ground penetrating radar (gpr) -...

Ground Penetrating RadarGround Penetrating Radar

(GPR)(GPR)In the search for uraniferousIn the search for uraniferous

paleopaleo--channelschannels

Klaus – P. [email protected]

Uranium Conference 23 - 24 October 2009, Swakopmund, Namibia

EARTHMAPS CONSULTING

Some GPR Principles

Source: Sensors & Software Inc.

GPR Signal is sensitive to changes in:

• electrical conductivity σ• dielectric permittivity ε•(magnetic permeability μ)


GPR Survey Principles



GPR: Factors to considerDirect Air Wave

System Ring down

Calcrete 0.06 - 0.065

Direct Air Wave Response

RadarVelocity

Sources of Noise



GPR Survey: Antennas



Dune Survey



25 MHz

50 MHz

100 MHz

200 MHz


GPR Survey: Antennas for Paleo-channel work

25 MHz

12.5 MHz

Production Rate:

3.5 km/day

GPR Survey: Namibian Case Studies


Trekkopje

Langer Heinrich

Tumas

EPL 3516


EPL 3516 - Pitchstone Exploration Ltd.

GPR

-

Acknowledgements: Pitchstone Exploration Ltd.Acknowledgements: Pitchstone Exploration Ltd.

Terrain:

Gypcrete & Calcrete


Horizontal Loop Electromagnetic (HLEM) Test Survey: 50 m coil spacing

Line CD - EPL 3516

S N10/8/2009

C D

Pitchstone Exploration Ltd.

Figure 6bedrock

DN09-25 DN09-26 DN09-27 DN09-28

EPL 3516 - Pitchstone Exploration Ltd.

Terrain:

Gypcrete & Calcrete

HLEM

+

Acknowledgements: Pitchstone Exploration Ltd.Acknowledgements: Pitchstone Exploration Ltd.



Trekkopje

Langer Heinrich

Tumas

EPL 3516

Acknowledgements: Areva Resources NamibiaAcknowledgements: Areva Resources Namibia


Trekkopje Mine

Terrain:

Gypcrete & Calcrete



Trekkopje Mine

Terrain:

Gypcrete & Calcrete

GPR

-

Trekkopje paleo-channel

Horizontal Loop Electromagnetic (HLEM) Test Survey: 50m coil spacing Line CD - Klein Trekkopje

SE NW3/9/2009

C D8K

TH00

62

KTR

C 1

415

KTR

C 0

125

KTP

C 3

-606

UranMin (Namibia) Pty Ltd

KTP

C15

200-

0000

n

bedrockFigure 5



Trekkopje Mine

Terrain:

Gypcrete & Calcrete

HLEM

+

Trekkopje paleo-channel



Trekkopje

Langer Heinrich

Tumas

EPL 3516

Acknowledgements: Reptile Uranium Namibia (Pty) LtdAcknowledgements: Reptile Uranium Namibia (Pty) Ltd


520000

520000

7450

000

7450

000

0 0.5 1 1.5 20.25

Kilometers

LegendGPR Test Line 1A-1B

GPR Test Line 2A-2B

GPR Test Line AB

GPR Test Line CD

Reptile Uranium Namibia (Pty) LtdGround Penetrating Radar Test Survey -

Locality Map

Earthmaps Consulting May 2008 WGS84 UTM33S

2B

2A

1B

1A

Tumas paleo-channel

Tu

ma

s R i v e r

Tumas Project

Terrain:

Calcrete&

Alluvium

Line 2

Line 2



Tumas Project

Terrain:

CalcretePaleo-channel

GPR

+

Tumas paleo-channel



Tumas Project

Terrain:

CalcretePaleo-channel

GPR

+

Line 2

Tumas paleo-channel



520000

520000

7450

000

7450

000

0 0.5 1 1.5 20.25

Kilometers

LegendGPR Test Line 1A-1B

GPR Test Line 2A-2B

GPR Test Line AB

GPR Test Line CD

Reptile Uranium Namibia (Pty) LtdGround Penetrating Radar Test Survey -

Locality Map

Earthmaps Consulting May 2008 WGS84 UTM33S

2B

2A

1B

1A

Tumas paleo-channel

Tu

ma

s R i v e r

Tumas Project

Terrain:

