Novel and sometimes

unappreciated applications of

Geophysics and other information

sources to assist in exploration,

mine planning and management

within the economics of the project Simon Bate, AEGIS Instruments (Pty) Ltd

Lobatse, Botswana

CDM Mining Summit, Cape Town, 2014

Geologists, geophysicists, and engineers

working with a single, shared, consistent

model of the earth

geologist

•rock type

•alteration

•ore vs. waste

•grade

•geometry

geophysicist

•conductivity

•magnetism

•density

•seismic velocity

•geometry

engineer

•UCS, stress

•rock quality

•faults / shears

•soft / brittle

•geometry

Factors affecting choice of work to be completed

Regional, brown fields or deposit / mine specific

Target dimensions, physical property contrasts

and target depth and distance locations from survey

Geological or cultural “noise” and access limitations

Physical survey to be airborne, surface, borehole or in-mine

Review of historical data available- geological data

- geophysical data

- physical property data

Can re-evaluation of historical geophysical data contribute?

Detailed Target Specific Geophysics

highly dependent on Data Density

Any given geophysical technique and survey

configuration should not be promoted as a

standalone “black box” solution to all

“Target Generation” requirements for any given

target commodity in all geological environments.

Survey parameters used and density of data

points recorded relative to the target size

are generally key factors in achieving

a higher rate of successful projects

Alluvial Diamond Targeting under Calcrete Cover

Exploration

Target

Generation

Regional Geophysical Studies

Satellite Imagery – various sources, some free of charge

Airborne Geophysical Surveys, including

- aeromagnetic

- radiometric

- electromagnetic

- gravity

Airborne Hyperspectral Surveys

Regional ground coverage

The applicability of these data options to the target generation

requirements is dependent on several factors, including:

- date and time of year survey completed

- weather conditions at time of survey

- type of region

- survey specifications, data density and data quality

BOTSWANA LAND GRAVITY COVERAGE

Imaged results Density of data coverage

AIRBORNE MAGNETIC COVERAGE

Removal of high-frequency noise from aeromagnetic data

– the Botswana Dyke Swarm, NE Botswana

CASE HISTORIES

• COAL – Site in southern Africa

– Suitability for underground longwall mining

• DIAMONDS – De Beers Consolidated Mines Ltd

– Finsch Mine mining studies

• DIAMONDS - Debswana Diamond Mining Co.

– Jwaneng Resource Extension Project

• BASE & PRECIOUS METALS – African Copper plc

– Dukwe Mine: Copper and Silver

• BASE METALS – Tati Nickel Mining Co.

– Selkirk Mine: Nickel, PGE, Copper

CASE HISTORY

• COAL – Site in southern Africa

– Suitability for underground longwall mining

High Resolution Reflection Seismics

OBJECTIVES

• General known geology – Unconsolidated top layer of sand - unknown thickness

– Karoo sandstones & mudstones - ~ surface to 200-300m depth

– Coal sequence - ~ 70m thickness

– Karoo sandstones & mudstones - from 270-370m depth onwards

• Map top and bottom, if possible, of coal layers

• Map vertical movement of coal layers about normal

structures to accuracy of 10m or better

75g dynamite VIBSIST-1000

Comparison of quality of source signal

Line A: Stacked Data

500 ms

400 ms

300 ms

200 ms

100 ms

0 ms

Line A: Migrated Data

500 ms

400 ms

300 ms

200 ms

100 ms

0 ms

Line A: Detail of Migrated Data

459 m

408 m

306 m

255 m

357 m

CONCLUSIONS

• Successfully mapped top of coal at depths of

300m and more

• Mapped individual coal layers within the coal

sequence

• Mapped vertical movement about normal faults to

accuracies of better than 10m – estimated 7m

resolution or better

CASE HISTORY

•DIAMONDS – Finsch Mine, South Africa

- mapping kimberlite contacts, internal

structure and determining kimberlite volumes

in an underground mining environment

High Resolution Reflection Seismics

Images from Kimberlite Delineation by Seismic Side-Scans from Boreholes

by Cosma, Wolmarans & Enescu. EAGE Spain 2005

Borehole survey locations at precursor

on the left and main pipe on the right.

Single-hole migrated profile obtained

from borehole 65-232 and interpreted

reflector elements overlaid onto the

Block 5 main pipe model (yellow).

Cross-hole migrated profile obtained from

boreholes 65-219 and 65-220 and

interpreted reflector elements overlaid

onto the Block 5 precursor (blue)

and main pipe model (yellow).

CONCLUSIONS

• Maps geological contacts at distances of 150m and

more from the boreholes

• Maps major internal structural events

• Increased level of confidence in geological model

• Indicated potential for use in determining kimberlite

volumes with more accuracy

• Indicated potential for reducing risk in resource

estimation

• Able to complete the survey in a working mine

environment

CASE HISTORY

• DIAMONDS – Debswana Diamond Mining Co.

