RPT ON A GEOTEM EM & MAG SUR RHODES VMS …...Rhodes VMS Project located in Rhodes Township approximately 60 km northwest of Sudbury, Ontario. The objectives of the survey were to

41P14NW1013 Z . 1 4199 RHODES

l l l l1 2.14199l A GEOTEM EM AND MAGNETIC SURVEY

RHODES VMS PROJECTl RHODES TOWNSHIP, ONTARIO B FOR FALCONBRIDGE LIMITED

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l MINING LANDS SECTION

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lDistribution: File: 6039

l 4 - Falconbridge Limited, Falconbridge, Ontariol - CGI Controlled Geophysics Inc., Mississauga, Ontario May, 1991

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EXECUTIVE SUMMARY

During the period December 15 to 27,1990 a combined airborne magnetic and GEOTEM EM survey was carried out by CGI Controlled Geophysics Inc. for Falconbridge Limited over their Rhodes VMS Project located in Rhodes Township approximately 60 km northwest of Sudbury, Ontario. The objectives of the survey were to map in detail the magnetic and electromagnetic responses to obtain an improved geological interpretation, to identify targets of potential economic value, and to relate the new information to that obtained from prior geological and geophysical surveys located in the same area. Including tie-lines, a total of approximately 260 line kilometres were flown.

The geophysical parameters measured during flight were total magnetic field (at l sample per second) and 12 electromagnetic channels representing the GEOTEM transient response (at 6 samples per second). Data compilation carried out during early 1991 consisted of flight path recovery, electromagnetic data processing, preparation and plotting of total magnetic field data, and calculation and plotting of first vertical magnetic derivative.

As interpretation aids, maps of processed GEOTEM channels were plotted in coloured plan profile format to show all EM responses in the survey area. The total magnetic field and a computed first vertical derivative were contoured in blackline and colour-fill and presented. Finally, maps of Of/TPJTTPseudoChannel amplitude were prepared to show the time constants and response strength of conductors in the area.

This report presents a logistical account of the survey, describes the products produced, and provides a full interpretation of the results. Of a total of 8 discrete conductive trends and areas, 4 have been recommended for high-priority ground follow-up. All targets are listed with ratings in Table 8. A detailed program of ground geophysics is recommended to pinpoint targets before drilling, especially in areas where complex structures appear to be present and conductor axes were not uniquely resolvable.

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EXECUTIVE SUMMARY

INTRODUCTION

SURVEY AREA DESCRIPTION

FIELD WORK

3.1 Survey Specifications3.2 Survey Operations

DATA COMPILATION AND PRESENTATION

4.1 Right Path Recovery4.2 Total Magnetic Field Preparation and Presentation4.3 Magnetic First Vertical Derivative Preparation and Presentation4.4 Electromagnetic Data Preparation and Presentation4.5 OUTPUT EM Processing and Preparation4.6 Data Archiving

INTERPRETATION OF RESULTS

5.1 Introduction5.2 The Geophysical Responses over the Rhodes VMS Project5.3 Interpretation - Rhodes VMS Project

CONCLUSIONS AND RECOMMENDATIONS

STATEMENT OF QUALIFICATIONS

TablesFigures

Appendix A - Geoterrex Ltd. Logistics and Processing Report

Appendix B - Flight Logs

Appendix C - Anomaly Listing

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LIST OF FIGURES

Figure l Survey Area Location MapFigure 2 GEOTEM® Principles of OperationFigure 3a GEOTEM® Channels l through 6 HistogramsFigure 3b GEOTEM® Channels 7 through 12 HistogramsFigure 4 OUTPUT Processing PrinciplesFigure 5a Thin PLATE Anomaly Observed Flying Down Dip of 60OFigure 5b Thin PLATE Anomaly Observed Flying Up Dip of 60O

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LIST OF TABLES

Table l Survey Flying SpecificationsTable 2 Project DeliverablesTable 3 GEOTEM® EM Receiver Window PositionsTable 4 Levelled GEOTEM® Channel Histogram AnalysisTable 5 Analogue Chart Record FormatTable 6 OUTPUT Processing SummaryTable 7 Line Archive Data FormatTable 8 Summary of Targets for Follow-up

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INTRODUCTION

This report describes the execution and results of a combined GEOTEM* EM and magnetic survey carried out by CGI Controlled Geophysics Inc. from December 15 to December 27, 1990.

The survey instrumentation and layout were chosen by Falconbridge and Controlled Geophysics personnel to maximize the ability to detect conductors of potential economic value and to use the electromagnetic data in a mapping mode to compliment the magnetic data mapping abilities. The EM mapping is achieved by presenting the conductivity distribution in the area as maps of apparent time constant derived from the OUTPUT processing technique developed by C. Vaughan.

The data were acquired via a sub-contract to Geoterrex Ltd. of Ottawa, Ontario who were also responsible for flight path recovery and levelling of the total magnetic field. Calculation of first vertical derivative and blackline and colour-filled contour plotting of both magnetic products were carried out by Controlled Geophysics. The electromagnetic data were processed and presented by Controlled Geophysics.

