modern exploration methods - deutsche rohstoffagentur
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Modern exploration methods Modern exploration methods --locating hidden goldlocating hidden goldlocating hidden gold locating hidden gold
paleochannels in the Cariboo paleochannels in the Cariboo Mining District BC CanadaMining District BC CanadaMining District, BC, Canada. Mining District, BC, Canada.
W k hW k h O t iti i C d ’ R S t dO t iti i C d ’ R S t dWorkshop Workshop –– Opportunities in Canada’s Resource Sector and Opportunities in Canada’s Resource Sector and Different Financing Instruments for Mining ProjectsDifferent Financing Instruments for Mining Projects
Embassy of Canada to GermanyEmbassy of Canada to Germany1111thth and 12and 12thth December 2013December 2013
D. EberleD. Eberle1,21,2, D. Bastian, D. Bastian1,21,2, N. Ebel, N. Ebel11 , M. Pein, M. Pein11,J. Wallisch,J. Wallisch11 and and R. SchwarzR. Schwarz11
11 geotec Rohstoffe, Berlin, Germany, [email protected] Rohstoffe, Berlin, Germany, [email protected] Berlin Technical University, GermanyBerlin Technical University, Germany
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Outline/PreviewOutline/Preview
•• Geology of placer gold in the Geology of placer gold in the CCaribooariboo gold mining districtgold mining district
•• SkyTEM applied over the Mary Creek, Toop and Beaver Pass concessionsSkyTEM applied over the Mary Creek, Toop and Beaver Pass concessions
•• Ground geophysics applied on selected buried targetGround geophysics applied on selected buried target 2D R i i i2D R i i i 2D Resistivity2D Resistivity Refraction Refraction SeismicsSeismics
•• Drilling a conductive buried channel featureDrilling a conductive buried channel feature•• Drilling a conductive buried channel featureDrilling a conductive buried channel feature
•• Discussion of results and conclusionsDiscussion of results and conclusions
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NN
20 km
Regional geology showing survey areasRegional geology showing survey areasRegional geology showing survey areasRegional geology showing survey areas((GeoSciGeoSci BC Geology Map, 2010)BC Geology Map, 2010)
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Two types ofTwo types of glaciolacustrineglaciolacustrine deposit sedimentsdeposit sedimentsTwo types of Two types of glaciolacustrineglaciolacustrine deposit sedimentsdeposit sediments(James and (James and DalrympleDalrymple, 2012), 2012)
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Schematic of buried placer deposit settings.Schematic of buried placer deposit settings.Schematic of buried placer deposit settings.Schematic of buried placer deposit settings.((LevsonLevson and Giles, 1995)and Giles, 1995)
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geotecData AcquisitionData Acquisition
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Line direction W Line direction W –– EESpacing 50 mSpacing 50 mTie line direction N Tie line direction N –– SSSpacing 500mSpacing 500m
Nominal terrain Nominal terrain cclearance of learance of system 30 m system 30 m Flight speed 40Flight speed 40 80 km/h80 km/hFlight speed 40 Flight speed 40 –– 80 km/h 80 km/h
Transmitter area 314 mTransmitter area 314 m22Transmitter area 314 mTransmitter area 314 m22
•• TxTx LLow Momentow MomentRepetition Frequency 210 HzRepetition Frequency 210 HzPeak Moment ca 3300 NIAPeak Moment ca 3300 NIAPeak Moment ca. 3300 NIAPeak Moment ca. 3300 NIA
•• TxTx High MomentHigh MomentPeak Moment ca.145 000 NIAPeak Moment ca.145 000 NIARepetition Frequency 22.5 HzRepetition Frequency 22.5 Hz
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Repetition Frequency 22.5 HzRepetition Frequency 22.5 Hz
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Generator Generator •• flying 10 m beneath the helicopterflying 10 m beneath the helicopter•• powering the TDEM powering the TDEM systemsystem
MMag sensorag sensorReadings at 45 Hz are taken in betweenReadings at 45 Hz are taken in betweenReadings at 45 Hz are taken in betweenReadings at 45 Hz are taken in between
each HM pulseeach HM pulse
DGPS sensors on frame and base stationDGPS sensors on frame and base station
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Mary Creek magnetic and conductivity survey dataMary Creek magnetic and conductivity survey dataMary Creek magnetic and conductivity survey dataMary Creek magnetic and conductivity survey data
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Conductivity at 5 m and 15 m below surfaceConductivity at 5 m and 15 m below surface
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Conductivity at 30 m and 60 m below surfaceConductivity at 30 m and 60 m below surfaceyy
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Z: 445 – 1020 mY: 5880170 – 5881010 mX: 560990 563510 mX: 560990 – 563510 mCell size: 20x20x10m3
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DC 2D resistivityDC 2D resistivity DC 2D resistivityDC 2D resistivityDC 2D resistivityDC 2D resistivityRS Refraction seismicRS Refraction seismicRC Reverse RC Reverse
DC 2D resistivityDC 2D resistivityRS Refraction seismicRS Refraction seismicRC Reverse RC Reverse
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Lippmann IP and Earth Lippmann IP and Earth RResistivity esistivity MMeter combined with stainless eter combined with stainless electrodes manufactured by geoanalysis.deelectrodes manufactured by geoanalysis.de
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2D resistivity section with 5 m electrode spacing2D resistivity section with 5 m electrode spacing
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2D resistivity sections with 5 m electrode spacing2D resistivity sections with 5 m electrode spacing
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Mean thickness of glacial Mean thickness of glacial sediments betweensediments between40 and 60 m40 and 60 m40 and 60 m40 and 60 m
Refraction Refraction seismicsseismics
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Vertical lithology section along conductive channel fill Vertical lithology section along conductive channel fill constructed from borehole logsconstructed from borehole logsconstructed from borehole logsconstructed from borehole logs
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SynopsisSynopsis
Method Depth to bedrock2D resistivity Near-surface resistive layer of 25 -
y py p
2D resistivity Near-surface resistive layer of 25 -30 m thickness underlain by good conductor, bottom of which was not recognisedrecognised
SkyTEM Conductor in depth interval 15 – 35 m. Depth to resistive bedrock ca. 40 m40 m.
