REPORT NO, 153

42Ei2sweeai 2.40174 MCCOMBER 010

RECEIVEDAU6 1 2 1981

MINING LANDS SECTION

DIGHEM 11 SURVEY.

IN

BEARDMORE AREA, ONTARIO

FOR

PANCONTINENTAL MINING (CANADA) LIMITED

BY

DIGHEM LIMITED

ONTARIOZ, DVORAK GEOPHYSICIST

SUMMARY

A DIGHEM11 airborne electromagnetic/magnetic/

VLF-EM survey of 129 line-km was flown in June, 1981 for

Pancontinental Mining (Canada) Ltd., in the Beardmore area

of Ontario.

The geologic environment in the survey area varied

from conductive to highly resistive. EM and resistivity

anomalies occurred due to locally conductive bedrock

features and due to culture. The EM, resistivity, VLF-EM

and magnetic techniques indicated the presence of geologic

features which may represent intrusive bodies, contacts,

dikes, etc.

Targets with conductances ranging from poor to inter

mediate were located which appear to warrant ground follow-

up work.

r

49040'

49030'

88000

LOCATION MAP

49040'

49030'

Scole h250,000

FIGURE l, THE SURVEY AREA

INTRODUCTION

A DIGHEM11 survey of 129 line-km was flown with a

300 m line-spacing for Pancontinental Mining (Canada) Ltd.,

from June 17 to June 19, 1981 in the Beardmore area, Ontario

(Figure 1).

The Alouette II turbine helicopter C-GNQX flew with an

average airspeed of 123 km/h and EM bird height of 43 m.

Ancillary equipment consisted of a Sonotek PMII-5010

magnetometer with its bird at an average height of 58 m, a

Sperry radio altimeter, Geocam sequence camera, Barringer

8-channel hot pen analog recorder, and a Sonotek SDS 1200

digital data acquisition system with a DigiData DPS 1100

9-track 800-bpi magnetic tape recorder. A HERZ Totem 1A

VLF-electromagnetometer was employed during the survey,

with the sensor towed at an average height of 65 m. The

VLF-EM receiver was tuned to NLK, Seattle, Washington,

which operates at 18.6 kHz. The analog equipment recorded

four channels of EM data at approximately 3600 Hz, one

ambient EM noise channel (for the coaxial receiver), two

multiplexed VLF-EM outputs on one channel and one channel

each of magnetics and radio altitude. The digital equipment

recorded the EM data with a sensitivity of 0.2 ppm/bit, the

magnetic field to one gamma/bit, and the VLF-EM field to 0.1

percent/bit.

- 2 -

The Appendix provides details on the data channels,

their respective noise levels, and the data reduction

procedure. The quoted noise levels are generally valid

for wind speeds up to 35 km/h. Higher winds may cause

the system to be grounded because excessive bird swinging

produces difficulties in flying the helicopter. The

swinging results from the 5 m^ of area which is presented by

the bird to broadside gusts. The DIGHEM system nevertheless

can be flown under wind conditions that seriously degrade

other AEM systems.

ELECTROMAGNETICS

DIGHEM electromagnetic responses fall into two general

classes, discrete and broad. The discrete class consists of

sharp, well defined anomalies from discrete conductors such

as sulfide lenses and steeply dipping sheets of graphite and

sulfides. The broad class consists of wide anomalies from

conductors having a large horizontal surface such as flatly

dipping graphite or sulfide sheets, saline water-saturated

sedimentary formations, conductive overburden and rock, and

geothermal zones. A vertical conductive slab with a width

of 100 m would straddle these two classes.

- 3 -

The vertical sheet (half plane) is the most common

model used for the analysis of discrete conductors. All

anomalies plotted on the electromagnetic map are interpreted

according to this model. The following section entitled

Discrete conductor analysis describes this model in detail,

including the effect of using it on anomalies caused by

broad conductors such as conductive overburden.

The conductive earth (half space) model is suitable for

broad conductors. Resistivity contour maps result from the

use of this model. A later section entitled Resistivity

mapping describes the method further, including the effect

of using it on anomalies caused by discrete conductors such

as sulfide bodies.

Discrete conductor analysis

The EM anomalies appearing on the electromagnetic map

are interpreted by computer to give the conductance (i.e.,

conductivity-thickness product) in mhos of a vertical sheet

model. DIGHEM anomalies are divided into six grades of con

ductance, as shown in Table I. The conductance in mhos is

the reciprocal of resistance in ohms.

- 4 -

Table I. EM Anomaly Grades

Anomaly Grade

654321

Mho Range

greater than 9950 - 9920 - 4910 - 195 - 9

less than 5

The mho value is a geological parameter because it is

a characteristic of the conductor alone; it generally is

independent of frequency, and of flying height or depth of

burial apart from the averaging over a greater portion ofV.

the conductor as height increases.1 Small anomalies from

deeply buried strong conductors are not confused with small

anomalies from shallow weak conductors because the former

will have larger mho values.

Conductive overburden generally produces broad EM

responses which are not plotted on the EM maps. However,

patchy conductive overburden in otherwise resistive areas

can yield discrete-like anomalies with a conductance grade

(cf. Table I) of 1 f or even of 2 for conducting clays which

1 This statement is an approximation. DIGHEM, with its short coil separation, tends to yield larger and more accurate mho values than airborne systems having a larger coil separation.

- 5 -

have resistivities as low as 50 ohm-m. In areas where

ground resistivities can be as low as 1 ohm-m, anomalies

caused by weathering variations and similar causes can have

conductance grades as high as 4. The anomaly shapes from

the multiple coils often allow such surface conductors to

be recognized, and these are indicated by the letter S on

the map. The remaining anomalies in such areas could be

bedrock conductors. The higher grades indicate increasingly

higher conductances. Examples: DIGHEM's New Insco copper

discovery (Noranda, Quebec, Canada) yielded a grade 4

anomaly, as did the neighbouring copper-zinc Magusi River

ore body; Mattabi (copper-zinc, Sturgeon Lake, Ontario,

Canada) and Whistle (nickel, Sudbury, Ontario, Canada)

gave grade 5; and DIGHEM's Montcalm nickel-copper discovery

(Timmins, Ontario, Canada) yielded a grade 6 anomaly.

Graphite and sulfides can span all grades but, in any par

ticular survey area, field work may show that the different

grades indicate different types of conductors.

Strong conductors (i.e., grades 5 and 6) are character

istic of massive sulfides or graphite. Moderate conductors

(grades 3 and 4) typically reflect sulfides of a less

massive character or graphite, while weak bedrock conductors

(grades 1 and 2) can signify poorly connected graphite or

heavily disseminated sulfides. Grade 1 conductors may not

~ 6 -

respond to ground EM equipment using frequencies less than

2000 Hz.

The presence of sphalerite or gangue can result in

ore deposits having weak to moderate conductances. As

an example, the three million ton lead-zinc deposit of

Restigouche Mining Corporation near Bathurst, New Brunswick,

Canada, yielded a well defined grade 1 conductor. The

10 percent by volume of sphalerite occurs as a coating

around the fine grained massive pyrite, thereby inhibiting

electrical conduction.

Faults, fractures and shear zones may produce anomalies

which typically have low conductances (e.g., grade 1 and 2).

Conductive rock formations can yield anomalies of any con

ductance grade. The conductive materials in such rock

formations can be salt water, weathered products such as

clays, original depositional clays, and carbonaceous

material.

On the electromagnetic map, the actual mho value and a

letter are plotted beside the EM grade symbol. The letter

is the anomaly identifier. The horizontal rows of dots,

beside each anomaly symbol, indicate the anomaly amplitude

on the flight record. The vertical column of dots gives the

- 7 -

estimated depth. In areas where anomalies are crowded, the

identifiers, dots and mho values may be obliterated. The EM

grade symbols, however, will always be discernible, and the

obliterated information can be obtained from the anomaly

listing appended to this report. .