This report presents a full interpretation of the results along with supporting map products and recommendations for follow-up.

2. SURVEY AREA DESCRIPTION

The Rhodes VMS Project survey area is located in Rhodes Township some 60 kilometres north-northwest of Sudbury, Ontario (See Figure 1), and is encompassed within the following geographic co-ordinates:

LONGITUDE LATITUDE

0810 27' W 460 53' N 0810 19' W 460 58' N

The co-ordinates used on the maps are expressed in metres north of the Equator and east of a false easting located 500,000 metres west of 81O W longitude for the local UTM grid zone 41- 1/14. The UTM limits for the Rhodes VMS Project are:

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EASTING (m) NORTHING (m)

465,000 5,191,000477,000 5,201,000

According to Ontario Geological Survey Map 2413, the geology of the area consists primarily of felsic intrusive and migmatitic granodiorite and quartz monzonite rocks with diabase dikes along the northeast side of the survey block grading to intermediate to felsic metavolcanics, amphibolites, and metasediments as one travels south and west. Sudbury type breccias have been mapped within the mafic metavolcanics along Bennet Lake. Northwest trending iron formations have been mapped within the mafic metavolcanics west of Richardson Lake. Major faulting and lineaments have been mapped in a variety of strike directions, with NW-SE predominant.

The survey area is quite rugged, with topographic relief occasionally exceeding 250 feet from lake surface to hill top. There is very little wetlands terrain.

Cultural responses are limited to roads and other features associated with mineral deposits and showings, especially west of Richardson Lake and near Sandfly Creek.

3. FIELD WORK

3.1 Survey Specifications

The survey specifications were set jointly by Controlled Geophysics and Falconbridge Limited based on a detailed knowledge of the GEOTEM® system, the project objectives, and some a priori knowledge of the regional geological setting.

The nominal line spacing of 200 metres and line direction of 25072050 were chosen by Falconbridge Limited to map the property in sufficient detail to resolve the anticipated structures. A series of tie-lines oriented 115072950 were also specified.

The flying specifications in Table l were commensurate with current standards except for a tightening of the navigation specification to cover altitude as well as horizontal positioning. See Section 4.4 for a description of the GEOTEM® system configuration.

3.2 Survey Operations

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survey operations are described in the Geoterrex Limited Logistics and Processing Report in Appendix A of this report. A Controlled Geophysics geophysicist visited the survey base of operations in Sudbury to monitor survey performance and data quality. The flight logs are presented in Appendix B of this report.

4. DATA COMPILATION, PROCESSING, AND PRESENTATION

This section covers the preparation and presentation of the products listed in Table 2. Each product has been presented on one map sheet at a scale of 1:10,000.

4.1 Flight Path

The flight path recovery (described in Appendix A) was carried out by the airborne sub contractor using Doppler and Global Positioning System (GPS) data to assist visual navigation. The final flight path has been presented in one sheet on a photomosaic base at a scale of 1:10,000. Each line is labelled and annotated with fiducial ticks every 100 fids (10 seconds) and fiducial labels every 500 fids (50 seconds). The direction of traverse is indicated by an arrow at the beginning and end of each line. On all maps, a network of registration cross hairs has been plotted at 1,000 m intervals.

4.2 Total Magnetic Field Preparation and Presentation

The total magnetic field measured during the survey was corrected for diurnal variations and levelled by the airborne sub-contractor. See Appendix A for details. These data were delivered to Controlled Geophysics as both a final grid archive and a line archive. The total magnetic field grid was then contoured at 5 nT (gamma) intervals and presented as blackline contours on a photomosaic base at 1:10,000. The total magnetic field grid has also been colour-filled at 5 nT and presented with blackline contours and flight path in one sheet at 1:10,000. The digital grid was imaged, including shadowing, with RTI-CAD on a workstation. The RTI-ready file has been supplied on diskette.

On the re-plotted analogue chart, the total magnetic field channel is plotted in coarse and fine scales, both bolded for ease of use. A message at the start and end of each line indicates the absolute total field value. The magnetic lag of 0.67 seconds (4 samples) has been applied.

43 Magnetic Vertical Gradient Preparation and Presentation

The magnetic first vertical derivative (or gradient) operator serves to accentuate shallow magnetic sources and magnetically defined contacts and to more clearly resolve closely spaced anomalies. The magnetic first vertical derivative O nT/metre contour defines contacts between

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|ore susceptible rocks (having positive vertical gradients) and less susceptible rocks (having negative vertical gradients).

The first vertical derivative of the total magnetic field was calculated from the total magnetic field grid and then blackline contoured at 0.05 nT/metre intervals and presented on a photomosaic base at 1:10,000. It has also been colour-filled at 0.05 nT/metre and presented in combination with blackline contours and flight path in one sheet at 1:10,000. During interpretation, the digital grid was imaged, including shadowing, with RTI-CAD on a workstation. The RTI-ready file has been supplied on diskette.

AA Electromagnetic Data Preparation and Presentation

The raw GEOTEM® data were compiled and processed at Controlled Geophysics during early 1991. Before any presentation or OUTPUT processing could be carried out, the data needed to be processed to remove noise from known non-geological sources. This section describes each of these procedures.

