ASSESS^^^^ Report

A i rbo rne INPUT E l e c t r o m a g n e t i c & Imlagne tometer Survey

Green T m p e r i a1 Claim

(1136 ( 4 1 )

4 9 ' 0 3 ' 124'21'T.J

Nanaimo Y i n i n q D i v i s i o n

92F/lW - -

For

Imperial Metals corporat ion

BY

Stephen P, Q u i n , B.Sc., ARSM

Mining Geolo9ist

I m p e r i a l Metals ~ o r p o r a t i o n

Robert DeCasle B .A . S c ,

C h i e f Geophysicis t

Q u c s t o r Surveys L i m i t e d

March 1983

G E O L O G I C A L B R A N C H A S S E S S M E N T R E F 0 R . T

Table of C o n t e n t s

1. I n t r o d u c t i o n

2. The Proper ty

3. I t e m i z e d Cost S t a t e m e n t

4. S t a t e m e n t s of Q u a l i f i c a t i a n s

5 . Geophysical Report

List of I l l u s t r a t i o n s

Figure 1 Location Map

F i g u r e 2 C l a i m Map 1:50,000

F i g u r e 3 C l a i m ?lap 1:10,000

Figure 4 Survey Results '-

Page

2

3

In P o c k e t

In Pocket

I. T n t r o d u c t i o n --

Imperial Metals Corporation owns a 20 u n i t claim block on the

s o u t h s i d e of t h e Nanaimo River. On July 9, 1982 imperial con-

t r a c t e d Q u c s t o r S u r v e y s to fly I N P U T E?l and ?lagnetornetex su rvey

over the claim block, totalling 40 .8 l i n e kilometres.

2. The Proper ty - - -

The claim block consists of one modified g r i d claim c a l l e d t h e

Green Imper ia l , Record Number 3136(4).

See F i g u r e 2.

3, I t e m i z e d Cost Sta tc rnen t ---- C

4 0 . 8 l i n e km 05 airborn I N P U T EX & Magnetometer:

Survey $ 4 , 8 6 3 . 9 8 ~ o b i l i z a t i o n Fee 993.78

S c a l e 1:50,000 1 5 0 0 m 1

March 1983 Figure 2 S.P.Quin B.St

-3-

4. S t a t e m e n t of Oualifications

I, Stephen Paul Q u i n , of 1504 - 1260 Nelson Street, Vancouver,

B.C. state that

a) I am a permanent employee of I m p e r i a l Metals corpora t ion

w i t h o f f i c e s at s u i t e 3104 - 1055 Dunsmuir Street,

Vancouver , B .C .

b) I graduated f r o m t h e Royal School of Mines, London, Great

B r i t a i n , w i t h a Bache lor ' s Honours degree in ~ i n i n g

Geology in 1980.

c) I have been employed by Imperial Metals Corcorat ion

predecessor, Invex Resources L t d . , f o r a period of

two-and-a-half years, since gradua t ion .

28 February 1983.

a

stepfin- P. Quin B .Sc . , ARSM

Min ing Geo log i s t

b

NAME : ROBERT J, deCARLE

OCCUPATION

EDUCATION

PROFESSIONAL AFFILIATIONS

EXPERIENCE

COUNTRIES WORKED IN

LANGUAGES SPOKEN

PASSPORT #

: Chief Geophysicist

: Graduated from Lakehead University in 1967 receiving a Mining Technology D i p l o m a .

Michigan Technological University - B,A,Sc. in Geophysics, 1970.

: S o c i e t y of ~xploration Geophysicists Canadian Institute of Mining 6 Metal lurgy Canadian Exploration Geophysical Society (KEGS)

: 1965 Summer s p e n t with Noranda Mines L t d . , as underground scram helper.

: 1966 Summer spent w i t h Anaconda American Brass carrying o u t electromagnetic and magnetic s u r v e y s in Ontario.

: 1967-69 Summers spent with Hudson Bay Exploration and Development Co., as a geophysical technician and prospector,

: 1970- Present Joined Questor Surveys Limited as a

Geophysicist. Responsible for reduction of airborne d a t a both in t h e field and in-house . A l s o carried out interpretation and report writing.