The purpose of indicating the anomaly amplitude by dots

is to provide an estimate of the reliability of the conduc

tance calculation. Thus, a conductance value obtained from

a large ppm anomaly (3 or 4 dots) will be accurate whereas

one obtained from a small ppm anomaly (no dots) could be

inaccurate. The absence of amplitude dots indicates that

the anomaly from the coaxial coil-pair is 5 ppm or less

on both the inphase and quadrature channels. Such small

anomalies could reflect a weak conductor at the surface or

a stronger conductor at depth. The mho value and depth

estimate will illustrate which of these possibilities fits

the recorded data best.

Flight line deviations occasionally yield cases where

two anomalies^ having similar mho values but dramatically

different depth estimates, occur close together on the same

conductor. Such examples illustrate the reliability of the

conductance measurement while showing that the depth esti

mate can be unreliable. There are a number of factors which

- 8 -

can produce an error in the depth estimate, including the

averaging of topographic variations by the altimeter, over

lying conductive overburden, and the location and attitude

of the conductor relative to the flight line. Conductor

location and attitude can provide an erroneous depth esti

mate because the stronger part of the conductor may be

deeper or to one side of the flight line, or because it has

a shallow dip. A heavy tree cover can also produce errors

in depth estimates. This is because the depth estimate isV

computed as the distance of bird from conductor, minus the

altimeter reading. The altimeter can lock on the top of a

dense forest canopy. This situation yields an erroneously

large depth estimate but does not affect the conductance

estimate.

Dip symbols are used to indicate the direction of dip

of conductors. These symbols are used only when the anomaly

shapes are unambiguous, which usually requires a fairly

resistive environment.

A further interpretation is presented on the EM map by

means of the line-to-line correlation of anomalies, which is

based on a comparison of anomaly shapes on adjacent lines.

This provides conductor axes which may define the geological

structure over portions of the survey area. The. absence of

- 9 -

conductor axes in an area implies that anomalies could not

be correlated from line to line with reasonable confidence.

DIGHEM electromagnetic maps are designed to provide

a correct impression of conductor quality by means of the

conductance grade symbols. The symbols can stand alone with

geology when planning a follow-up program. The actual mho

values are plotted for those who wish quantitative data.

The anomaly ppm and depth are indicated by inconspicuous

dots which should not distract from the conductor patterns,

while being helpful to those who wish this information. The

map provides an interpretation of conductors in terms of

length, strike direction, conductance, depth, thickness

(see below), and dip. The accuracy is comparable to an

interpretation from a ground EM survey having the same

line spacing.

An EM anomaly list attached to each survey report

provides a tabulation of anomalies in ppm, and in mhos

and estimated depth for the vertical sheet model. The EM

anomaly list also shows the conductance in mhos and the

depth for a thin horizontal sheet (whole plane) model, but

only the vertical sheet parameters appear on the EM map.

The horizontal sheet model is suitable for a flatly dipping

- 10 -

thin bedrock conductor such as a sulfide sheet having a

thickness less than 15 m. The list also shows the resis

tivity and depth for a conductive earth (half space) model,

which is suitable for thicker slabs such as thick conductive

overburden. In the EM anomaly list, a depth value of zero

for the conductive earth model, in an area of thick cover,

warns that the anomaly may be caused by conductive

overburden.

Since discrete bodies normally are the targets of EM

surveys, local base {or zero) levels are used to compute

local anomaly amplitudes. This contrasts with the use of

true zero levels which are used to compute true EM

amplitudes. Local anomaly amplitudes are shown in the

EM anomaly list and these are used to compute the vertical

sheet parameters of conductance and depth. Not shown in

the EM anomaly list are the true amplitudes which are used

to compute the horizontal sheet and conductive earth

parameters.

X-type ele ct roma g ne t i c r e s po n s e s

DIGHEM11 maps contain x-type EM responses in addition

to EM anomalies. An x-type response is below the noise

threshold of 2 ppm, and reflects one of the following: a

- 11 -

weak conductor near the surface, a strong conductor at depth

(e.g., 100 to 120 m below surface) or to one side of a

flight line, or aerodynamic noise. Those responses that

have the appearance of valid bedrock anomalies on the flight

profiles are mentioned in the report. The others should not

be followed up unless their locations are of considerable

geological interest.

The thickness parameter

DIGHEM11 can provide an indication of the thickness

of a steeply dipping conductor. The ratio of the anomaly

amplitude of channel 24/channel 22 generally increases as

the apparent thickness increases, i.e., the thickness in the

horizontal plane. This thickness is equal to the conductor

width if the conductor dips at 90 degrees and strikes at

right angles to the flight line. This report refers to a

conductor as thin when the thickness is likely to be less

than 3m, and th i ck when in excess of 10 m. In base metal

exploration applications, thick conductors can be high

priority targets because most massive sulfide ore bodies

are thick, whereas non-economic bedrock conductors are

usually thin. An estimate of thickness cannot be obtained

when the strike of the conductor is subparallel to the

flight line,when the conductor has a shallow dip, when the

- 12 -

anomaly amplitudes are small, or when the resistivity of

the environment is below 100 ohm-m.

Resi st i y i ty mapping

Areas of widespread conductivity are commonly

encountered during surveys. In such areas, anomalies can

be generated by decreases of only 5 m in survey altitude as

well as by increases in conductivity. The typical flight

record in conductive areas is characterized by inphase and

quadrature channels which are continuously active; local

peaks reflect either increases in conductivity of the earth

or decreases in survey altitude. For such conductive areas,

apparent resistivity profiles and contour maps are necessary

for the interpretation of the airborne data. The advantage

of the resistivity parameter is that anomalies caused by

altitude changes are virtually eliminated, so the resis

tivity data reflect only those anomalies caused by conduc

tivity changes. This helps the interpreter to differentiate

between conductive trends in the bedrock and those patterns

typical of conductive overburden. Discrete conductors will

generally appear as narrow lows on the contour map and broad

conductors will appear as wide lows.

- 13 -

Channel 40 (see Appendix) and the resistivity contour

map present the apparent resistivity using the so-called

pseudo-layer {or buried) half space model defined in Fraser

(1978)2. This model consists of a resistive layer over

lying a conductive half space. Channel 41 gives the

apparent depth below surface of the conductive material.

The apparent depth therefore is simply the apparent thick

ness of the overlying resistive layer. The apparent depth

(or thickness) parameter will be positive when the upper

layer is more resistive than the underlying material, in

which case the apparent depth may be quite close to the

true depth.

The apparent depth will be negative when the upper

layer is more conductive than the underlying material, and

will be zero when a homogeneous half space exists. The

apparent depth parameter must be interpreted cautiously

because it will contain any errors which may exist in the

measured altitude of the EM bird (e.g., as caused by a dense

tree cover). The inputs to the resistivity algorithm are

the inphase and quadrature components of the coplanar coil-

pair. The outputs are the apparent resistivity of the

^Resistivity mapping with an airborne multicoil electromagnetic system: Geophysics, v 43, p. 144-172.

- 14 -

conductive half space (the source) and the sensor-source

distance. The flying height is not an input variable,

and the output resistivity and sensor-source distance are

independent of the flying height. The apparent depth,

discussed above, is simply the sensor-source distance minus

the measured altitude or flying height. Consequently,

errors in the measured altitude will affect the apparent

depth parameter but not the apparent resistivity parameter.