Figure 2 presents the principles of operation of the GEOTEM® system. When a conductor is nearby, the receiver measures a transient waveform produced by the decay of the induced secondary field from that conductor. During flight, a set of channel amplitudes measured in a number of time slices through the transient are plotted vs time on analogue chart records. The amplitude of the response grows as the aircraft approaches the conductor and returns to zero or background levels as the aircraft departs. The detailed manner in which the amplitudes vary in the interim (including possible zero crossovers and nulls) provide source type and geometry information. In the GEOTEM® system, a set of channel amplitudes are recorded six times per second corresponding to roughly one transient every 10 metres.

In the GEOTEM® receiver there are 20 channels available to represent the transient waveform. Twelve of these are positioned at equal time intervals throughout the off-time to obtain a true representation of the transient waveform. The other eight channels are used to monitor the GEOTEM® response throughout the on-time. Additional channels record the primary field at the towed bird and the power line noise. The position and widths for the channels are summarized in Table 3.

The raw GEOTEM® data were loaded from 9-track tape and plotted on large scale plots showing selected channel amplitude profiles. The high rate of sampling in the raw GEOTEM® data permits spherics to be edited by statistical means, thus preserving the fidelity of the ground responses. The GEOTEM® data are calibrated during flight and require no post- survey calibration. Channel levelling errors due to a small amount of system drift must be trapped and adjusted before OUTPUT processing.

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has been carried out using a combination of statistical means and the end-of-flight calibration sequences that appear on the raw analogue charts. The end-of-flight base levels were measured and subtracted by applying a linear correction to each EM channel across the duration of the flight Where non-linear drifts were present, the same type of levelling was carried out using shorter, linear drift segments.

The statistical characteristics of the levelled EM data were then examined using a histogram of amplitude occurrences computed for each channel. The results are presented in Figure 3. The range of amplitudes available in the histograms is -100 to 4-1,900 ppm. Each histogram contains the same area so that amplitudes falling within a close range of O will appear narrow and peaked while channels with more variability in amplitude produce broad, flat histograms. Where a number of amplitudes are counted above 1,900 or below -100 ppm, these counts are collectively plotted at their respective limits, producing a single spike there.

The key elements of the histograms are summarized in Table 4 where the absolute minimum and maximum value for each channel are presented along with the histogram peak amplitude and the first and second standard deviations above and below the peak. The peak amplitude provides the average amplitude in that channel, which for late channels is usually the zero or base level. For early channels it is the average ground response in that channel. Levelling errors appear as a shift of the distribution from zero and/or a break in the monotonic decrease of average channel amplitude expected from early through late time and/or a general broadening of the histogram. The standard deviations in the late time channels provides an estimate of the measured noise level in the data which is more quantitative than values based on an "eyeballed" noise level from analogue chart.

The 1.5 second time constant filter used for display during flight is adequate for the real-time analogues, but not for processing and interpretation as it phase-shifts the anomalies and degrades important anomaly nulls and zero crossings. For post-flight processing and presentation, adaptive spike rejection and a symmetric low-pass filter was used to reduce noise while preserving the anomaly peak shapes and locations.

The EM data are presented in profile form on the re-plotted analogue chart records. From top to bottom, the various plotted parameters are summarized in Table 5. The zero locations and scales for each channel are printed in the Configuration Table at the start and end of each roll. The zero position for each profile is measured in centimetres from the top of the chart downward. The horizontal scale is time based, but it represents approximately 1:20,000 scale on the ground. Each line number is clearly labelled, as are fiducial numbers matching the map products.

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nominal value for the primary field measured at the receiver is l million ppm. The cyclic variation in it, especially at the start of each line, is caused by the bird swing as the aircraft settles onto course after the turn.

The altimeter channel nominal value is 120 m (394 ft) aircraft terrain clearance. The nominal bird terrain clearance is about 64 m (210 ft).

The power line channel along the bottom of the chart exhibits a peak when 60 Hz signals are detected

The twelve GEOTEM® channels have been plotted at a scale of 400, 200, and 100 ppm/cm for Channels 1-4, 5-8, and 9-12 respectively. Within each commonly scaled group of channels, the zero levels are a constant 0.5 cm apart. Due to the towed-bird configuration of the fixed-wing AEM system, the recorded EM channels are lagged in time by 4 seconds (40 fiducials) compared to the aircraft location. On the newly generated analogue chart records, the EM and magnetic data lags have been removed. All lags are present on the original aircraft chart records.

Levelled original GEOTEM® Channels 2 and 5 have been plotted in plan profile at 1:10,000 scale and 100 ppm/cm vertical scale. The EM data lag has been removed.

4.5 OUTPUT EM Processing and Presentation

The filtered and levelled GEOTEM® data were further processed using Controlled Geophysics' O UTPUT program, which generates apparent time constant and initial amplitude from a transient measurement. Every point in the survey consists of a sampled transient yielding 12 channel amplitudes. The measured GEOTEM® transient resembles an exponential decay function with a characteristic initial amplitude and time constant. An exponential decay model is determined from each transient in the survey using a weighted least squares algorithm. Figure 4 presents the channel amplitudes plotted as symbols with the fitted exponential running smoothly through them.