Became Chief Geophysicist in 1975, responsible for a l l data reduction personnel, geophysicistts and geologists associated with airborne s u r v e y s .

: Canada, U n i t e d States, ,South Africa.

: English, French,

: FB 334746 Expires June 16, 1986.

5. Geophysical Report

The complete r epor t by R . D e C a r l e , 0 5 Questor Surveys , on the

E a s t & West Imperial claims is inc luded here,

HELICOPTER INPUT E.M. SURVEY

IMPERIAL METALS CORPORATION

GREEN MOUNTAIN AREA, VANCOWER ISLAND

B R I T I S H COLUMBIA

+ FILE NO: 24H35H SEPTEMBER, 1982.

C O N T E N T S

. . . . . . . . . . . . . . . . . . . . . . INTRODUCTION. 1

. . . . . . . . . . . . . . . . . . . . . SURVEY PROCEDURE 1

MAP COMPILATION

DATA PRESENTATION

. . . . . . . . . . . . . . . . . . . . . . . . . RESULTS 4

AREA OUTLINE

APPENDIX

EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . MARK VI I N P U T ( R ) SYSTEM . . . . . . . . . . . . . . . SONOTEK P . M . H . 5010 . . . . . . . . . . . . . . . . PROTONMAGNETOMETER

DATA SYMBOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . POSITIVE ANOMALY SYMBOL

. . . . . . . . . . . . . . . . CONDUCTIVITY-THICKNESS

SELECTED CHANNEL HALF WIDTH LIMIT . . . . . . . . . . NEGATIVE ANOMALY SYMBOL . . . . . . . . . . . . * . . ASSOCIATED MAGNETIC PEAK - . . - . . - - . * . GENERAL INTERPRETATION . . . . . . . . . . . . . . . . SAMPLE RECORD

FELICOPTER CONDUCTIVITY-THICXNESS/DEPTH NOMOGRAM

DATA SHEET

(iii)

(ii i)

(iv)

(iv)

(iv)

Iv)

Iv)

Iv)

r - INTRODUCTION I

This report c o n t a i n s t h e results of a helicopter MK VI INPUT w

survey flown in the Green Mountain area, B r i t i s h Columbia, on

1 J u l y 9 , 1982.

A brief d e s c r i p t i o n of the survey procedure is included.

The survey mileage was 40.8 line kilometres and t h e survey

was performed by QUESTOR SURVEYS LIMITED. The survey aircraft

w a s a Bell 205 ~elicopter C-GLMC and the operating base was

Nanaimo, B r i t i s h Columbia.

The area o u t l i n e is shown on a 1:50,Q00 m a p at the end of this

repart. T h i s is par t of the Nat iona l Topographical series,

sheet number 92F/l.

The following w e r e t h e pe r sonne l involved with t h e airborne survey:

P i l o t - Dan Davis

Navigator - B i l l S m i t h

Operator - Dennis Borsoi

Engineer - Laughin Currie

Geophysicist - Robert de Carle

SURVEY PROCEDURE i

T e r r a i n clearance was maintained as close to 122 metres as _- possible, with the E.M. B i r d at approximately 45 metres above

the ground. Rough terrain could be-a f ac to r for t h e helicopter

not b e i n g at 122 metres. A normal S -pa t t e rn flight path using

approximately one half kilometre turns was used . Consecutive

lines were flown in alternate d i r e c t i o n s f o r the sole purpose

of i n t e r p x e t i n g dipping conductors . This phenomenon will be

dealt with latex.

A line s p a c i n g e E 150 metres was used over t h e e n t i r e survey

area w i t h an approximate east-west fliqht d i r e c t i o n .

The equipment operator logged the flight details and monitored

t h e instruments. It was the responsibility of the geophysicist

to m a i n t a i n and check the ground magnetic s t a t i o n , Geometries

G-806, which was r eco rd ing the daily d i u r n a l changes. The

results of these recordings have been included in the f i n a l

shipment.