The apparent depth parameter is a useful indicator of

simple layering in areas lacking a heavy tree cover. The

DIGHEM11 system has been flown for the purpose of

permafrost mapping, where positive apparent depths were

used as a measure of permafrost thickness. However, little

quantitative use has been made of negative apparent depths

because the absolute value of the negative depth is not a

measure of the thickness of the conductive upper layer and,

therefore, is not meaningful physically. Qualitatively, a

negative apparent depth estimate usually shows that the EM

anomaly is caused by conductive overburden. Consequently,

the apparent depth channel 41 can be of significant help in

distinguishing between overburden and bedrock conductors.

- 15

Interpretation in conductive environments

Environments having background resistivities below

30 ohm-m cause all airborne EM systems to yield very

large responses from the conductive ground. This usually

prohibits the recognition of bedrock conductors. The

processing of DIGHEM11 data/ however, produces four

channels which contribute significantly to the recognition

of bedrock conductors. These are the inphase and quadrature

difference channels (number 33 and 34), and the resistivity

and depth channels (40 and 41). The EM difference channels

eliminate up to 99% of the response of conductive ground,

leaving responses from bedrock conductors, cultural features

(e.g., telephone lines, fences, etc.) and edge effects.

An edge effect arises when the conductivity of the ground

suddenly changes, and this is a source of geologic noise.

While edge effects yield anomalies on the EM difference

channels, they do not produce resistivity anomalies.

Consequently, the resistivity channel aids in eliminating

anomalies due to edge effects. On the other hand, resis

tivity anomalies will coincide with the most highly conduc

tive sections of conductive ground, and this is another

source of geologic noise. The recognition of a bedrock

conductor in a highly conductive environment therefore

is based on the anomalous responses of the two difference

- 16 -

channels {33 and 34) and the resistivity channel (40). The

most favourable situation is where anomalies coincide on all

three channels.

Channel 41, which is the apparent depth to the conduc

tive material, also helps determine whether a conductive

response arises from surficial material or from a conductive

zone in the bedrock. When this channel rides above the zero

level on the orange profile paper (i.e., it is negative), it

implies that the EM and resistivity profiles are responding

primarily to a conductive upper layer, i.e., conductive

overburden. If channel 41 is below the zero level, it

indicates that a resistive upper layer exists, and this

usually implies the existence of a bedrock conductor.

Channels 35 and 36 are the anomaly recognition

functions. They are used to trigger the conductance

channel 37 which identifies discrete conductors. In highly

conducting environments, channel 36 may not be generated

because it is subject to some corruption by highly conduc

tive earth signals. Some of the automatically selected

anomalies (channel 37) are discarded by the human interpre

ter. The automatic selection algorithm is intentionally

oversensitive to assure that no meaningful responses are

missed. The interpreter then classifies the anomalies

- 17 -

according to their source and eliminates those that are

not substantiated by the data, such as those rising from

geologic or aerodynamic noise.

The resistivity map often yields more useful informa

tion on conductivity distributions than the EM map. In

comparing the EM and resistivity maps, keep in mind the

following:

(a) The resistivity map portrays the absolute

value of the earth's resistivity.

(b) The EM map portrays anomalies in the earth's

resistivity. An anomaly by definition is

a change from the norm and so the EM map

displays anomalies, (i) over narrow, conduc

tive bodies and (ii) over the boundary zone

between two wide formations of differing

conductivity.

The resistivity map might be likened to a total field

map and the EM map to a horizontal gradient in the direction

- 18 -

of flight-*. Because gradient maps are usually more sensi

tive than total field maps, the EM map therefore is to be

preferred in resistive areas. However, in conductive areas,

the absolute character of the resistivity map usually causes

it to be more useful than the EM map.

Reduction of geologic noise

Geologic noise refers to unwanted geophysical

responses. For purposes of airborne EM surveying, geologic

noise refers to EM responses caused by conductive overburden

and magnetic polarization. It was mentioned above that the

EM difference channels (i.e., channel 33 for inphase and 34

for quadrature) tend to eliminate the response of conductive

overburden. This marked a unique development in airborne EM

technology, as DIGHEM11 is the only EM system which yields

channels having an exceptionally high degree of immunity to

conductive overburden.

Magnetite produces a form of geological noise on the

inphase channels of all EM systems. Rocks containing less

gradient analogy is only valid with regard to the identification of anomalous locations. The calcula tion of conductance is based on EM amplitudes relative to a local base level, rather than to an absolute zero level as for the resistivity calculation.

- 19 -

than 11 magnetite can yield negative inphase anomalies

caused by magnetic polarization. When magnetite is widely

distributed throughout a survey area, the inphase EM chan

nels may continuously rise and fall reflecting variations

in the magnetite percentage, flying height, and overburden

thickness. This can lead to difficulties in recognizing

deeply buried bedrock conductors, particularly if conductive

overburden also exists. However, the response of broadly

distributed magnetite generally vanishes on the inphase

difference channel 33. This feature can be a significant

aid in the recognition of conductors which occur in rocks

containing accessory magnetite.

MAGNETICS

The existence of a magnetic correlation with an EM

anomaly is indicated directly on the EM map. An EM anomaly

with magnetic correlation has a greater likelihood of being

produced by sulfides than one that is non-magnetic. How

ever, sulfide ore bodies may be non-magnetic (e.g., the

Kidd Creek deposit near Timmins, Ontario, Canada) as well

as magnetic (e.g., the Mattabi deposit near Sturgeon Lake,

Ontario).

- 20 -

The magnetometer data are digitally recorded in

the aircraft to an accuracy of one gamma. The digital

tape is processed by computer to yield a standard total

field magnetic map which is usually contoured at 25 gamma

intervals. The magnetic data also are treated mathematic

ally to enhance the magnetic response of the near-surface

geology, and an enhanced magnetic map is produced with a

100 gamma contour interval. The response of the enhancement

operator in the frequency domain is shown in Figure 2. The

100 gamma contour interval is equivalent to a 5 gamma inter

val for the passband components of the airborne data. This

is because these components are amplified 20 times by the

operator of Figure 2.

The enhanced map, which bears a resemblance to a

downward continuation map, is produced by digital bandpass

filtering the total field data. The enhancement is equiva

lent to continuing the field downward to a level {above

the source) which is 1720th of the actual sensor-source

distance.

Because the enhanced magnetic map bears a resemblance

to a ground magnetic map, it simplifies the recognition

of trends in the rock strata and the interpretation of

geological structure. The contour interval of 1-00 gammas

AM

PLIT

UD

E

o c: •n

O

o o

^-O

O c *JI o f 3

o tO

3

O O*

O r-

m

to O o

to

v-

- 22 -

is suitable for defining the near-surface local geology

while de-emphasizing deep-seated regional features.

VLF-EM

VLF-EM anomalies are not EM anomalies in the conven

tional sense. EM anomalies primarily reflect eddy currents

flowing in conductors which have been energized inductively

by the primary field. In contrast, VLF-EM anomalies prima

rily reflect current gathering, which is a non-inductive

phenomenon. The primary field sets up currents which flow

weakly in rock and overburden, and these tend to collect in

low resistivity zones. Such zones may be due to massive

sulfides, shears, river valleys and even unconformities.

The Herz Industries Ltd Totem 1A VLF-electromagne-

tometer measures the total field and vertical quadrature

component. Both these components are digitally recorded in

the aircraft with a sensitivity of 0.1 percent/bit. The

total field yields peaks over VLF-EM current concentrations

whereas the quadrature component yields crossovers. Both

appear as traces on the profile records. The total field

data also are filtered digitally and displayed on a contour

map, to facilitate the recognition of trends in the rock

strata and the interpretation of geologic structure.

-23-

UJ

-J 0.z

ACCEPT

CYCLES/FOOT

Figure 3 Frequency response of VLF-EM operotor

- 24 -

The response of the VLF-EM total field filter operator

in the frequency domain (Figure 3) is basically similar to

that used to produce the enhanced magnetic map (Figure 2).

