THESE TERMS GOVERN YOUR USE OF THIS PRODUCT

Your use of this electronic information product (“EIP”), and the digital data files contained on it (the “Content”), is governed by the terms set out on this page (“Terms of Use”). By opening

the EIP and viewing the Content , you (the “User”) have accepted, and have agreed to be bound by, the Terms of Use.

EIP and Content: This EIP and Content is offered by the Province of Ontario’s Ministry of Northern Development, Mines and Forestry (MNDMF) as a public service, on an “as-is” basis. Recommendations and statements of opinions expressed are those of the author or authors and are not to be construed as statement of government policy. You are solely responsible for your use of the EIP and its Content. You should not rely on the Content for legal advice nor as authoritative in your particular circumstances. Users should verify the accuracy and applicability of any Content before acting on it. MNDMF does not guarantee, or make any warranty express or implied, that the Content is current, accurate, complete or reliable or that the EIP is free from viruses or other harmful components. MNDMF is not responsible for any damage however caused, which results, directly or indirectly, from your use of the EIP or the Content. MNDMF assumes no legal liability or responsibility for the EIP or the Content whatsoever. Links to Other Web Sites: This EIP or the Content may contain links, to Web sites that are not operated by MNDMF. Linked Web sites may not be available in French. MNDMF neither endorses nor assumes any responsibility for the safety, accuracy or availability of linked Web sites or the information contained on them. The linked Web sites, their operation and content are the responsibility of the person or entity for which they were created or maintained (the “Owner”). Both your use of a linked Web site, and your right to use or reproduce information or materials from a linked Web site, are subject to the terms of use governing that particular Web site. Any comments or inquiries regarding a linked Web site must be directed to its Owner. Copyright: Canadian and international intellectual property laws protect the EIP and the Content. Unless otherwise indicated, copyright is held by the Queen’s Printer for Ontario. It is recommended that reference to the Content be made in the following form: Ontario Geological Survey 2011. Airborne magnetic and electromagnetic surveys, shaded colour image of the

second vertical derivative of the residual magnetic field and Keating coefficients, Elliot Lake–River aux Sables area—Purchased data; Ontario Geological Survey, Map 60 170, scale 1:20 000.

Use and Reproduction of Content: The EIP and the Content may be used and reproduced only in accordance with applicable intellectual property laws. Non-commercial use of unsubstantial excerpts of the Content is permitted provided that appropriate credit is given and Crown copyright is acknowledged. Any substantial reproduction of the Content or any commercial use of all or part of the Content is prohibited without the prior written permission of MNDMF. Substantial reproduction includes the reproduction of any illustration or figure, such as, but not limited to graphs, charts and maps. Commercial use includes commercial distribution of the Content, the reproduction of multiple copies of the Content for any purpose whether or not commercial, use of the Content in commercial publications, and the creation of value-added products using the Content. Contact:

FOR FURTHER INFORMATION ON PLEASE CONTACT: BY TELEPHONE: BY E-MAIL:

The Reproduction of the EIP or Content

MNDMF Publication Services

Local: (705) 670-5691 Toll Free: 1-888-415-9845, ext. 5691

(inside Canada, United States) Pubsales.ndm@ontario.ca

The Purchase of MNDMF Publications

MNDMF Publication Sales

Local: (705) 670-5691 Toll Free: 1-888-415-9845, ext. 5691

(inside Canada, United States) Pubsales.ndm@ontario.ca

Crown Copyright Queen’s Printer Local: (416) 326-2678 Toll Free: 1-800-668-9938

(inside Canada, United States) Copyright@gov.on.ca

37 37

38 38

39 39

40 40

5141000 m 5141000 m

381000 m

381000 m

82

82

83

83

84

84

85

85

86

86

87

87

88

88

89

89

90

90

91

91

92

92

93

93

94

94

95

95

96

96

97

97

398000 m

398000 m

5136000 m 5136000 m

Rioux Lake

Pecors LakeStinson Lake

Pardee Lake

VanhornLake

TeesLake

FlyingGooseLake

GA

IASH

K TP.