The parameters generated by the OUTPUT program are the initial amplitude of the exponential decay in ppm, the time constant of the exponential in microseconds (/MS), and the normalized error in fit of the exponential to the measured EM channels, called Fit Index. The Fit Index is a function of how closely the fitted data match the observed and a function of the number of channels used for that fit. The closer the fitted transient matches the measured data and the more channels used, the larger the Fit Index value will be, to a maximum of 100.

In general the depth and orientation of a conductor affects the initial amplitude of the anomalous response while the conductivity and spatial extent of the conductor is proportional

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to the apparent time constant. The transient recorded from an ideal conductor, such as a well- connected deposit of massive sulphides at shallow depth would exhibit a strong initial amplitude and a slow decay because of its large apparent time constant value. The manner in which the initial amplitude changes along the line indicates the general shape of the body that is producing the response (i.e., a thin plate, a horizontal ribbon, or a sphere) and its orientation and depth.

The transient recorded from a surficial conductor, such as a lake bottom or swamp would exhibit a very high initial amplitude, because of its relatively close proximity to the AEM system, and a rapid decay because of its much smaller apparent time constant value. For areas of extensive continuous cover, the observed time constant may not vary much while the initial amplitude changes as the aircraft and/or towed bird change geometry. This phenomena produces "false" anomalies on traditional interpretation maps and chart records, but not on OUTPUT maps that key on time constant variations. Time constant can vary even when no anomaly peak is observed, as when a survey is flown sub-parallel to conductor strike or when bedrock conductor responses are embedded within larger surficial responses. These targets may be overlooked during standard compilation procedures that place emphasis upon anomaly peaks.

Where data are noisy or of low amplitude or where the transient decays very quickly, only the first few channels are reliable to fit an exponential to. Normally, a minimum number of 3 channels is specified to obtain a reliable fit. In more resistive portions of the survey, the minimum number of channels may not be available, so OUTPUT reports no fits there. The OUTPUT processing results are summarized in Table 6 where the percentage of transients successfully fitted by OUTPUT'is provided, along with what number of time constants in a given range were fitted at different Fit Index values.

In the Rhodes VMS survey data, approximately 796 of the 27,255 transients were successfully fitted. Of these, approximately 9596 had a Fit Index of 15 or greater.

In lieu of initial amplitude, a PseudoChannel amplitude is used on the maps and on the final analogue chart records. The PseudoChannel presentation is a useful format to express the transient information. It is defined as the amplitude of the fitted exponential after it has decayed from its initial amplitude for a specified period of time. Since each GEOTEM® time gate represents a fixed delay time following the transmitter shut-off, one can use the same delay time to compute a corresponding PseudoChannel using the formula:

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Pi ~

where Pj is the PseudoChannel i amplitude,AO is the fitted initial amplitude,tj is the specified Channel i delay time,c is the fitted time constant.

Selecting a small delay time t will result in large PseudoChannel amplitudes for all responses in the survey. Using a large delay time produces a map where only the most conductive responses have any appreciable amplitude. For the Rhodes VMS Project survey, maps of PseudoChannel 2 and 5 (delay times of 547 and 1,015 /xs respectively) have been prepared to show a range of conductivities.

On the OUTPUT PseudoChannel maps the processed data are presented in a shaded plan profile format where the height of the profile at each location is the PseudoChannel amplitude and the colour is its time constant. The smallest time constants are given cool colours and the longest are given warm colours. All data above Fit Index of 15 have been presented. The EM lag has been applied.

The selection and presentation of EM intercepts is described in Section 5.1 below.

4.6 Data Archiving

The final located line data have been archived in ASCII form on 9-track tape. The final gridded data have been delivered in Geopak RTI-ready on floppy diskettes. Table 7 provides the file format for the digital line archive.

5, INTERPRETATION OF RESULTS

5.1 Introduction

The following geophysical interpretation of the survey results reflects the biases of the interpreter. It was prepared based on the products of the survey and a limited knowledge of the geological setting. The interpretation may be refined through the addition of ground control and modelling.

In general, an optimum bedrock conductor should have a large time constant and a strong initial amplitude. The anomaly profile will show a fairly narrow cross-section (a few hundred metres peak half width amplitude) if it is caused by a discrete, steeply-dipping bedrock conductor such as a graphitic horizon or by massive sulphides. Anomaly half-width normally

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with increased depth of source. Broader anomalies can be caused by regional changes in basement lithology or widespread flat-lying conductors including swamps, lake- bottom sediments, and glacial or fluvial clays.