The two filters are identical along the abscissa but

different along the ordinant. The VLF-EM filter removes

long wavelengths such as those which reflect regional and

wave transmission variations. The filter sharpens short

wavelength responses such as those which reflect local

geological variations. The filtered total field VLF-EM

contour map is produced with a contour interval of one

percent.

CONDUCTORS IN TflE SURVEY AREA

The electromagnetic map shows the location of conduc

tors and their interpreted conductance (i.e., conductivity-

thickness product), depth and, occasionally, the dip. Their

strike direction and length are also shown when anomalies

can be correlated from line to line. When studying the maps

for follow-up planning, consult the anomaly listing appended

to this report to ensure that none of the conductors are

overlooked.

- 25 -

The survey consisted of 34 lines flown in a northwest

direction with a line spacing of 300 in. The EM maps

indicate which anomalies are believed to be caused by

culture or surficial sources. Generally, such anomalies

are not commented on below as the discussions are directed

to identifying bedrock features.

Numerous cultural sources, such as power lines, rail

roads, buildings, etc., exist along the northern boundary

of the survey area. They have produced spurious EM and

resistivity anomalies which can be readily recognized on the

environmental channel 28 of the grey digital profiles and on

the environmental channel and 60 Hz fiducial marker of the

green analog charts.

The survey area is characterized by ground resis

tivities which range from about 4 ohm-m to in excess of

1,000 ohm-m. The resistivity map displays prominent narrow

low resistivity trends of a northeasterly direction. The

most conspicuous feature of the resistivity map is the high

resistivity zone between lines 12 and 16, inclusive, which

cuts across the low resistivity trends in a north-north

westerly direction.

- 26 -

Magnetic data in the southeastern part of the survey

block shows a northeasterly trending belt of high magnetic

activity which extends from the eastern boundary towards the

center of the survey area. The enhanced magnetic map

indicates that this belt consists of a series of narrow

parallel features. In the west it abruptly terminates in

a narrow strongly negative feature which parallels line 16.

The close examination of the total magnetic field map and

line 16 profile reveals that the magnetic lows correlate

with negative inphase responses of the EM system {channels

22 and 24). This means that the lows occur due to magneti

cally polarizable material, most likely magnetite, which

has acquired a strongly negative (i.e., reversed) remanent

component at the time of its formation. It is proposed that

the feature may reflect a very narrow dike paralleling line

16, possibly slightly undulating in the lateral sense.

(Note that the EM data also portrays the magnetite content -

see channel 50.) It is further proposed that the magnetic

low zone between lines 16 and 9 may reflect an intrusive

body. It is of interest to note that this zone is charac

terized by ground resistivities in excess of 4,000 ohm-m.

The VLF-EM technique has revealed prominent trends of

a northeasterly direction. In the north part of the survey

- 27 -

area, these trends appear to reflect culture, e.g., along

the Trans-Canada Highway and along the gas pipeline.

Further south, they reflect geologic targets.

A very good correlation exists between different

geophysical parameters. Note, for example, the close

correlation between EM, resistivity, magnetic and VLF data

in the eastern part of the survey area. The EM anomalies

which have produced low resistivity zones correlate with the

high magnetic activity, as well as with the narrow, confined

VLF-EM trends.

Anomalies 1E-11H, 1G-10G, 2E-8xC, 3F-10D

These grade 1 to 4 anomalies

reflect bedrock conductors which

occur in the form of narrow

multiple bands (see, for example,

the analog charts of line 8 in

the vicinity of fiducial 533).

The conductors terminate in the

vicinity of Pauline Lake, at the

edge of the proposed intrusive

body.

Anomalies 9D, 17F-32F, These grade 1 to 4 anomalies 28D-34H, 30C, 32D-34G reflect a series of bedrock

- 28 -

conductors which occur on the

flanks of a narrow magnetic trend

best portrayed by the enhanced

magnetic map. Note that the EM

responses on lines 10 to 16 are

obscured by cultural responses

from the railroad. It would seem,

however, that 9D and 16F may be

part of the same conductor as

17F-32F.

Group 1 A series of east-northeasterly

striking parallel conductors is

indicated by these grade 1 to 5

anomalies. Practically every

individual conductor indicated

on the EM map consists of a set

of thin vertically dipping sheet-

like bodies (see, for example,

the analog charts of lines 23 or

28). Note that the conductors

occur close to the crest of the

magnetic anomalies. Direct

magnetic correlation, however,

- 29 -

exists only sporadically, e.g., at

27F, 28H, 281, 29F, 30F, 30H, 32xB,

34J.

Anomalies 24D, 33G,33H

Responses 22xB, 27xA,30xB

These single-line grade 1 anomalies

and x-type responses appear to

reflect short bedrock conductors

which parallel the group 1 conduc

tors.

Respectfully submitted, DIGHEM LIMITED

Z. Dvorak Geophysicist

Five map sheets accompany this report,

ElectromagneticsResistivityMagneticsEnhanced magneticsFiltered total VLF-EM field

1 map sheet 1 map sheet 1 map sheet 1 map sheet 1 map sheet

F ZD-29

A P P K N D I X A

THE FLIGHT RECORD AND PATH RECOVERY

Both analog and digital flight records are produced. The

analog profiles are recorded on green chart paper in the aircraft

during the survey. The digital profiles are generated later by

computer and plotted on orange chart paper at' a scale identical

to the geophysical maps. The digital profiles, which may be

displayed, are as follows:

Channel dumber/ Label Parameter

20212223242526272829333435363740414546

HAGALTCXICXQ .CPICPQVLFTVJ.FQCXSCPSDI FIDIFORKC1KEC2SIGTRESDPKES2DP 2

magnetometerbird heightcoaxial coil-pair inphasecoaxial coil-pair quadraturecoolanar coil-pair inphasecoplanar coil-pair quadratureVLF-EM total fieldVLF-EX vertical quadratureambient noise monitor (coaxial coil)ambient noise monitor (cop3vanar coil)difference function inphasedifference function quadraturefirst anomaly recognition functionsecond anomaly recognition functionconductancelog resistivity at main frequencyapparent depth at main frequencylog resistivity at secondary frequencyapparent depth at secondary frequency

Scale units/mm

101011111-11111111

.033

.033

gammafeetpprnppmppmpwnS4ppmppmppmppmppmppmjnhodecademdecadem

Noise

2 gamma5 feet1-21-21-21-21-21-2

11

1-21-21-21-2

ppmpp.-nppmppmiippmppmppmppmppmppm

Note: Channels 42 to 44 are experimental.

(li)

The log resistivity scale of 0.03 decade/mm means that

the resistivity changes by an order of magnitude in 33 mm.

The resistivities at O, 33, 67 and 100 mm up from the bottom

of the chart are respectively l, 10, 100 and 1000 ohm-m.

The fiducial marks on the flight records represent

points on the ground which were recognized by the aircraft

navigator. Continuous photographic coverage allowed

accurate photo-path recovery locations for the fiducials,

which were then plotted on the geophysical maps to provide

the track of the aircraft.

The fiducial locations on both the flight records and-

flight path maps were examined by a computer for unusual

helicopter speed changes. Such changes may denote an error

in flight path recovery. The resulting flight path

locations therefore reflect a more stringent checking than

is provided by standard flight 'path recovery techniques.

The following brief description of DIGHEM11

illustrates the information content of the various

profiles*.

*For a detailed description, see D.C. Fraser, Geophysics, v.44, p.1367-1394.

(lil)

Single-frequency surveying

The DIGHEM11 system has two transmitter coils which

are mounted at right angles to each other. Both coils

transmit at approximately the same frequency. (This

frequency is given in the Introduction.) Thus, the system

provides two completely independent surveys at one pass. In

addition, the digital flight chart profiles (generated by

computer) include an inphase channel and a quadrature

channel which essentially are free of the response of

conductive overburden. Also, the EM channels may indicate

whether the conductor is thin (e.g., less than 3m), or has

a substantial width (e.g., greater than 10 m). Further, the

EM channels include channels of resistivity, apparent depth

and conductance. A minimum of 11 EM channels are provided.

