dgc 12-03-06 pdac grade control

Grade Control &

Dilution Management Detour Lake Open Pit Gold Mine

PDAC Technical Sessions

March 6, 2012

© 2011 Detour Gold All Rights Reserved. 2

This presentation contains certain forward-looking information as defined in applicable securities laws (referred to herein as “forward-

looking statements”). Specifically, this presentation contains forward-looking statements regarding the reserve and resource

estimates, ore grade, expected mine life, anticipated gold production, gold recovery, cash operating costs and other costs, capital

costs, sensitivity to metal prices and other sensitivities, financial analysis of the project, commencement of operations, potential

expansion opportunities, plans for organic growth and expected drilling activities. Forward-looking statements involve known and

unknown risks, uncertainties and other factors which are beyond Detour Gold’s ability to predict or control and may cause Detour

Gold’s actual results, performance or achievements to be materially different from any of its future results, performance or

achievements expressed or implied by forward-looking statements. These risks, uncertainties and other factors include, but are not

limited to, gold price volatility, changes in debt and equity markets, the uncertainties involved in interpreting geological data,

increases in costs, environmental compliance and changes in environmental legislation and regulation, interest rate and exchange

rate fluctuations, general economic conditions and other risks involved in the gold exploration and development industry, as well as

those risk factors discussed in the section entitled “Risk Factors” in Detour Gold’s February 7, 2012 short form prospectus and in the

continuous disclosure documents filed by Detour Gold on and available on SEDAR at www.sedar.com. Such forward-looking

statements are also based on a number of assumptions which may prove to be incorrect, including, but not limited to, assumptions

about the following: the supply and demand for gold, and the level and volatility of the price of gold; the availability of financing for

exploration and development activities; the estimated timeline for the development of the Detour Lake gold project; the expected

mine life; anticipated gold production; gold recovery; the development schedule; cash operating costs and other costs; the financial

analysis for the project; capital costs; sensitivity to metal prices and other sensitivities; the accuracy of reserve and resource

estimates and the assumptions on which the reserve and resource estimates are based; the receipt of necessary permits; market

competition; ongoing relations with employees and impacted communities; and general business and economic conditions.

Accordingly, readers should not place undue reliance on forward-looking statements. The forward-looking statements contained

herein are made as of the date hereof, or such other date or dates specified in such statements. Detour Gold undertakes no

obligation to update publicly or otherwise revise any forward-looking statements contained herein whether as a result of new

information or future events or otherwise, except as may be required by law. If the Company does update one or more forward-

looking statements, no inference should be drawn that it will make additional updates with respect to those or other forward-looking

statements.

Forward Looking Information


Information Concerning Estimates of Mineral Reserves and Resources

The mineral reserve and resource estimates reported in this presentation were prepared in accordance with Canadian National

Instrument 43-101Standards of Disclosure for Mineral Projects (“NI 43-101”), as required by Canadian securities regulatory

authorities. For United States reporting purposes, the United States Securities and Exchange Commission (“SEC”) applies different

standards in order to classify mineralization as a reserve. In particular, while the terms “measured,” “indicated” and “inferred” mineral

resources are required pursuant to NI 43-101, the SEC does not recognize such terms. Canadian standards differ significantly from

the requirements of the SEC. Investors are cautioned not to assume that any part or all of the mineral deposits in these categories

constitute or will ever be converted into reserves. In addition, “inferred” mineral resources have a great amount of uncertainty as to

their existence and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an inferred

mineral resource will ever be upgraded to a higher category. Under Canadian securities laws, issuers must not make any disclosure

of results of an economic analysis that includes inferred mineral resources, except in rare cases.

On January 31, 2011, Detour Gold announced an updated mineral resource and reserve estimate. The following QPs participated in

this update: Michel Dagbert, Eng., Senior Geostatistician and André Laferrière, P. Geo., Senior Geologist of SGS Canada Inc.

(mineral resources); and André Allaire, Eng., Director Mining and Metals and Patrice Live, Eng., Mining Manager of BBA Inc (mineral

reserve). The NI 43-101 compliant Technical Report for this update was filed on SEDAR on March 15, 2011.

On January 25, 2012, Detour Gold announced a mineral resource and reserve update. The following QPs participated in this update:

Michel Dagbert, Eng., Senior Geostatistician of SGS Canada Inc (mineral resources) and Patrice Live, Eng., Mining Manager of BBA

Inc (mineral reserves).