Power lines, buildings, railways, and other cultural features can create anomalies that resemble bedrock conductors in time constant and shape; however, they are often readily identified by a signal in the power line monitor (HYDR on the chart records) or by visually inspecting the photomosaics and videotapes for signs of man-made structures. Due to their 2-D nature, power line responses are strongest when the survey is flown normal to their strike and may give no response at all when the survey is flown sub-parallel to them. The GEOTEM® system employs synchronous detection to reject 60 Hz (and harmonics) signals, but DC power sources cannot be rejected using that principle because they have a wideband frequency content. Where EM anomalies coincide with power line monitor response and exhibit a high degree of correlation with magnetics, but show no visual evidence on the ground, they are treated as possible geological conductors since active power lines can induce current flow in geological conductors.

Weaker conductors with short time constants are often good targets for precious metal exploration, especially where they have good correlation with favourable magnetic or geological models. Sometimes, such responses are similar in character to surficial responses of finite extent such as a narrow stream bed. In situations where an above average time constant is consistently detected (i.e., 150 ju-s vs 100 ^s) within a widespread area of conductive cover, there may be an underlying bedrock conductor. It might also indicate a thickening of the surficial conducting layer, since a thicker layer supports a larger induced eddy current pattern which would produce a larger apparent time constant. Magnetic data are normally used to corroborate the authentic bedrock responses.

To be sure of catching even the subtle responses, the interpretation was carried out with reference to the analogue charts, OUTPUT derived time constants and PseudoChannel maps, contoured maps of total magnetic field and calculated first vertical derivative, and the photomosaics of the terrain.

The interpretation maps have been generated to present both the picked anomaly peaks and the interpreted conducting zones. All EM intercepts presented on the interpretation maps were hand-picked off the field analogue charts by a geophysicist. The location was tied to a peak (or shoulder) in a middle channel. Wherever possible, anomalies with only a Channel l response were not picked to avoid an excessive number of "bird-motion" responses.

The selection of anomalies was refined following preparation of the OUTPUT time constants and new analogue charts. Shifted by the lag amount, they have been plotted as symbols on the flight path over a photomosaic base map. The circular symbols show peak position and are of

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Aline thickness weighted according to the fitted apparent time constant. An anomaly designation letter beside each circle indicates which anomaly on the line it is, i.e., A, D, or N. Also posted are the GEOTEM® Channel 5 amplitude in ppm and the computed time constant (referred to as Tau) in microseconds. The former gives anomaly strength and the latter is proportional to conductivity. Occasionally, the symbol is annotated with a zero valued time constant where the anomaly has had too few channels to obtain an OUTPUT fit. These anomalies may be thought of as marginal. EM intercepts which have OUTPUT fit indices below a specified threshold are plotted with an asterisk to show the degree of uncertainty in the time constant value.

The EM intercepts were overlain upon maps of raw data in plan profile, the OUTPUT Pseudocannel maps, and magnetic total field and magnetic first vertical derivative maps and checked for position and line-to-line correlation. Finally, axes were interpreted and sketched in. Where an axis was not obvious for a conductive area, the area was outlined. A solid line indicates a definite axis while a dashed line implies tentative line-to-line correlation and/or uncertainty in location. Where possible, interpreted geological contacts and structures are indicated.

The location of the top of the conductor in relation to the anomaly symbol depends on the anomaly shape and the flight direction. The profiles in Figure 5 are those that would be seen from flying over a thin plate-like body in opposite directions. Two peaks are observed when the aircraft flies up dip. The plate top lies between them. One peak is observed in the other direction. The plate top lies just before the peak. These rules were used to position the axes. Where the anomalies are all attributed to a conductive overburden response, a long dashed line has been used to encircle the area. Where a bedrock conductor has been interpreted within such an area, the axis is drawn as well. The OUTPUT information allows variation of conductivity along strike to be monitored.

Where residual noise exists in the data, an occasional spurious OUTPUT anomaly may occur. Some of these have moderate or high time constants on the maps. Each of these has been double-checked and, if truly spurious, is not recommended for follow up. The analogue chart may be used to directly compare the OUTPUT to the original data. Often, the OUTPUT anomaly location will be different from the EM peak recorded from the original analogue charts. This shift occurs when peak migration (with channel) is present and a late PseudoChannel is used or when the original pick was distorted by surficial response.

Passive cultural conductors, such as fence lines and railway tracks, often produce a real-looking anomalies with no evidence of culture in the power line monitor on the analogue chart. These responses have generally been included on the EM maps where their source is readily apparent from the photomosaic base. Active cultural conductors, such as power lines, show activity in the power line channel. These have not been picked and seldom have an EM intercept on the

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tf^terpretation map. A certain amount of inconsistency is unavoidable since cultural responses vary widely with strike direction compared to flight direction.

The major conductive trends and areas in the survey block have been given an alpha-numeric name using the format "Rx" where x= l, 2, 3, etc., e.g., "R2". The named anomalous trends are summarized in Table 8. The individual anomaly peaks are tabulated in an appendix where they are grouped by line number and listed with UTM position, fiducial, altimeter, magnetics, GEOTEM® Channel 2,5, 8, and 11 amplitudes, OUTPUT initial amplitude, time constant, and fit index.

The individual anomalous trends and areas are discussed in the following sections. Related ones are discussed together. In some cases, estimates of dip and depth are provided. Note that all anomalies discussed are recommended for follow up with ground geophysics unless specifically noted otherwise.