The DIGHEM 11 system therefore gives information in one

pass which cannot be obtained by any other airborne or

ground EM technique.

Figure Al shows a DIGHEM11 flight profile over the

massive pyrrhotite ore body in Montcalm Township, Ontario.

It will serve to identify the majority of the available

channels.

(lv)

11NC S., . :~'—-

-r-Hinphoco-4-i-

rTrTphoTo—i—l

-j - ,, ,., i — l--, -.,.-. — ..-~ First-cnDfooly-recoonition-Hunclio

r1.- Second -ononioly recognition -function

Fig. Al. Flight over Montcalm deposit, with line parallel to strike

(v)

The two upper channels (numbered 20 and 21) are

respectively the magnetics and the radio altitude. Channels

22 and 23 are respectively the inphase and quadrature of the

coaxial coil-pair, which is termed the standard coil-pair.

This coil-pair is equivalent to the standard coil-pair of

all inphase-quadrature airborne EM systems. Channels 24 and

25 are the inphase and quadrature of the additional coplanar

coil-pair which is termed the whaletail coil-pair.

Channels 31 and 32 are inphase and quadrature sum

functions of the standard and whaletail channels; they

provide a condensed view of the four basic channels 22 to

25. The sum channels normally are not plotted.

Channels 33 and 34 are inphase and quadrature

difference functions of the standard and whaletail

channels. The difference channels are almost free from the

response of conductive overburden. Channel 37 is the

conductance. The conductance channel essentially is an

automatic anomaly picker calibrated in conductance units of

mhos; it is triggered by the anomaly recognition functions

shown as channels 35 and 36.

(vi)

Channel 40 is the resistivity, which is derived from

the whaletail channels 24 and 25. The resistivity channel

40 yields data which can be contoured, and so the DIGHEM11

system yields a resistivity contour map in addition to an

electromagnetic map, a magnetic contour map, and an enhanced

magnetic contour map. The enhanced magnetic contour map is

similar to the filtered magnetic map discussed by Fraser.*

Figure A2 presents the DIGHEM1 * results for a line

flown perpendicularly to the Montcalm ore body. Channel 20

shows the 175 gamma magnetic anomaly caused by the massive

pyrrhotite deposit. For the EM channels, the following

points are of interest:

1. On channels 22-25 and 31-34, the ore body essentially

yields only an inphase response. The quadrature

response is almost completely caused by conductive

overburden (which also gives a small inphase

response). The hachures show the EM response from the

overburden. The overburden response vanishes on the

*Cdn. Inst. Mng., Bull., April 1974.

(yii)

L!Nf l?

EEB2H3333EE

Fig. A2. Flight over Montcalm deposit, with line perpendicular to strike.

(viii)

difference EM channels, as can be seen by comparing the

quadrature channels 25 and 34. This is an important

point to note because DIGHEM11 is the only EM system

which provides an inphase channel and a quadrature

channel which are essentially free of conductive

overburden response.

2. The whaletail anomaly of channel 24 has a single peak.

This shows that the conductor has a substantial width.

If the width had been under 3 m, the conductor would

have produced a weak m-shaped anomaly on channel 24.

3. The ore body yields a resistivity of 5 ohm-m in a

background of about 200 ohm-m (cf. channel 40). A

dipole-dipole ground resistivity survey with an

a-spacing of 50 m showed a similar background, but the

ore body gave a low of only 53 ohm-m because of the

averaging effect inherent .in the ground technique.

4. The ore body has a conductance of 330 mhos according to

its EM response on this particular flight line. The

conductance channel 37 saturates at 100 mhos, and so

the deposit is indicated by a 100-mho spike.

(ix)

Figure Al illustrates the DIGHEM11 results for a line

flown subparallel to the ore body. The ore body anomaly is

small on the standard coil-pair (channel 22) but shows up

strongly on the whaletail coil-pair (channel 24).

Dual-frequency surveying

For surveys flown primarily for resistivity mapping, as

opposed to EM surveying, the two transmitter coils may be

energized at two well-separated frequencies (e.g., 900 and

3600 Hz). Apparent resistivity and apparent depth maps can

be made independently for each frequency. The inter

pretation procedure involves comparing the apparent

resistivities and apparent depths at the two frequencies.

The use of two different coil-pair orientations (i.e.,

standard and whaletail) for dual-frequency resistivity

mapping is an unorthodox procedure. However, as long as the

current flow patterns are primarily horizontal, the

different coil orientations do not influence the results,

according to superposed dipole theory. Wire fences and

other cultural features will produce local deviations,

(x)

because they usually respond preferentially to one or the

other of the coil-pairs.

The difference channels 33 and 34 are not produced

because the divergent frequencies of the two coil-pairs

renders them meaningless. In addition, channels 35 to 37

also are not produced.

APPENDIX B

EM ANOMALY LIST

PANCONTINENTAL, 3EAROMORE AREA

COAXIAL

LINE iANOMALY

1AIB1CIDIE1G

2A2B2C2E2F2G

3A3B3C3D3E3F3H31

4A484C4D4E

5A5B5C5D5E

CO

REALPPM

140

104

1435

582

211614

134

23227

1030

9766

26

79

124

12

IL

CUADPPM

82528

15

245887

120

4610259

5313

10

44305

CDPLCO

REALPPM

31030

1343

0170

137

10

10

490051

34

3541

28

27

1041

ANARIL

QUADPPM

10

1306

25

073497

40

930015

16

0313

16

31306

. VERTICAL DIKE

* t

. COND DEPTH*,

. MHOS FEET ,

HORIZONTAL SHEET

CONDUCTIVE EARTH

512 l 5 8

362

1145

212 l l

11 3

11

55

4038

36

10124

72562644

12214

22O

40 39 10 32

59142

O171 201 173 11236

9911117510761

136110126213109

CONDMHOS

111111

111111

11111111

11211

11221

DEPTHFEET

136178108141343203

532130134361237347

23417850

157403376351247

202353375360281

335210330337337

RESISOH M- M

668145358

143115228

414083

308236

31572

48314596

5714841

12127

32233214931

1368295151451

DEPTHFEET

57700

235142

0910

285139251

91770

27317293250185

73278304276215

13784

270277255

ESTIMATED DEPTH MAY BE UNRELIABLE BECAUSE THE STRONGER PARTOF THE CONDUCTOR HAY 3E DEEPER OR TD ONE SIDE OF THE FLIGHTLINE, OR BECAUSE OF A SHALLOW DIP OR OVERBURDEN EFFECTS.

153WH1 PANCQNTINENTAL, 3EAROMORE AREA

COAXIAL COIL

LINE t REAL QUAD ANOMALY PPM PPM

CDPLANAR COIL

RtAL QUAD PPM PPM

VERTICAL DIKE

COND MHOS

DEPTH*, FEET ,

HORIZONTAL SHEET

COND DEPTH MHOS FEET

CONDUCTIVE EARTH

RESIS C H M-M

DEPTH FEET

5G 12 13 12 47 . 255 114 161

6A6B6C6D6E

6104

1115

33058

31327

17

6307

10

tt

m

*

*

. a

2132545

54 .122 .246 .90 .29 .

12211

204327338306272

40813203674

59263272235184

7A7B7C7D7E7F

31075

1010

30 .3045

10

141679

193368

tt

tt

tt

tt

tt

tt

622104744

93 .81 .

116 .126 .120 .27 .