DiabasePoint

JOU

BIN

TP.

RumPoint

Hough Lake

ShelterPoint

ElephantLake

Whitefish Lake

Deresti Lake

Whiskey Lake

GLENN N. CROMBIECONSERVATION

RESERVE

GLENN N. CROMBIE CONSERVATION RESERVE

Serpent

Riv

er

23'

24'

33' 32' 31'

30' 29'

28' 27'

26'

25' 24' 23' 22' 21' 20'30' 29' 26'

24'

33' 32' 31' 28'

23'

27' 25' 24' 23' 22' 21' 20'

46°24'51"

82°33'22"46°25'02"

82°19'20"

46°22'01"

82°19'16"82°33'17"

46°21'51"

22'

-0.0284

-0.0158

-0.0108

-0.0078

-0.0060

-0.0046

-0.0036

-0.0028

-0.0022

-0.0018

-0.0014

-0.0010

-0.0008

-0.0004

-0.0002

0.0000

0.0002

0.0004

0.0008

0.0012

0.0016

0.0022

0.0032

0.0048

0.0072

0.0122

0.0276

SHADED IMAGE SUN ANGLE

IlluminationInclination = 45°

IlluminationDeclination = 45°

Shaded image is produced by applying an artificial sun illuminationto the second vertical derivative of the magnetic field grid.

N

EW

S

Plan view

45°

Side view

Base map information derived from the Ontario Land InformationWarehouse, Land Information Ontario, Ontario Ministry of NaturalResources, scale 1:50 000.

Magnetic declination for the centre of the map area wasapproximately 9°49'W in 2011.

Keating, P.B. 1995. A simple technique to identify magneticanomalies due to kimberlite pipes; Exploration and MiningGeology, v.4, no.2, p.121-125.

Kumar, H. 2008. Report on a helicopter-borne VTEM geophysicalsurvey, Elliot Lake project; unpublished report for First UraniumInc.

Kumar, H. 2008. Report on a helicopter-borne VTEM geophysicalsurvey, Gaiashk property; unpublished report for VerbinaResources Inc.

Kumar, H. 2008. Report on a helicopter-borne VTEM geophysicalsurvey, Serpent River property; unpublished report forInternational Montoro Resources Inc.

© Queen's Printer for Ontario, 2011.

This map is published with the permission of the Director,Ontario Geological Survey.

NTS References: 41 J/7,8.

500 m 0 0.5 1 km

Scale 1:20 000

SOURCES OF INFORMATION

Data acquisition, data compilation by Geotech Ltd., Aurora,Ontario.

Data reprocessing and map production by Scott Hogg &Associates, Toronto, Ontario.

Contract management, base maps and map surrounds by theOntario Ministry of Northern Development, Mines and Forestry,Sudbury, Ontario.

To enable the rapid dissemination of information, this map hasnot received a technical edit. Every possible effort has beenmade to ensure the accuracy of the information presented;however, the Ontario Ministry of Northern Development, Minesand Forestry does not assume liability for any errors that mayoccur. Users can verify critical information from the correspondingdigital profile, gridded and EM anomaly data distributed by theOntario Geological Survey.

The geophysical data on this map were purchased from theprivate sector. The original data acquisition was neithersupervised by the Ontario Geological Survey (OGS) nor carriedout to OGS technical specifications. However, the purchaseddata do meet a pre-defined valuation criteria set out by the OGS.Some quality assurance and quality control checks have beencarried out on the digital data.

Issued 2011.

Information from this publication may be quoted if credit is given.It is recommended that reference be made in the following form:

Ontario Geological Survey 2011. Airborne magnetic andelectromagnetic surveys, shaded colour image of the secondvertical derivative of the residual magnetic field and Keatingcoefficients, Elliot Lake–River aux Sables area―Purchaseddata; Ontario Geological Survey, Map 60 170, scale 1:20 000.