NI 43-101 Disclosure


Detour Gold Corporation

Detour Lake

Acquisition of Detour Lake

completed in January 2007

Past Gold production of 1.8 M oz

from 1983-1999 (Open pit & U/G)

Over 1,000 km of drilling

completed, including >520,000 m

from Detour Gold

Open pit gold reserves of 15.6

million ounces @ US$850/oz

Estimated LOM average gold

production of 650,000 oz/yr)

Estimated mine life of +20 years


Presentation Outline

Overview of Detour Lake geology

Grade control tests using diamond drilling for reserve

validation

Grade control test using reverse circulation drilling

Mine planning and operational aspects for grade control

© 2011 Detour Gold All Rights Reserved. 6 © 2011 Detour Gold All Rights Reserved. 6

Geology Overview


Abitibi Greenstone Belt


15.6 M oz in Reserves

Detour Lake Regional Geology

Existing DDH Gold occurrence (OGS)

DDH intersection >1g/2m DDH intersection >1g/10m


Detour Lake Geology

US$850 reserve pit

15.6 M oz

SLDZ

Gold mineralization occurs in a vein field extending >3.5 km along strike, width of 200-350 m and 1 km below surface


Detour Lake Host Rocks

Geology Description

Detour Lake Upper Fm 89 Massive and pillow mafic flows, main host of the auriferous

mineralization at Detour Lake.

CMH 2

Narrow felsic volcanic unit (1-3m), strongly silicified,

mylonitized and mineralized directly at contact of the Detour

Lake Upper and Lower Formation, previously mined by Placer

Dome.

Detour Lake Lower Fm 8.5 Sequence of mafic and ultramafics (komatiitiques) flows. The

upper contact is strongly altered in talc-schlorite.

SLDZ Strongly deformed sub-vertical EW striking corridor, in contact

with Caopatina seds.

Caopatina Sediments 0.5 Assemblage characterized by a succession of laminated

siltstone, quartz wacke and mafic volcaniclastics. Very little

mineralization. S

N

% of

Mineralization


DG-07-128

177.6m

180.9m

183.6m

189.9m

191.2m

194.3m

197.1m

202.0m

207.3m

188.3m

Ma

fic

ma

ss

ive

flo

w

Ma

fic

pillo

w f

low

Alt

era

tio

n

Défo

rmati

on

2.0 g/t

0.3 g/t

6.3 g/t

1.5 g/t

0.1 g/t

0.01 g/t

0.03 g/t

0.05 g/t

0.02 g/t

0.04 g/t

Mineralized quartz veins within massive flow

Pyrrhotite and pyrite within brecciated pillow

selvages

3.0 g/t Au

Hanging Wall (Detour Lake Upper FM)


Several sub-parallel, E-W striking high strain zones associated with gold mineralization occur in HW of SLDZ

Strong potassic (biotite) alteration

SLDZ

31.2 g/t Au

Gold Mineralization


Positive Economics @ US$850/oz

>1.0 g/t Au

0.5 - 1.0 g/t Au

<0.5 g/t Au

20,600E

16,500E

700 m

Open pit

@ 0.5 g/t cut-off

As at Dec. 31, 2011

@

US$850/oz

Tonnes

(millions)

Grade

(g/t)

Contained

Gold

(‘000 oz)

Reserves (1)

Proven 101.6 1.29 4,222

Probable 368.4 0.96 11,351

P&P 470.0 1.03 15,573

Resources (2)

Measured 124.5 1.36 5,424

Indicated 554.3 1.00 17,836

M&I 678.8 1.07 23,261

Inferred 208.5 0.86 5,785

1. After a 95% mining recovery rate; Mining dilution

factor of 15.5%.

2. Inclusive of mineral reserves.


Grade Control Tests Using Diamond Drilling


Detour Lake Surface Plan

2011 year-end reserves

= 15.6 M oz

Simulated Grade Control Test Block



DD Grade Control

Test Block

20X20 m drilling block

10X10 m drilling block


40 x 40 m drilling

15 holes

Block size

10X5X10 m


Block model

shown at

elevation 6230 m


20 x 20 m drilling

52 holes

Block size

10X5X10 m

40 x 40 m drilling

15 holes

Block size

10X5X10 m


Block model

shown at

elevation 6230 m


10 x 10 m drilling

133 holes

Block size

10X5X10 m

20 x 20 m drilling

52 holes

Block size

10X5X10 m

40 x 40 m drilling

15 holes

Block size

10X5X10 m


Block model

shown at

elevation 6230 m


Grade Control

Test




40 x 40 m drilling

20 x 20 m drilling

10 x 10 m drilling

Section

19,460 E Looking West


Total (M+I+I) Resource Estimation

Test Block Tonnes Au (g/t) Contained Oz delta Oz

40x40 m 1,085,201 1.08 37,722 base case

20x20 m 1,205,706 1.01 38,976 3.3%

10x10 m 1,135,672 1.07 39,040 3.5%


Parameters used for resource estimation:

1. 0.5 g/t Au cut-off grade

2. Ordinary Kriging method

3. Dynamic Anisotropy search filters

4. Classification search:

Measured: 25m vertical, 25m E-W, 5m N-S

Indicated: 50m vertical, 50m E-W, 5m N-S


Conclusions

Contained ounces very similar (variance +4%)

Gold grade variance within 7%

Number of tonnes within acceptable range (variance up

to 11%)