111311

488112366330377260

41408542410

105194

00

295277275139

8A 8B 8C 8D

8

135

5242

1116134

5662

tt

tt

tt

tt

41794

12390

10282

tt

tt

tt

tt

1211

393311339428

1101725

177

290249273295

9A9B9C9D9E9F9G

8171274

1411

513166647

34495

114

0526763

tt

tt

*

tt

*

tt

tt

43 -

22194

100750

78878142

*

tt

tt

*

*

tt

*

1111111

540342276362348364608

41401351973205417104156

014385

236187261465

10B10C10D10E10F

82

10205

64

1166

11

14142

62982

*

tt

*

*

tt

21291

44 .130 .76 .83 .

137 .

11111

168353335364388

3233414029684

474

00

194263219

.* ESTIMATED DEPTH MAY BE UNRELIABLE BECAUSE THE STRONGER PART

. CF THE CONDUCTOR MAY 3E DEEPER OR TO ONE SIDE OF THE FLIGHT

. LINE, OR BECAUSE OF A SHALLOW DIP OR OVERBURDEN EFFECTS.

H i

PANCONTINENTAL, BEARDMORE AREA

COAXIAL COPLANAR COIL COIL

LINE t REAL QUAD REAL ANOMALY PPM PPM PPM

QUAD PPM

VERTICAL DIKE

COMD MHOS

DEPTH*, FEET ,

HORIZONTAL SHEET

COND DEPTH MHOS FEET

CONDUCTIVE EARTH

RESIS OHM-K

DEPTH FEET

10G 15 10 80 572 42 475

11BHE11G11H111UK

121041022

17137233

3115

1200

48

20633

221911

0 .48 .0 .

106 .133 .127 .

111111

467216163306275291

4140944772282

41404140

05815

16300

12B12D12E12F

10170

6277

3140

3101210

4111

01

210

*

m

*

*

1111

347137212144

4140414012394140

00

340

13A 13B

153

214

2 l

32

23

O 87

l l

207660

13854140

4 O

14A14B14C140

15

110

10242

7240

6293

1331

01534779

*

*

*

*

1111

180434230373

4140414015014140

00

780

ISA 15C15D

576

432

O 3 O

Oo o

l42

O87 8

ll l

426344177

20637051032

ESTIMATED DEPTH MAY BE UNRELIABLE BECAUSE THE STRONGER PART OF THE CONDUCTOR MAY 3E DEEPER OR TO ONE SIDE OF THE FLIGHT LINE, OR BECAUSE OF A SHALLOW DIP OR OVERBURDEN EFFECTS.

276O O

is; ,H1 PANCDNTINENTAL, BEARDMORE AREA

COAXIAL

LINE LANOMALY

16C16D16E16F

17C17D17E17F17G17H17117J17K

18A18B18C18D18E18F18G18H

19B19019F19G

CDI

REALPPM

12275

896

11786

1120

316055

101513

417

14

L

CUADPPM

3730

51353125S

10

40

13020

100

4819

COPLANARCOIL

REALPPM

10532

21457B63

1624

1300

11131524

01315

QUADPPM

2300

2112001022

12

003011

140

3237

VERTICALDIKE

COND DEMHOS F

8128

223

2136122

117

1514

16494

49

1163

HORI ZONTALSHEET

PTH*.EET .

19 .68 .77 .94 .

12 .1 .

96 .125 .130 .114 .149 .109 .21 .

107 .63 .1 .

167 .183 .114 .42 .

105 .

81 .19 .89 .96 .

CONDMHOS

1111

111111111

11111412

1211

DEPTHFEET

94124120350

0213309413468463365320238

370290127197373297261320

518370267340

CONDUCTIVEEARTH

RESISOHM-K

544601

1130883

276722514286

134117400154138

397339914417585

4314

288619

637296

DEPTHFEET

080

134

091

205309345343207211135

204144

260

286253187261

9929791

199

.* ESTIMATED DEPTH MAY BE UNRELIABLE BECAUSE THE STRONGER PART

. OF THE CONDUCTOR MAY BE DEEPER OR TO ONE SIDE OF THE FLIGHT

. LINE, OR BECAUSE OF A SHALLOW DIP OR OVERBURDEN EFFECTS.

PANCQNTINENTAL, 8EARDMORE ARcA

COAXIAL COIL

COPLANAR COIL

LINE t REAL QUAD REAL QUAD ANOMALY PPM PPM PPM PPM

19H 191 19J

20A 20B 200 20E 20F

21A 21C 21E 21F

22A 22B 22C 22D 22E 22F

23A 238 23C 23E 23F 23G

112723

59

23176

1714216

75

19242015

O 4

19 13 10 24

4133

l 3 9 3 6

4544

9245

149

17 l 3 393

141824

51147228

1915242

52

28351623

2 O

18224

24

5116

O2

133

10

4554

11 O 87

168

3 O4578

VERTICALDIK

CCNDMHOS

107

14

5121530' 2

209

232

15

172447

-

19

31262

11

t.

DEPTH*FEET

362892

12074399459

1163954

161

15196108566062

0230106818766

4

4

4

4

4

4

4

4

4

4

4

4

.

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

.

4

4

4

4

.

4

4

4

4

HORIZONTALSH

CONDMHOS

111

22341

2131

112311

112312

EET

DEPTHFEET

364312344

490342225328294

362312295423

217331330272272304

275475364303359321

CONDUCTIVEEARTH

RESISOHM-M

404924

131454

180

14249

274

296351107

9022

6333369

138

16517

DEPTHFEET

283231280

427279185294177

302243243279

86181277226189241

10373

304254246260

24A 21 16

ESTIMATED DEPTH MAY Bc UNRELIABLE OF THE CONDUCTOR MAY 3E DEEPER OR LINE, OR BECAUSE OF A SHALLOW DIP

47 79 1578

BECAUSE THE STRONGER PART TO ONE SIDE OF THE FLIGHT O* OVER3UR05N EFFECTS.

;Ri PANICONTINENTAL, 3EARDMORE AREA

COAXIAL

LINE E,ANOMALY

24824C24D24E24F24G24H

25B25C25E25F25G

26A26B26C26D26F26G26H261

27B27C27D27627F27G27H

28A286

COI

REALPPM

6133

164

317

1320123728

9147

20277

7341

2414355

107

04

L

CUADPPM

0224469

58788

41249

124

164

251473242

325

CDPLANAR COIL

REAL QUAD PPM PPM

O 123

17O

449

2278

3832

O 8 2

2221O

95 50

3627793

28 O

O 2 2479

11

O 8

13 12 10

5174

10116

319

21 2 O2323

33 O

VERTIDIK

CONDMHOS

4222

191

261

10103

2115

223882

2556

3335695

11

CALCk* *

*

DEPTH*.FEET .

190 .106 .207 .53 .

122 .52 .55 .

90 .98 .44 .76 .75 .

*

88 .36 .98 .32 .93 .86 .50 .16 .

0 .41 .87 .18 .30 .43 .6 .

0 .97 .

HORI ZONTALSHEET

CONDMHOS

1212131

11122

11111134

1111331

11

DEPTHFEET

371378477281347257271

243308240282295

7790

224277308257212220

0138242343313422456

186362

CONDUCTIEARTH

RESIS DEOHM-M F

85416

14515

1896

236

79523961319

4140855

11403734

12254

303712991026

4687

84

124720

VE

PTHSET

180312356221223214145

85248154229238

00

51205240161174185

00

72254261377344

92186

ESTIMATED DEPTH MAY BE UNRELIABLE OF THc CONDUCTOR MAY 8E DEEPEN OR LINE, OR BECAUSE OF A SHALLOW DIP

BECAUSE THE STRONGER PART TO ONE SIDE OF THE FLIGHT OR OVER3URDEN EFFECTS.