– Jwaneng Resource Extension Project

Titan24 MT Distributed Array

Wireline Logging

High Resolution Surface Seismic

OBJECTIVES

• Map individual kimberlite bodies to depths of 1000m or

more below surface

• Map the locations of the kimberlites to accuracies of 25m

or less for geological and volume modelling

• Map the individual facies within the kimberlite if possible

• Map the host lithologies and structural events

• Define the physical parameters for host rocks and

kimberlites with wireline logging to assist Titan24

interpretation, kimberlite facies delineation and derivation

of geotechnical parameters

• Geotechnical & engineering studies for the suitability of a

possible site for the development of an underground shaft

GOCAD Model + Constrained Titan

2D MT Resistivity Inversion

conductive resistive

Jwaneng Mine

Survey Layout

Result Analysis: 2D from 1D start

Centre Pipe

NE SW

Fault D

Fault B

Correlation ?

?

Dole

rite

dyke

Line 1

Modelled

QVK

Additional

QVK

Section of the South pipe

where the multivariate

classification appears to

show a zone of QVK

misclassified during

visual logging

ATV Image

0° 0°180°90° 270°

Breakout Travel Time

0° 0°180°90° 270°

ATV Structure

0° 0°180°90° 270°

Core Scanned ImageCross Section Log

1000 1500

Break Out AnalysisDepth

1m:15m

0°

270° 90°

180°

0°

270° 90°

180°

0°

270° 90°

180°

Bore Hole Break out Analysis

(a) (b) (c)

Waste Percentage

Calculation

(a) Interval

Kimberlite Volume

(b) Interval

Dolomite Volume

(c) Interval

Kimberlite/Dolomite

Volume

High Resolution Seismic Survey

• equipment used same as for coal site studies in

South Africa

• used radio link technology to record signals

from geophones either side of the

inaccessible area around the mine site

• recorded on 2 or 3 lines while source used

along one line only for 2.5D coverage

• recorded data from all shot sites on hydrophone

in deep hole beneath proposed site. This

allowed the data to be processed to produce

a “poor man’s” 3D dataset

Migrated 3D in line profiles, courtesy of Cameco Inc

The Millenium Uranium Project, Saskatchewan

3D surface & 3D VSP in line profiles, courtesy of Cameco Inc

The Millenium Uranium Project, Saskatchewan

CONCLUSIONS

• Lithologies and structure mapped to 1000m

• Constrained inversions map kimberlite form

• Constrained inversions map breccia zones and general

outline of individual facies

• Wireline data assists in kimberlite facies discrimination,

breccia discrimination and geotechnical evaluation

• Wireline data provides much greater detail for logging core

and subtle variations in lithology

• The high resolution seismic surveys confirmed the

Geotechnical Department conclusions, released at the same

time, that the proposed shaft site was not a viable option

CASE HISTORY

• BASE & PRECIOUS METALS – African Copper plc

– Dukwe Mine: Copper and Silver

Titan24 DCIP and MT Distributed Array

Far North

Exploration

2 km

Landsat and Local Geology

Erasmus

Winze

OBJECTIVES

• Define the geophysical signatures of the known

Dukwe mineralised horizon – drill tested over a

2km strike length and to a vertical depth of 500m

• Map the downdip and along strike extent of the

known mineralised horizon to define potential for

additional economic copper/silver ore within the

Mining Lease

• Identify other targets for potential “blind”

copper/silver mineralisation

Resistivity

IP

MT

500 m

500 m

1000 m

Titan 24

unconstrained

inversion

results from

survey line over

Dukwe deposit -

pit area

Titan24: 100m Depth of Investigation - Dukwe

DCIP

Resistivity

MT

Titan24: 250m Depth of Investigation - Dukwe

DCIP

Resistivity

MT

DCIP

Resistivity

MT

Titan24: Detailed view at 100m Depth - Dukwe

Selected Drill Results

from TITAN lines to 350m south of pit limits

Inclined drill holes- (close to true width)

1.30% Cu and 6 g/t Ag over 15.5m

1.18% Cu and 6.2 g/t Ag over 37.1m

Sub-vertical in-fill drilling – (not true width)

2.23% Cu and 23.6 g/t Ag over 116.5m

1.38% Cu and 6.5 g/t Ag over 112.8m

African Copper Press Release 06 June 2007

CONCLUSIONS

• Resistivity and MT data accurately mapped the known oxide and sulphide zones of the deposit

• Resistivity and MT data mapped along strike extensions to the drill defined mineralisation

• MT data mapped downdip extensions of the deposit

• DCIP and MT data mapped additional “blind” targets

• MT data mapped lithologies, structure and potential mineralised targets to depths in excess of 1000m

• DCIP and MT data successfully sterilised sections of the project area, to focus future exploration for faster evaluation and delineation of additional ore reserves

CASE HISTORY

• BASE METALS – Tati Nickel Mining Co.