40 x 40 metre drill spacing is appropriate for reserve

estimation

10x10 metre simulated grade control drill spacing tightens

the mineralized envelopes


Grade Control Tests Using Reverse Circulation Drilling


RC Grade Control Rational

Blast Hole Grade Control not practical due to vertical nature of Detour

Lake deposit

Reverse Circulation (RC) drilling using inclined holes is a better grade

control method for vertical gold deposits

RC is not yet widely used in Canada

Successful RC grade control is used at the following mines:

Open Pit Mines Location

Cowal Australia

Kalgoorlie Consolidated Gold

Mines Australia

Boddington Australia

Oyu Tolgoi Mongolia


Objectives

Confirm block model for mining

Measure penetration rate, costs and rig performance

Establish adequate drilling pattern and sampling protocol

Verify penetration rate, costs and rig performance

Train geologists and samplers

on RC drilling

Verify efficiency and turnaround

time for assay results

2011 RC Grade Control Exercise


RC Grade Control Exercise

Objectives of proposed Program

10,000 m of RC drilling covering area of 110 m (E-W) x 115 m (N-S)

319 holes averaging approx. 37 m (equivalent to two 12 m benches)

Drill hole spacing of 10 m x 5 m

Sample collected every metre (5kg /sample)

Overburden is 5 to 7 m thick

Holes inclined at -50º 30m

DD Grade Control

Test Block

RC Grade Control

Test Block


2012 proposed RCH

2012 completed RCH

10 x 5 m drilling

116 holes

4,159 m

Testing two

12 m benches)

Completed RC holes in test area


Model Comparison

Cross-section 19510E showing both models

RC GC model

FS-Reserves model


Cross-section 19410E showing both models

RC GCmodel

FS-Reserves-model

Model Comparison


2011 RC Grade Control Conclusions

2011 RC program

Limited results confirmed the gold mineralized zones in block

model

Program stopped due to extensive old scrap steel in overburden

2012 RC program underway

RC drilling in Calcite Zone to support 2012 mine plan

Expand to 2 shifts/day

Continue training

Develop grade control procedure manual


2012 RC Drilling Program

2011 year-end reserves

= 15.6 M oz

2012 RC drilling

in Starter Pit

2011 RC drilling


Mine planning and

operational aspects

for grade control


0.5 0.3 > 0.65 Au

18500E

6168 m Bench


0.5 0.3 > 0.65 Au

Calcite Zone (looking west)

150m

Cross-Section 18500 E


High Precision systems are standard technology on blasthole drills

Especially Atlas Copco ‘Pit Viper’ PV-271

Designed hole locations & geometry are sent to the drills

HP-GPS provides cm accurate hole locations

High Precision GPS Control Drills


Benefits include:

Especially Atlas Copco ‘Pit Viper’ PV-271

Much improved bench floors

Rockmass ‘characterization’ (gathers data as it drills)

Better blasting

Closer to ‘Automation’, Remote Operations

High Precision GPS Control Drills


High Precision GPS control

Drill & Blast

Engineer

Site Communications System

Operator

Display

Central Database

Server

Geologist

Mine Planner

Data Input GUI

GPS position

Drill Status &

Progress GUI

Reports

High Precision GPS System

Drill

Operator

Sensory

Devices

On-Board

Sensors

Interface

Actual data- sample

locations, hole locations,

rock hardness

Designed

hole

information


8 CAT 795F trucks at site

(2 supplied by CAT)

Supply of 73 Bridgestone tires to date

2 CAT6060 shovels assembled

Detour Lake – Initial Mining Fleet at Site

Loading Units

3 X Hydraulic CAT6060 (25 m3)

2 X Electric cable shovels (45 m3)

Haulers

23 X CAT 795F trucks (320 t);

30-35 at peak of operation


Mining Equipment (Shovel & Trucks)

Large equipment to keep unit costs

under control – ‘Benefits of Scale’

Doesn’t mean you can’t manage

dilution

Modern hydraulic excavators ‘RH340

type’ offer low risk and high control:

3 degrees of freedom: hoist, crowd

& bucket tilt

Good estimate of ore grade for

every bucket

Cable shovels ‘495 HR size’ (low cost,

high productivity) to be used effectively

in waste


Large Equipment (Shovel & Trucks)

Bench

Progression

Checks

Operator’s Screen


Typical HP-GPS Control Shovels

proximity to U/G

workings


High Precision GPS Control Shovels

HP-GPS is well

established

technology,

used worldwide

Slide shows

bench elevation

control

Will be required

for mine/mill

reconciliation


RC drilling will work at Detour Lake

RC drilling is generally backing up the diamond drilling

Ore zones are of mineable width and continuous

Dilution to be manageable

Operations challenges to be met with:

High levels of geological control

High Precision GPS on drills & loading equipment

Conclusions


Construction update: February 2012

11-11-01


CONTACT US

Andrew Croal, Director – Technical Services

[email protected]

Tel: 416.304.0800 x 2244

www.detourgold.com

dgc 12-03-06 pdac grade control

Documents

forwardlooking statements

gold exploration

price of gold

detour lake gold project

gold price volatility

detour golds ability

detour golds actual

development activities