PANCONTINENTAL, 3EAROMORE AREA

COAXIAL

LINE f*ANOMALY

28C28D28E28G28H281

29A29B29C29D29 E29F

30A30B30C30D30E30FBOG30H

31A31831C31D31E31F31G

32A32B32C32D

CO

REALPPM

61617308456

1336

15185

3838

3324231163

312252

34474

111732

IL

CUADPPM

4277

1422

1133322

111457

1155

33

2474

1361

31041

COPLANARCOIL

REAL QUADPPM

1147

2910061

2015789

1627

3422175

69

46

390

39486

1707

PPM

205

132634

423635

38

126874

49

01770

21111

0080

VERTICAL DIKE

COND MHOS

2496

143910

5559

285

1212

319

1558

23

2129

4114

3 5 l 5

.# ESTIMATED DEPTH MAY BE UNRELIABLE

. OF TH5 CONDUCTOR MAY BE DEEPER ORLINE, OR BECAUSE OF A SHALLOW DIP

DEPTH*, FEET ,

1206890274526

2399

1202

5324

63 O

7764

1021725O

1475463

176502470

O O

15 105

HORIZONTAL SHEET

COND DEPTH MHOS FEET

CONDUCTIVE EARTH

l l12 4 l

l l l12 l

ll l l l l l l

l12 l l 3 2

l ll l

239299324255215207

375257449331414340

367279214270330301350170

471164232338246246430

56964392

242

RESISOHM-M

12646079164

24

341562118451342

101850253343636

39433

16538651641325

17

4140261

4140142

DEPTHFEET

59213234198180151

29657

332249353255

2699393

203260223182111

17918

182264182207354

0473

0137

BECAUSE THE STRONGER PART TO ONE SIDE OF THE FLIGHT OR OVERBURDEN EFFECTS.

PANCQNTINENTAL, BEARDMORE AREA

COPLANAR COIL

REAL QUAD PPM PPM

HORIZONTAL SHEET

CONO DEPTH MHOS FEET

CONDUCTIVE EARTH

32E32F32G32H321

. 10561

16

21161

150

115

10

00

1693

37431

35

84142

608

*

*

*

*

*

21111

327400143178351

1827

24143127

2603192235

271

33B33C33D33E33F33G33H33133J33K

13137

463307

331335

002

231835

25373

000

616005

532932

300

272515

53859

14389

1081241

46

122 .180 .172 .33 .29 .

231 .118 .

0 .0 .

51 .

1111111112

31543226117918541935012970

297

39532515432523

414056961

22718

0294105125130

0180610

237

34A34C34E34F34G34H34134J34K

4092

13115

1311

52243650

143

3297

19180

356

13700360

463

11327912'

11

16 .0 .

69 .113 .

0 .11 .49 .0 .

66 .

111111111

67970158016822025425076

339

30244140515

240359677895

448

1850

3820

137165160

0163

ESTIMATED DEPTH HAY BE UNRELIABLE BECAUSE THE STRONGER PARTOF THE CCNDUCTCR MAY SE DEEPER OR TO ONE SIDE OF THE FLIGHTLINE, OR BECAUSE OF A SHALLOW DIP OR OVERBURDEN EFFECTS.

!KAL TERMINATION OF JOB

a

Ministry of Nat

Ontarior UfcurniaiUAL-ljfcUlAA ^eissweeai z 4*74 MCCOMBER j TECHNICAL DA1

TO BE ATTACHED AS AN APPENDIX TO TECHNICAL REPORT FACTS SHOWN HERE NEED NOT BE REPEATED IN REPORT

TECHNICAL REPORT MUST CONTAIN INTERPRETATION, CONCLUSIONS ETC.

>

uuUin*±*

9005 UJ

V)

S2 */)f* iCD -J

3 gType of Survey(s) Airborne E.M. /MAG. /VLF-EM.Township or Area Summers and McComber Twos.Claim Holder(s) Pancontinental Mining (Canada) Ltd. f

365 Bay Street. Ste. 600. Toronto. Ontario^—————...Survey Company Dighem Ltd.——-———.-^—.———————--—

Author of Report Z. Dvorak^^-—————————————.—Address of Author P. O. Box 178 f Ste. 7Q10 f First Canadianr* - r. rt?oronto * Ontario n/c/oi 10 IL 7oiCovering Dates of Survey....:________17/6/81-19/6/8]i———

(linecutting to office)

Total Miles of Line Cut N/A1———^—...———.—————.^

SPECIAL PROVISIONS CREDITS REQUESTED

ENTER 40 days (includes line cutting) for first survey.ENTER 20 days for each additional survey using same grid.

Geophysical—Electromagnetic.—Magnetometer-——Radiometric———Other—————

DAYS per claim

Geological.Geochemical.

AIRBORNE CREDITS (Special provision credits do not apply to airborne turveyi)"~" ———————————————— 'M?gnptnmptpr 40 F.Wtrnmagnefir 40 ——— Ra

VT "F /FM diometric

(enter days per claim)

July 28. 1981 SIGNATURE:.Author of Report or Agent

Res. Geol.. .Qualifications. c?.

Previous Surveys File No. Type Date Claim Holder

MINING CLAIMS TRAVERSED List numerically

(number)

ce,

I

TOTAL CLAIMS &L

837 (5/791

GEOPHYSICAL TECHNICAL DATA

GROUND SURVEYS — If more than one survey, specify data for each type of survey

Number of Stations —————————————————————————Number of Readings — Station interval!____________________________Line spacing —.———.Profile scale .-----—-—-^--^---—-——-——---——---——.^.—.---.———.-.—^—^^—Contour interval.

Accuracy — Scale constant.Instrument.

Diurnal correction method ————— Base Station check-in interval (hours). Base Station location and value ___

ELECTROMAGNETIC

Instrument

Coil configurationCoil separation

AccuracyMethod: Frequency

Q Fixed transmitter D Shoot back D In line O Parallel line

(specify V.L.F. station)

Parameters measured.

Instrument.Scale constant

Corrections made.^

o Base station value and location

Elevation accuracy.

y,ot— 4

< N(—(

C*<U

2CL,

QWyDQ •^a

I*

Hl-*4>HH

H00HM*O)wtt!

Method D Time Domain D Frequency Domain

Parameters — On time Frequency

-Offtimp Range ......

— Delay time

— Integration time

Pnwer

Electrode array -. . , .

Electrode spacing ..-.- - ...- ... , ....

Type nf elertrnrle

SELF POTENTIAL Instrument——————————————————————————————————————— Range.Survey Method ———————————————————————————————————————————

Corrections made.

RADIOMETRIC Instrument————Values measured.Energy windows (levels)_______________________________,-—————Height of instrument____________________________Background Count. Size of detector———————————.^—^—.—.—————^^^—.—..——.——-....—.—

Overburden _______________________________________________.(type, depth - include outcrop map)

OTHERS (SEISMIC, DRILL WELL LOGGING ETC.) Type of survey—^——————————————^——-.Instrument ——-.—————-—.-.—..——^^—————— Accuracy.———————————————————^^—^—Parameters measured.

Additional information (for understanding results).

AJRBQRNE SURVEYSType of siirvpy(s) Electromagnetic, Magnetic, VLF-EMInstrument(s) EM - Sonotek PM11-S010, MAG-Snnntek SDS 1200, V\.T - HF.R7. TOTF.M 1A.

(specify for each type of survey)

ArrnraryEM - 0.2ppmybit r MAG - one gamma/bit f VLF - Q.1% hit.^.^.,..—^———.(specify for each type of survey)

Aircraft nspH Alouette II helicopter.————^^^————^—.^-———..—————.—^.—

Sensor altitude EM - 43m, MAG. 58m, VLF-EM 65m.——.-———-^^—^——.--^.-——— Navigation and flight path recovery mpthnd Analog and digital profiles used.—-—-——

Aircraft altitnHp Not stated.________________________Line Sparing 3QOm.Miles flown over total area 129 Line km. Q'O. l___________Over claims only 50.5 Line km. 3\.H

GEOCHEMICAL SURVEY - PROCEDURE RECORD

Numbers of claims from which samples taken.