5.2 The Geophysical Response over the Rhodes VMS Project Area

The Rhodes VMS Project Area exhibits a wealth of magnetic responses, but only limited electromagnetic response. The following are some general observations.

The strongest magnetic responses occur within the mafic metavolcanics, but the areas of high magnetic intensity do not correlate with mapped distribution of those rock units. A large, response in the west central portion of the survey block correlates with iron formations reported on OGS Map 2413. A smaller magnetic feature of similar intensity occurs in the east central portion of the survey block. This latter corresponds with a reported mineral occurrence, and may represent more metasediments or iron formation. A circular magnetic high occurs 500 metres west of the western end of the eastern magnetic high. The intervening low corresponds to Richardson Creek. As the reported rock types change across Richardson Lake, there may be a NW trending contact or fault which has split the magnetic structure. Strong electromagnetic responses were recorded in the same area.

The background electromagnetic response in the survey is essentially nil. The conductors have produced moderate amplitude, low to moderate conductivity anomalies between the two major magnetic highs and south of the eastern magnetic high, and near the magnetic high over North Lake. Most of the EM responses exhibit broad profile shape and negative peak stagger, suggesting that the sources are either wide and vertical or flat-lying.

53 Interpretation - Rhodes VMS Project Area

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R2

Conductor R2 consists of broad, poor quality (weak) EM responses over an E-W trending magnetic response best defined on the first vertical derivative map. The reverse peak stagger has been attributed to a wide or flat-lying source. It is rated moderate priority for ground follow-up.

R3

Conductor R3 consists of a series of large amplitude, moderate time constant EM responses located due south of a major magnetic high zone. The complex distribution of anomalies are produced by multiple bodies or a single wide or flat-lying source. The area is rated high priority for ground follow-up.

R4

Conductor R4 is a 1.5 km long series of weak, low conductivity EM responses with positive peak stagger and some magnetic association. It is rated low priority for ground follow-up.

R5

Conductor R5 is dominated by a strong, high time constant EM intercept A on Line 12901. It and additional responses in the area appear to flank a circular magnetic high north of Bennet Lake. Conductor R5 is rated high priority for ground follow-up.

R6

Conductor R6 consists of EM intercept B on Line 13101 and C on Line 13001. Response B has strong amplitude and high conductivity based upon time constant and is located at the western terminus of a magnetic rock unit. The conductor is on strike with the possible contact beneath Richardson Lake. There is a stream in the area, but the B response is better than average for a surficial source. Conductor R6 is rated high priority for ground follow-up.

R7,R9

Conductor R7 consists of strong, high time constant responses. The complex pattern of profiles may represent multiple flat-lying or wide vertical source conductors. The area is rated high priority for ground follow-up. Conductor R9 is a two-line EM response at the intersection of a small E-W trending vertical magnetic derivative anomaly and the eastern edge of the large magnetic high. It is rated moderate priority for ground follow-up, especially on Line 11901.

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Conductor R8 consists of a series of weak EM responses which correlate with a NNW trending vertical magnetic derivative high along the west edge of Richardson Lake. It is rated moderate priority for ground follow-up since it may represent mineralization on a geological contact. The positive peak stagger suggests a vertical thin source.

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CONCLUSIONS AND RECOMMENDATIONS

The combined airborne GEOTEM® electromagnetic and magnetic survey in the Rhodes VMS Project survey area has detected many magnetically-defined structures and several conductive trends within a resistive background. Several weak conductors were confirmed by OUTPUT processing. The combination of original EM profiles, EM anomaly intercepts, and OUTPUT PseudoChannel maps have all been employed to carry out the interpretation.

Of a total of 8 discrete conductive trends and areas, 4 have been recommended for high- priority ground follow-up. All targets are listed with ratings in Table 8. A detailed program of ground geophysics is recommended to pinpoint targets before drilling, especially in areas where complex structures appear to be present and conductor axes were not uniquely resolvable.

Any further evaluation of the conductors using the survey products would best be carried out by overlaying the interpretation maps on the OUTPUT PseudoChannel maps and the colour magnetic products, especially the calculated magnetic first vertical derivative. Image analysis of the EM and magnetic data should also form the basis for continued study of the area. As more information becomes available, a detailed program of modelling and interpretation can be carried out to refine the present interpretation.

Respectfully submitted,CGI Controlled Geophysics Inc.

Chris Vaughin Chief Geophysicist

Glenn Boustead, P.Eng. Geophysicist

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* STATEMENT OF QUALIFICATIONS

g I, Glenn Boustead, Geophysicist with CGI Controlled Geophysics Inc. operating at Suite 31, 400 Matheson Blvd. East, Mississauga, Ontario do hereby certify that:

" 1. I am a geophysicist.

l 2. I graduated from the University of Toronto in 1983 with a B.ASc. in Engineering Science (Geophysics option).

3. I have been actively engaged in in geophysical exploration since 1983.

l 4. I am an active member of several professional societies involved with mining geophysics.

5. I was personally involved in the interpretation of the geophysical data in this report.

l 6. I have no interest, direct, or indirect, in the property described nor do I hold securities in Falconbridge Limited.