MAP COMPILATION

The base map f o r navigation and flight path recovery was

supplied to the contractor by t h e c l i e n t . These mylars w e r e

at a scale of approximately 1:10,000. The f i n a l map was

reproduced at a scale of 1:10,000 on stable transparent film

from which white p r i n t s can be made. A copy of the map layout

is located on each sheet u s i n g topographical reference numbers.

The map sheet is a 4 . 5 m i n u t e photographic quadrangle .

i

Flight path recovery was accomplished by comparison of the 35mm _- .

h a l f frame film with the mosaic in order to locate the fiducial

p o i n t s . Most picked p o i n t s are between 400 and 600 metres

depending on t he difficulty of the area, some picked poin t s are

much in excess of this f igure .

DATA PRESENTATION

The results of t h e INPUT survey are presented to the c l i e n t

in the following manner :

- a blank 4 . 5 minute photographic base at a scale of 1:10,000;

- a photographic base showing combined INPUT anomalies, half peak width of channel 2 , conduct ive overburden,

selected targets , skew classification and flight lines

at a scale of 1:10,OOO;

- a clear overlay showing t he contoured form o f t h e t o t a l

magnet ic field at a scale at 1:10,000.

See Appendix f o r a comprehensive description of t h e i n t e r -

pretational approach used in helicopter INPUT surveys,

QUESTOR'S conventional form for p r e s e n t i n g the hel icopter INPUT

data on a base m a p is as follows and is self-explanatory:

DECAY INTERVAL CLASSIFICATION:

,I, -.- , 1 Channel ( 340 microseconds)

2 Channel ( 540 microseconds) Sclu-~ll a Clnjr,nel S k e w Cl.~bs1lnc)l410n k .%, , t I m.0 Ilall wtdlh 1 mu1 \ t.t.,r~ovhc

P w k ;

3 Channel ( 8 4 0 microseconds)

4 Channel (1,240 microseconds) Ctn-.q,~r~cat~an s I P0517IVE NFCETNE FdCSPONSE HL SPOMSE_ _ -9 5 Channel (1,740 microseconds)

+ 6 Channel ( 2 ,340 microseconds) -

RESULTS

The survey block is located approximately 30 kilometres southwest

ef Nanaimo, B r i t i s h Columbia in t h e immediate vicinity of Green

Mountain.

V e r y few anomalies w e r e i n t e r c e p t e d d u r i n g the course of the

I N P U T survey. Those that have been p l o t t e d on the map display

very weak electromagnetic responses and most are c e r t a i n l y

within the noise envelope of 15 P . P . M . ZONE 1 is perhaps the

better of the t w o , i n that intercepts 80020A and I3 d i s p l a y some-

what of a bedrock type response and a s such, probably w a r r a n t s

further work in the f i e l d . However, it should be no ted t h a t a

s k i hill is located very close to these anomalies and as such,

cultural effects may be the cause. ZONE 2 is an extremely

weak conductor and f u r t h e r work in this area is not recommended.

The f a u l t zone is interpreted from the magnetics.

A ground reconnaissance survey is suggested in the vicinity of

ZONE 1.

R.J. de Carle, Chief Geophysicist.

APPENDIX

EQUIPMENT

T h e helicopter is equipped with a Mark VI I N P U T (R1 E.M.

system and Sonotek P .PI. A. 5010 Proton P.9agnetometer. Radar

altimeters arc used for vertical con t ro l . The o u t p u t s of

these instruments t o g e t h e r with f i d u c i a l timing marks are

recorded by means of galvanometer t ype recorders using liqht

sensitive paper. Thirty-five millimeter half frame cameras

are used to record the actual flight path.

BARRINGERJQUESTOR MARK VI INPUT (R' SYSTEM

The Induced Pulse Transient (INPUT) system is par t ic -

u l a r l y well suited to the problems of overburden penetration.

C u r r e n t s are induced into the ground by means of a pulsed

primary electromagnetic f i e l d which is generated in a

transmitting loop around t h e helicopter, By u s i n g half sine

wave c u r r e n t pulses and a loop of l a rge tu rns -a rea , the

high output power needed fo r deep penetration is achieved.