ActiveRiver

Drainage

Line 1

Line 1



Tumas Project

Terrain:

ActiveRiver

Drainage

GPR

+

Line 1 - S

Tumas active drainage



Tumas Project

Terrain:

ActiveRiver

Drainage

GPR

+

Line 1 - N

Tumas active drainage



Trekkopje

Langer Heinrich

Tumas

EPL 3516

Acknowledgements: Langer Heinrich Uranium (Pty) LtdAcknowledgements: Langer Heinrich Uranium (Pty) Ltd


Langer Heinrich Mine Terrain:

Calcrete&

Alluvium

Langer Heinrich Mine



Terrain:

Calcrete&

Alluvium


GPR

+ -

Traverse 1

Langer Heinrich paleo-channel



Traverse 1

Terrain:

Calcrete&

Alluvium


HLEM

+ -faulted bedrock




Langer Heinrich Mine Terrain:

Calcrete&

Alluvium




Traverse 2

Terrain:

Calcrete&

Alluvium


GPR

+




Traverse 2

Terrain:

Calcrete&

Alluvium


HLEM

-



GPR & HLEM: Comparison

++-- 4 m depth 4 m depth resolution to +resolution to +-- 25 25 m m provided provided resistivity not < 1 resistivity not < 1 ohm.mohm.m

++-- 2 m depth 2 m depth resolution down to resolution down to ++--5 m5 m

GypcreteGypcrete,,CalcreteCalcrete< 10 ohm. m< 10 ohm. m

++-- 4 m depth 4 m depth resolution to +resolution to +-- 35 35 mm provided provided resistivity not > 30 resistivity not > 30 ohm.mohm.m

++--2m depth 2m depth resolution down to resolution down to ++-- 25 m 25 m

Calcrete, Calcrete, AlluviumAlluvium>10 ohm.m>10 ohm.m

HLEM (50m coil)HLEM (50m coil)GPR (12.5 MHz)GPR (12.5 MHz)EnvironmentEnvironment

Colour Key:Good resolution & penetrationPoor resolution & poor penetration


GPR & HLEM: Comparison

0.1 1 10 100 1000

Resistivity: ohm.m

HLEM

GPR Langer Heinrich

(Tum

as)

Trekkopje

EP

L 3516

Not effective Effective

GPR Survey: Namibian Case Study: Results


Trekkopje

Langer Heinrich

Tumas

EPL 3516

GPR penetration: +GPR penetration: +-- 25 m 25 m in calcretised alluviumin calcretised alluvium

GPR penetration: +GPR penetration: +-- 5 m 5 m in cypcretesin cypcretes

‘‘Where you penetrateWhere you penetratethe resolutionthe resolution

is hard to beat.is hard to beat.’’

Acknowledgements: Swakop Uranium (Pty) LtdAcknowledgements: Swakop Uranium (Pty) Ltd


GPR: Other Applications

Groundwater Table

Acknowledgements: Sam Nujoma Marine and Coastal Research CentreAcknowledgements: Sam Nujoma Marine and Coastal Research Centre



Salt WaterVs.

Fresh Water

(Omaruru River

Mouth)

sea Omaruru River

beach

Saline water – fresh waterInterface

Acknowledgements: Knight Piesold (Pty) LtdAcknowledgements: Knight Piesold (Pty) Ltd



Pipe PipePipe

Pipe

Acknowledgements: Gem Diamonds Mining Company of AfricaAcknowledgements: Gem Diamonds Mining Company of Africa


GPR: Other Applications DiamondiferousGravels in

Kasai & LongatshimoRivers

(DRC)



GPR: Other ApplicationsDiamondiferous

Gravels inKasai & Longatshimo

Rivers

(DRC)




DiamondiferousGravels inKasai &

LongatshimoRivers

(DRC)

Gravel bars




K a s a i R i v e r

Gravel bars





LongatshimoRivers

(DRC)

Gravel bar





LongatshimoRivers

(DRC)Gravel bars

Boulders


Thank YouThank You

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