#mx [002] 40 HREO + Y#O# 40 EUR CHF Classical 40 Acanthamoeba keratitis occur 40 titanium oxide TiO 40 g cm 40 ms -1 40 plus yttrium 40 creatine kinase MB 40 Lim x hfrs 40 meter Piz Vatgira 40 lbs eU#O# 40 τ 40 radiative cooling 40 Figure 1A 40 #-#,# ounces 40 Itiyok #-# Well 40 Crevier Minerals Inc. 40 Figure 4a 40 Michelson interferometer 40 attenuation coefficient 40 DPIIP 40 nine containerboard mills 40 #.#g t silver [001] 40 T# #C 40 hole RL# 40 -Adamske 40 holes BR# 40 gr t Au 40 illuminance 40 gpt gold 40 Recoverable reserves 40 timeshift repeat 40 #Â ° [002] 40 Dodsland area 40 Ormet employs 40 #.#g Au t [001] 39 using ordinary kriging 39 -NTRA Thoroughbred Poll 39 Schefferville Properties 39 dipolar 39 - -Schlater 39 backscattered electron