The induced c u r r e n t in a c o n d u c t o r ~roduces a secondary

electromagnetic f i e l d which is detected and measured after

the termination of each primary pulse. Detection is

accomplished by means of a receiving coil towed behind the

i helicopter on two hundred and fifty feet of cable, and the

received signal is processed and recorded by equipment in --

the helicopter. Since the measurements are in t he time

domain rather than the frequency domain common to continuous

wave systems, in terference effects of the primarv transmitted

f i e l d are eliminated. The secondary f i e l d is in the f o r m

of a decaying voltage t r a n s i e n t o r i g i n a t i n g in time at

the te rminat ion of the t r a n s m i t t e d pulse. The amplitude

of the t r a n s i e n t is, of course , proportional to the amount

of current induced i n t o t he conductor and, in turn, this

c u r r e n t is propor t ional to t h e dimensions, the conductivity

and the depth beneath the helicopter.

The rate of decay of t h e transient is inversely

proportional to conductivity. By sampling t h e decay curve

at s i x d i f f e r e n t time i n t e r v a l s , and r eco rd ing t h e amplitude

of each sample, an es t imate of the re lat ive c o n d u c t i v i t y

can be ob ta ined . By t h i s means, it is possible to discriminate

between the effects due to conductive near-surface materials

such as swamps and Lake bottom s i l t s , and those due to

g e n u i n e bedrock sources. The transients due to strong

conductors such as sulphides e x h i b i t long decay curves and

are therefore commonly recorded on all six channels. Sheet-

like surface m a t e r i a l s , on the other hand, have s h o r t decay

curves and will normally only show a response in the f i r s t

t w o or three channels.

The samples or gates are positioned at 3 4 0 , 540, 840 ,

1240, 1740 and 2340 micro-seconds after the cessation of the - pulse, The widths of t h e gates a re 200, 200, 400, 400 ,

600 and 600 micro-seconds respectively.

4 For homogeneous conditions, the transient decay will

-- - - be exponential and t h e time c o n s t a n t of decay is equa l to

the time difference at t w o successive sampling points d i v i d e d . --

by t h e log ratio of the amplitudes at these points.

SONOTEK P . M . H . 5010 PROTON ElAGNETOMETER

The magnetometers which measure the t o t a l magnetic field

have a sensitivity of 1 gamma and a range from 20,000 gammas

to 100,000 gammas.

Because of the high intensity f i e l d produced by the INPUT

t r a n s m i t t e r , the magnetometer results are recorded on a time-

s h a r i n g basis. The magnetometer head is energized while t h e

t r a n s m i t t e r is on, b u t t h e read-out is obtained d u r i n g a

short period when t h e transmitter is o f f , The precession

frequency is being recorded and converted to gammas during

the 0.2 second interval when there is no power in the trans-

mitter loop.

For this su rvey , a lag factor has been applied to the

data. Magnet ic data recorded on the analogue records at

f i d u c i a l 10.00 for example would be plbt ted at fiducial 9 .95

on the mosaics.

DATA SYMBOLOGY

The symbols used to designate the anomalies are shown - in the legend on each map sheet and t h e anomalies on each

l i n e are lettered in alphabetical order in the direction of 4

flight. T h e i r locations are p lo t t ed w i t h reference to t h e -4 ._ -

fiducial- numbers on the analog record.

A sample record is included to indicate the method used . .----

f o r correcting the position of the E.M. Bird and to identify

the parameters that are recorded.

A l l the anomaly locations, magnetic correlations,

conductivity-thickness values and the amplitudes of channel

number 2 are listed on t h e data shccts accompanying t h e

f i n a l maps.

POSITIVE ANOMALY SYMBOL + A symbol ascribed to spatially represent the position

of peak response amplitude from a conventional secondary

field direction. The convention is based on the response type

most f r e q u e n t l y detected w i t h the geometrical configuration

of the system.