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' CGI Controlled Geophysics Inc.

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Glenn Boustead, P.Eng. . . m Geophysicist (jAMvl /^.

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Line Spacing

Line Direction

Horizontal Tolerance

Table l - Survey Flying Specifications

200 m nominal

N 25072050 E

Altitude

Vertical Tolerance

Speed

EM Noise Level

Calibration Sequences

Magnetic Noise Level

Diurnal Noise Level

must not exceed 15096 of nominal line spacing for a distance along line of 1.5 km and must never exceed 20096 of line spacing.

120 m nominal

must not exceed 140 m for a distance along line of 1.5 km or more and must never exceed 160 m.

120 knots (220 km/hr, 61 m/s)

must not exceed 20 ppm in the late channels after application of a 1.5 second time constant filter and spherics must not be too frequent to prevent their effect from being removed.

minimum of 2 calibrations for flights under 2 hours duration and minimum of 3 calibrations for flights over 2 hours duration.

must not exceed 1.0 nT over a distance along line of 3 km or more.

must not exceed 10 nT during a 2 minute chord

lm ^ Table 2 - Project Deliverables

l * Flight path on photomosaic base, mylar plus prints

* Electromagnetic Interpretation with EM anomalies and flight path on B photomosaic base, mylar plus prints

* Blackline contours of Total Magnetic Field with EM anomalies and flight path on B photomosaic base, mylar plus prints

* Blackline contours of Calculated Magnetic First Vertical Derivative with EM B anomalies and flight path on photomosaic base, mylar plus prints

* Colour-filled and blackline contours of Total Magnetic Field with EM anomalies B and flight path, laminated paper

* Colour-filled and blackline contours of Calculated Magnetic 1st Vertical B Derivative with EM anomalies and flight path, laminated paper

* Levelled GEOTEM® Channels 2 and 5 as colour plan profiles with flight path, B paper

* OUTPUT PseudoChannel 2 colour-shaded plan profiles with flight path, laminated B paper

* OUTPUT PseudoChannel 5 colour-shaded plan profiles with flight path, laminated B paper

* Multi-parameter stacked profiles of EM, OUTPUT processing results, magnetic, l and ancillary data parameters presented as analogue chart records at

approximately 1:20,000 scale, l copy of l roll

B * Located digital line archive of all final parameters, l copy of l tape

B * RTI-ready digital grid archive of Total Magnetic Field and Calculated 1st Vertical Derivative on IBM compatible diskette, l copy of l disk

" * Data processing and interpretation report including sub-contractor's survey logistics report.

* Survey flight logs, video tapes, chart records, and field mosaics, l copy of each

lN.B. Unless otherwise noted, all map products cover the survey area in one map sheet at a scale

of 1:10,000.

l

1 1111111111111

^ Table 3 - GEOTEM® EM Receiver Window Positions

Window Start (jus)

1 312

2 469

3 625

4 781

5 937

6 1,094

7 1,250

8 1,406

9 1,562

10 1,719

11 1,875

12 2,031

N.B. At base operating frequency

End OLIS) Centre (/is)

468

625

781

937

1,093

1,250

1,406

1,562

1,718

1,875

2,031

2,187

390

547

703

859

1,015

1,172

1,328

1,484

1,640

1,797

1,953

2,109

Width (/is)

156

156

156

156

156

156

156

156

156

156

156

156

of 150 Hz, group delay of approximately 100 us and pulselength of 1,042 fis yields 2,187 /is

11111

of off-time.

Table 4 - Levelled GEOTEM® Channel Histogram Analysis

:hn#

123456789

101112

MinValue

-117-88-50-73-49-28-64-43-63-64-21-27

2SDBelow

-19-17-16-15-14-15-14-13-13-12-12-12

1SDBelow

-9-7-7-7-7-7-6-6-6-6-6-6

PeakAmplitude

100000000000

1SDAbove

1298888877766

2SDAbove

1316639252017171516161413

MaxValue

3,5371,8591,108

64645935023218314314997

111

N.B. All values expressed in ppm. Width refers to the span between the two standard deviations (SD).


Parameter (Chart Label)

Right Number

Line Number

Fiducial

Table 5 - Analogue Chart Record Format

Scale (or Format) Zero Position

Labelled at start and end of each line if available (Default is 1)

Labelled at start and end of each line

Event mark every 10 fids and label every 100 fids (-10 seconds) along bottom of chart.