CREDITS

AIRBORNE MAGNETIC ANDELECTROMAGNETIC SURVEYS

Shaded colour image of the second verticalderivative of the residual magnetic field

and Keating coefficients

MAP 60 170

Ontario Geological Survey

Purchased Data

Introduction

This survey was flown using the Geotech VTEM helicopter-borne magnetic and electromagnetic system. The aircraft wasalso equipped with a GPS navigation system and a digitaldata acquisition system.

Second Vertical Derivative of the Magnetic Field

The second vertical derivative values of the magnetic field werecomputed directly from the gridded residual magnetic intensitydata using a fast Fourier transform, combining the transferfunctions of the second vertical derivative and a half-cosine low-pass filter (100 m cut-off wavelength). The low-pass filter wasapplied in order to attenuate unwanted high frequenciesenhanced by the derivative operator.

The shaded relief parameters are:Illumination inclination: 45°Illumination declination: 45°

Magnetic declination on January 10, 2008, for the centre of thesurvey area was 8.9°W. Magnetic inclination on January 10,2008, for the centre of the survey area was 72.9°N. Magneticfield strength was 58 563 nT (calculated using the InternationalGeomagnetic Reference Field).

DESCRIPTIVE NOTES

Users of OGS products are encouraged to contact thoseAboriginal communities whose traditional territories may belocated in the mineral exploration area to discuss their project.

Positive correlation

LEGEND

75%

80%

85%

90%

Negative correlation

KEATING COEFFICIENTS

SECOND VERTICAL DERIVATIVEOF THE MAGNETIC FIELD GRID

nanoteslas per metre²(nT/m²)

Location Map 1 cm equals 10 km

AIRCRAFTType: Aerospatiale AS350B-2Registration: C-FXFU

MAGNETOMETERType: caesium-vapourSensitivity: 0.02 nTSample interval: 10 readings per secondSensor location: 15 m below aircraft

ELECTROMAGNETIC SYSTEMType: VTEMBase frequency: 30 HzCurrent waveform: trapezoidPeak dipole moment: 413 900 Am²Pulse width: 7250 µsecOff-time: 16 628 µsecParameters: Z-component of dB/dtSample interval: 10 readings per secondBird location: 35 m below aircraftFalse northing: 0 m

SURVEY PARAMETERS

Keating Correlation Coefficients

Possible kimberlite targets have been identified from the residualmagnetic intensity data, based on the identification of roughlycircular anomalies. This procedure was automated by using aknown pattern-recognition technique (Keating 1995), whichconsists of computing, over a moving window, a first-orderregression between a vertical cylinder model anomaly and thegridded magnetic data. Only the results where the absolutevalue of the correlation coefficient is above a threshold of 75%were retained. The results are depicted as circular symbols,scaled to reflect the correlation value. The most favourabletargets are those that exhibit a cluster of high-amplitudesolutions. Correlation coefficients with a negative valuecorrespond to reversely magnetized sources. It is important tobe aware that other magnetic sources may correlate well withthe vertical cylinder model, whereas some kimberlite pipes ofirregular geometry may not.

The cylinder model parameters are as follows:Cylinder diameter: 200 mCylinder length: infiniteOverburden thickness: 5 mMagnetic declination: 9°WWindow size: 10 x 10 cells (400 m x 400 m)

NAVIGATION SYSTEMGPS receiver: Novatel OEM4-G2-3151WGPS sample interval: 5 readings per secondRadar altimeter: Terra 3000/TRI-40Radar sample interval: 5 readings per secondGuidance system: GeotechDigital acquisition system: Geotech

BASE STATIONMagnetometer: Geometrics caesium-vapourMagnetometer sample interval: 1 reading per secondGPS sample interval: 1 reading per second

SURVEY SPECIFICATIONSSurvey date: January 3, 2008 to January 16, 2008Nominal aircraft terrain clearance: 85 mTraverse line spacing: 100 mControl line spacing: 1000 mTraverse line direction: North-SouthControl line direction: East-West

COORDINATE SYSTEMProjection: Universal Transverse MercatorDatum: NAD83Central meridian: 81°00'W (UTM zone 17N)Central scale factor: 0.9996False easting: 500 000 mFalse northing: 0 m