Total Number of Samples. Type of Sample.

(Nature of Material)

Average Sample Weight——————— Method of Collection————————

Soil Horizon Sampled. Horizon Development. Sample Depth———— Terrain————————

Drainage Development———————————— Estimated Range of Overburden Thickness.

ANALYTICAL METHODS

Values expressed in: per cent p. p. m. p. p. b.

a aa

Cu, Pb,

Others_

Zn, Ni, Co, Ag, Mo, As.-(circle)

Field Analysis (~Extraction Method. Analytical Method. Reagents Used——

Field Laboratory AnalysisNo. ^^———————

SAMPLE PREPARATION (Includes drying, screening, crushing, ashing)

Mesh size of fraction used for analysis——^—

Extraction Method. Analytical Method . Reagents Used——

Commercial Laboratory (. Name of Laboratory— Extraction Mftthnri

Analytical Method—— Reagents Used ————-

.tests)

.tests)

.tests)

General. General.

* MINING CLAIMS TRAVERSED

T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.

465854465855506598506599506600506601506602506603506604506605506606506607506608506609506610506611506612506613506614506615506616506617506618506619506620506621506622506623506624506625506626

T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.T. B.

506627506628506629506630506631506632506633506634506635506636506637510708510709510710510711510712510713510714510715510716510717510718518068518069518070518071518072519883538483

33

-f

LOC

AT

ION

M

AP

B 8

"O C

Sca

le

i 250,0

00

42

E1

2S

W8

0a

i 2.4

074

MC

CO

MBE

R2

00

DlG

HE

M"

SU

RV

EY

BEAR

DM

OR

E A

RE

A,

ON

TAR

IO

ELE

CT

RO

MA

GN

ET

ICS

FOR

PA

NC

ON

TIN

EN

TAL

MIN

ING

C

ANAD

A LT

D.

SC

AL

E

l :

10

,00

01/2

l K

ilom

etre

s1 —

——

——

— 4

1 ——

——

——

l l —

——

——

— 1

1/4

0

ZtA

lM

toc^rio

MS

.

~\

— —

— i —

—

" —

— r

li —

——

——

——

——

——

——

1/4

1/2

M

iles

sW

tv//

O

A/

r//

/^

MflP

Fli

gh

t M

n* Fid

uci

ols

and

num

bers

AN

OM

ALY

EM

G

RAD

E M

HO

G

RA

DE

S

YM

BO

L R

AN

GE

e 0

sa

lo

o5

-9-

50

— 9

9

4 0

2

0—

49

3

O

10 —

19

2 Q

5—

9

1 O

S

S4

X

Pos

sibl

e co

nduc

tor

iden

tifie

r —

*-C

—33

-* —

— m

ho

valu

e

y

^v

r In

phas

e an

d - —

——

-Q

uadr

atur

e of

D

epfh

u

S

lond

ard

CO'1

grea

ter

inon

'*

flre

oter

th

en

. 5

0 ft.t

5

PI"

"

: 100 f

nt

" 10

PEm

-.

ISO

fe.t

"-

1S

ppm

i ,n

rn..

t -.

- 20""

"

ppm

va

lues

fo

r oil

coils

, an

d 'o

r co

nduc

tor

dflp

tM

— -^

-—

Con

duct

or

ox-s

S P

roba

ble

surf

ace

resp

onse

S?

Pos

sibl

e su

rfac

e re

spon

se

L P

roba

ble

li"*

l pow

er ,

tele

phon

e ,

pipe

, or

fence

)

L?

Pos

sibl

e lin

e

7 Q

uest

iona

ble

anom

aly

O

App

aren

t th

ickn

ess

^ 1

0 m

>

Dip

10

QJ

Dire

ct m

agne

tic c

orre

latio

n of

100

gom

mos

DlG

HEM

ano

mal

ies

ore

divi

ded

into

six

grad

es o

f co

nduc

tivity

-

thic

knes

s pr

oduc

t Th

is

prod

uct

in

mho

s is

'he

reci

proc

al o

f re

sist

ance

m

ohm

s Th

e m

ho

is a

mea

sure

of

cond

ucta

nce,

and

is

a ge

olog

ic p

aram

eter

. M

ost

swam

ps

yiel

d G

rade

1

anom

alie

s bu

t hi

ghly

con

duct

ing

cloy

s ca

n gi

ve G

rade

2 o

nom

atie

s.

The

mul

ti -

coil

anom

aly

shap

es o

ften

allo

w s

urfa

ce c

ondu

ctor

s lo

be

rec

ogni

zed,

a"d

Ihe

se u

re i

ndic

ated

by

the

lette

r S

on t

his

map

. Th

e re

mai

ning

Gra

de 1

and

2 a

nom

alie

s co

uld

be w

eak

bedr

ock

cond

ucto

rs.

The

high

er g

rade

s in

dica

te

incr

easi

ngly

hi

gher

co

nduc

tanc

es

Exam

ples

; The

ore

bod

ies

ot t

he

Mag

usi

Rive

r ca

mp

yiel

d G

rade

4 a

nom

alie

s, w

hile

M

atta

bi

and

Whi

stle

gi

ve

Gra

de

5.

Gra

phite

and

sul

phid

es c

on s

pan

all

grad

es b

ut,

in t

his

surv

ey

area

, fie

ld w

ork

may

sho

w t

hflt

the

diffe

rent

gra

des

indi

cate

di

ffere

nt t

ypes

of

cond

ucto

rs.

The

actu

al m

ho v

alue

is

plot

ted

besid

e th

e EM

qr

ade

sym

bol.

The

lette

r is

the

anom

aly

iden

tifie

r. Th

e ho

rizon

tal

rows

of

dol

s in

dica

tean

omal

y am

plitu

de o

n th

e fli

ght

reco

rd,

and

the

verti

cal

colu

mn

give

s th

e es

timat

ed d

epth

. Th

is

dept

h m

ay

be u

nrel

iabl

e be

caus

e th

e st

rong

er p

ort

of t

he

cond

ucto

r m

ay

be d

eepe

r or

to

one

side

of

the

flig

ht l

ine,

or

beca

use

of a

..h

allo

w d

ip o

r co

nduc

tive

over

burd

en

effe

cts.

DlG

HEM

map

s ar

e de

sign

ed t

o pr

ovid

e a

corr

ect

impr

essi

on o

f co

nduc

tor

qual

ity b

y m

eans

of t

he c

ondu

ctan

ce

grad

e sy

mbo

ls. T

he

sym

bols

con

sta

nd a

lone

with

geo

logy

whe

n pl

anni

ng a

fol

low

up

prog

ram

. Th

e ac

tual

m

ho

valu

es a

re

plot

ted

for

thos

e wh

o w

ish

quan

titat

ive

data

. Th

e an

omal

y pp

m a

nd d

epth

are

ind

icat

ed b

y in

cons

picu

ous

dots

whi

ch s

houl

d no

t di

stra

ct f

rom

the

con

duct

or

patte

rns,

whi

le

bein

g he

lpfu

l to

thos

e wh

o w

ish

this

inf

orm

atio

n.

The

map

pro

vide

s on

int

erpr

etat

ion

of a

ll co

nduc

tors

in

term

s of

le

ngth

, st

rike

dire

ctio

n, c

ondu

ctan

ce

and

dept

h. T

he

accu

racy

is

com

para

ble

to a

n in

terp

reta

tion

from

a g

roun

d EM

Sur

vey

havi

ng I

he s

ame

line

spac

ing.

JOB

153,

JU

LY 1

981