Refraction seismics 60 – 80 m (3000 - 3500 m/s)Drilling 40 - 45 mg
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geotec3D Model all measured data (3D Model all measured data (GeoviaGeovia Surpac Software)Surpac Software)
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Pattern of buried highPattern of buried high--level channelslevel channelsgg
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Glacial moraineGlacial moraineoror
dried channel?dried channel?dried channel?dried channel?
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DC 2D ResistivityDC 2D ResistivityDC 2D ResistivityDC 2D Resistivity
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2D resistivity 2D resistivity sectionssectionssections sections traversingtraversingupup--hill channelshill channels
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ConclusionsConclusions•• SkyTEMSkyTEM survey data prove useful in the exploration of highsurvey data prove useful in the exploration of high--level level
buried channels in the buried channels in the CaribooCariboo gold districtgold district
•• Drilling hit conductive channel fill in depth of burial Drilling hit conductive channel fill in depth of burial predicted by 3D conductivity voxelpredicted by 3D conductivity voxel
•• Channel fill is supposed to contain increased contents of Channel fill is supposed to contain increased contents of heavy minerals, e.g. magnetite, as follows from heavy minerals, e.g. magnetite, as follows from Analytical Signal transform of the airborne magnetic fieldAnalytical Signal transform of the airborne magnetic field
•• Results from ground geophysical data (2D multiResults from ground geophysical data (2D multi--electrode resistivityelectrode resistivityand refraction and refraction seismicsseismics) are inclusive) are inclusive
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AcknowledgementAcknowledgement
The authors want to express their gratitude to The authors want to express their gratitude to •• Henning Gold Mines Inc., Vancouver, BC, Canada Henning Gold Mines Inc., Vancouver, BC, Canada
C G G & C G GC G G & C G G•• Canada Gold Trust GmbH & Co. KG, Konstanz, GermanyCanada Gold Trust GmbH & Co. KG, Konstanz, Germanyfor granting access to data and permission to publish.for granting access to data and permission to publish.
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Thank you very muchThank you very muchThank you very muchThank you very muchfor your attention!for your attention!o you atte t oo you atte t o
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ReferencesReferencesJ N P dJ N P d D lD l R W (2012)R W (2012) F iF i M d lM d l GEOt tGEOt t 6 G l i l6 G l i l James, N.P. and James, N.P. and DalrympeDalrympe. R.W., (2012), . R.W., (2012), FaciesFacies Models, Models, GEOtextGEOtext 6, Geological 6, Geological Association of Canada. Association of Canada.
KnödelKnödel, K., Lange, G., Voigt, H., K., Lange, G., Voigt, H.--J.,(Ed.) ,(2007), Environmental Geology. Handbook of J.,(Ed.) ,(2007), Environmental Geology. Handbook of Field Methods and Case Studies, Field Methods and Case Studies, Springer, Berlin, Heidelberg, New York.Springer, Berlin, Heidelberg, New York.Levson Victor M and Giles Timothy R (1995): BuriedLevson Victor M and Giles Timothy R (1995): Buried Channel Placers in SelectedChannel Placers in Selected Levson, Victor M. and Giles, Timothy R. (1995): BuriedLevson, Victor M. and Giles, Timothy R. (1995): Buried--Channel Placers, in Selected Channel Placers, in Selected British Columbia Mineral Deposit Profiles, Volume 1 British Columbia Mineral Deposit Profiles, Volume 1 -- MetallicsMetallics and Coal, and Coal, LefebureLefebure, , D.V. and Ray, G.E., Editors, British Columbia Ministry o Energy and Mines, Open File D.V. and Ray, G.E., Editors, British Columbia Ministry o Energy and Mines, Open File 19951995--20, pages 2520, pages 25--28. 28.
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