– Selkirk Mine: Nickel, PGE, Copper

Titan24 DCIP Distributed Array

Borehole Electromagnetics

Regional Geology of the Phoenix

and Selkirk Mines Areas

HISTORICAL GEOLOGICAL MODEL

Selkirk Massive Sulphide

in Metagabbros

Barren cummulate gabbro

Granites

OBJECTIVES

• Confirm or refute new geological model of host

mineralised metagabbros extending to the

southern margin of the Selkirk Mining Lease

• Determine the electrical and polarisable signature

of the remains of the Selkirk Massive Sulphide

Deposit and surrounding disseminated

mineralisation

• Delineate additional blind targets, with similar

geophysical signatures, close to Selkirk

Selkirk Mine – Titan24 Down Plunge

Selkirk Orebody DSLK003

DSLK002

CONFIRMATION OF NEW

GEOLOGICAL MODEL

DSLK002

– Semi-massive basal mineralisation with later quartz veining

FROM TO LENGTH (m) Ni Cu Au Pd Pt

212.17 215.64 3.47 0.49 0.85 11.34 1.26 0.22

DSLK003

– Massive sulphide bounded by coarse blebby disseminated sulphide with localized massive bands

FROM TO LENGTH Ni Cu Pt Pd Au

482.04 483.46 1.42 2.79 2.21 0.15 2.90 0.15

Selkirk Mine – Down Plunge

DSLK002 – at southern margin of previous drilling

- Quartz veined basal contact mineralisation

3.47m of 11.34 g/t Au

DSLK003 – down plunge from previous drilling

- a 57m package of disseminated and semi-massive sulphides averaging 0.35% Ni and 0.47% Cu

- including 1.42m of massive sulphide

grading 2.79% Ni and 2.21% Cu

Selkirk Mine – DSLK003

Central Tx Loop 300x300m

CONCLUSIONS

• New stratigraphic model confirmed

• Titan24 DCIP investigated to depths of 500-600m

• Down plunge extent of Selkirk mineralised horizon

extended from 700m to 1500m

• Discrete low resistivity, high chargeability targets

confirmed to reflect significant Ni, Cu & PGE

mineralisation of similar grades and widths

• Intention of development of Selkirk Mine as an open pit

operation supported by knowledge of down plunge

potential for future possible underground operation

The Voorspoed Site Length: 389.6m

Vert.: 44m

The Voorspoed Site

The Voorspoed Site Curvatures:

1. Vert. – 0.3° /m

2. Hor. – 1.1° /m

3. Hor. – 2.0° /m

The Voorspoed Site

Zone of Magnetic Interference

PLAN VIEW

19

45

0 E

19

45

0 E

19

50

0 E

19

50

0 E

19

55

0 E

19

55

0 E

19

60

0 E

19

60

0 E

19

65

0 E

19

65

0 E

19

70

0 E

19

70

0 E

19

75

0 E

19

75

0 E

19

80

0 E

19

80

0 E

19

85

0 E

19

85

0 E

32100 S 32100 S

32050 S 32050 S

32000 S 32000 S

31950 S 31950 S

31900 S 31900 S

31850 S 31850 S

Gyro_In

Gyro_Out

Optical_In

Optical_Out

EMS1_In

EMS1_Out

EMS4

EMS3_In

EMS3_OutEMS2_In

EMS2_Out

Benchmark Study: Results (Azimuth 2)

50m

PLAN VIEW

Small deviations

due to mag effects

At cost varying from 0.5% to

3% of the cost of drilling;

Which survey would you

prefer?

Who is accountable?

DMT CoreScan®3

high-tech core logging tool DMT CoreScan3 is a portable core imaging device

developed for drill core image acquisition, storage

and evaluation of full and slabbed core.

Furthermore, whole core boxes can be scanned in

one image.

Full core is rotated 360°around its cylindrical axis

while the line-scan camera, positioned parallel to

the axis of rotation, scans its surface. Full core is

scanned at a rate of ~20 sec/m and the image can be

stored as BMP, PNG, TIF or JPG files.

DMT CoreScan3 - optical drill-core acquisition and storage unit (stand-

alone)

“360°Full Core Mode“ Scanning during rotation of the core

"unrolled" image of the core mantle

5 pixel / mm

360°

“Plane Mode“ Scanning of slabbed core and core boxes

Resolution: 5 – 40 pixel/mm

Surface image of the slabbed core

CoreStructure AnalysisTM Structural Analysis

Software system for quantitative structural

evaluation, analysis and presentation

Geological structures are evaluated by pickup

routines (bedding, foliation, joints, faults, veins,

self-determined)

Acquired structures can be N-oriented in connection

with geophysical logs or oriented drill cores

Geomechanical parameters: RQD, FD, FS

The orientation of the borehole together with the structures are presented graphically and in the case

of deviated boreholes, the dip direction and dip of

the structures are corrected directly on request

CoreStructure AnalysisTM

Quantitative Statistics