CONDUCTIVITY-THICKNESS & A numerical value based on a r a t i o between early and

l a t e channe l amplitudes. It normalizes the DECAY INTERVAL

CLASSIFICATION against t he AMPLITUDE CLASSIFICATION to

derive a value based on t h e temporal rate of decay of t he

secondary field.

SELECTED CHANNEL HALF WIDTH LIMIT

A planimetric representation of the profile-derived I

h a l f - w i d t h of a positive response. It may also be used to -- -

i n d i c a t e the group half-width of multiple responses.

NEGATIVE ANOMALY SYMBOL +- A symbol ascr ibed to s p a t i a l l y reprcsent the position of peak

response amplitude from a reverse secondary f i e l d direction-

(see POSITIVE ANOMALY SYMBOL) . r

22 ASSOCIATED MAGNETIC PEAK

A symbol ascr ibed to spatially represent the position and

magnitude of a magne t i c susceptibility anomaly proximate to a ' '

recognized conductivity anomaly. For purposes of p l o t t i n g

simplifications, o n l y positive monopoles and the positive

component of dipolar responses are mapped in t h i s manner.

GENERAL INTERPRETATION

The I N P U T system will respond to conduct ive overburden

and near-surface horizontal conducting layers in a d d i t i o n to

bedrock conductors- Differentiation is based on the ra te of

transient decay, magnetic correlation and the anomaly shape

together w i t h t h e conduc to r p a t t e r n and topography.

Power l i n e s some'tirnes produce spurious anomalies b u t

these can be i d e n t i f i e d by reference to the monitor channel .

Railroad and pipeline responses are recognized by

studying the film s t r i p s .

. Graphite or carbonaceous material exhibits a w i d e i

range of conductivity. When long conductors w i thout magnetic --

correlation are located on or parallel to known f a u l t s or

photographic l inears , graphite is most l i k e l y the cause.

C o n t a c t zones can o f t e n be predicted when anomaly

t r e n d s c o i n c i d e w i t h t h e lines of maximum gradient along a

f l a n k i n g magnetic anomaly. u n f o r t u n a t e t h a t g r a p h i t e

can also occur as relatively shor t conductors and produce

a t t r a c t i v e looking anomalies. With no other i n fo rma t ion than

the airborne results , these must be examined on the ground.

Serpentinized peridotites o f t e n produce anomalies with

a character t h a t is fairly easy to recognize. The c o n d u c t i v i t y

which is probably caused in part by maqnekite, is f a i r l y low

so t h a t the anomalies o f t e n have fairly large response on

channe l # 1, they decay rapidly and they have strong magnetic

cor re la t ion . INPUT E.M. anomalies over massive magnetites

show a relationship to the t o t a l Fe c o n t e n t , Below 25-30%'

very little or no response at a l l is obtained but as the

percentage increases the anomalies become quite s t r o n g with a

charac te r i s t i c rate of decay which is usually greater than

that produced by massive sulphides.

2 Commercial sulphide ore bodies are rare and those

t h a t respond to helicopter survey methods usua l ly have medium

to h igh c o n d u c t i v i t y . Limited l a t e r a l dimensions a r e to be

expected and many have magnetic corre la t ion caused by magnetite

ox p y r r h o t i t e . Provided that the ore bodies do not occur - within format ional conductive zones as mentioned above, the

anomalies caused by them will usually be recognized on an 4

E.M. map as p r i o r i t y targets.

Power Ltne Monitor

Altimeter

Magnetometer

Fine Scale

20 Gammas

Magnetometer

Coarse S c e k

I000 Gammas - -=

1 1 Mag Locatlon Anomaly Lmatbn Fiduchf 1 knhg Mark t

I b ! - -- Representative INPUT Magnetometer and Altimeter Recording

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HORIZONTAL COIL BLOCK A

01 - ANOMALY HAW WIDTH AMPLITUDE ASSOCIATED MAG MAGNETIC

FTDWCJAL CHANNELS LEFT .RIGHT IIW CLASS SKEW SIG-T POSITION ---- -- VALUE