Primary Field (PRIM)

Altimeter (ALTM)

Fine Magnetic Field (FMAG)*

Coarse Magnetic Field (CMAG)

OUTPUT Fit Index (INDX)

OUTPUT Time Constant (TCON)

GEOTEM® Channel l (EM01) GEOTEM® Channel 2 (EM02) GEOTEM® Channel 3 (EM03) GEOTEM® Channel 4 (EM04)

GEOTEM® Channel 5 (EM05) GEOTEM® Channel 6 (EM06) GEOTEM® Channel 7 (EMO?) GEOTEM® Channel 8 (EM08)

GEOTEM® Channel 9 (EM09) GEOTEM® Channel 10 (EM10) GEOTEM* Channel 11 (EMU) GEOTEM* Channel 12 (EM12)

Power Line Monitor (HYDR)

200,000 ppm per cm

50 feet per cm

50 nT per cm

l,000 nT per cm

l unit per cm

250 jus per cm

400 ppm per cm 400 ppm per cm 400 ppm per cm 400 ppm per cm



100,000 ppm per cm

6.0cm

10.0 cm

60,OOOnTat20.0cm

60,OOOnT at 29.5 cm

7.0cm

10.0 cm

21.5cm 22.0 cm 22.5 cm 23.0 cm

24.0 cm 24.5 cm 25.0 cm 25.5 cm

26.5 cm 27.0 cm 27.5 cm 28.0cm

30.0 cm

N.B. Chart positions are measured from top of chart down.


Table 6 - OUTPUT Processing Summary

OUTPUT PROCESSING CONTROL SCREEN FOR: Rhodes VMS Project

Time Gates

Chan.* 01 02 03 04 05 06 07 OB 09 10 11 12 On/Off ********

Centre 390 547 703 859 1015 1172 1328 1484 1640 1797 1953 2109 Width 156 156 156 156 156 156 156 156 156 156 156 156

Fitted Statistics/Total # Fits

ASCD 1052. 345.7 474.0 192.1 50.28 53.91 43.98 55.42 0.00 0.00 0.00 0.00ACD 15.07 -9.25 -8.97 -5.71 -1.93 .08 1.92 2.03 0.00 0.00 0.00 0.00ACA 162.6 84.51 51.15 33.02 23.09 16.21 12.32 8.71 0.00 0.00 0.00 0.00

ASCD ....... Average Squared Channel Deviation.ACD ........ Average Channel Deviation.ACA ........ Average Channel Amplitude.

TOTAL NUMBER OF TRANSIENT MEASUREMENTS .. 27255TOTAL NUMBER OF FITTED MEASUREMENTS ..... 1929PERCENTAGE OF MEASUREMENTS FITTED ....... 7

PERCENTAGE OF FITTED DATA MEASUREMENTS VS FIT QUALITY FOR TIME CONSTANTSA*******************************************************************************

FIT INDEX > 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 tO

X FITTED 3.58 17.16 22.71 27.58 36.13 50.49 65.84 90.93 97.67 98.76 1.24

TIME CONSTANT -----...----.....--. ....... PERCENTAGE ..............

O - 24 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0025 - 49 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0050 - 74 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0075 - 99 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00100 - 124 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00125 - 149 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00150 - 174 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00175 - 199 0.00 0.00 0.00 0.00 0.00 0.00 2.05 1.48 1.38 1.36 0.00200 - 224 0.00 0.00 0.00 0.00 0.00 1.95 2.91 2.11 1.96 1.94 0.00225 - 249 0.00 0.00 0.00 .19 4.88 4.21 4.49 3.36 3.13 3.10 0.00250 - 274 0.00 0.00 0.00 1.50 2.73 3.49 4.17 3.42 3.18 3.15 0.00275 - 299 0.00 0.00 0.00 .75 1.72 7.29 6.61 5.70 5.31 5.25 0.00300 - 324 1.45 5.44 5.48 5.83 5.16 5.65 5.20 5.07 4.72 4.67 0.00325-349 15.9427.4926.4824.8121.6618.1714.8811.6310.8310.71 0.00350 - 374 23.19 15.41 16.89 17.11 15.64 13.04 10.47 8.49 7.91 7.82 0.00375 - 399 17.39 11.78 11.19 10.71 10.04 8.21 6.85 5.70 5.31 5.25 4.17400 - 499 39.13 34.74 34.70 31.39 27.40 22.18 19.61 16.59 15.50 15.38 29.17500 - 599 2.90 5.14 4.11 5.64 6.46 7.19 7.01 7.35 6.85 6.82 4.17600 - 999 0.00 0.00 0.00 .38 1.15 1.33 3.62 9.18 9.61 9.61 4.171000-f 0.00 0.00 1.14 1.69 3.16 7.2912.1319.9024.3124.9358.33


Table 7 - Line Archive Data Format

ARCHIVE TAPE OF OUTPUT PROCESSED DATA

CGI CONTROLLED GEOPHYSICS INC.

SUITE 31, 400 MATHESON BLVD. EAST MISSISSAUGA, ONTARIO

TEL 416-568-4040 FAX 416-568-4041

12345678910111213

MAY 9, 1991

CLIENT

SURVEY AREA

NTS SHEET

NUMBER OF FILESFILERECORD LENGTH

VARIABLE (units)

JOB | 6039

FALCONBRIDGE LIMITED

RHODES VMS

41-1/14

1DATA FILE188 BYTES

FORMAT

LINE (line*100*attempt) 18FIDUCIAL 18EASTING (UTM m) 18NORTHING (UTM m) 18RAW MAGNETIC FIELDPROCESSED MAG

(nT) 18(nT) 18

ALTIMETER (feet) 1812 GEOTEM CHANS (ppm) 18PRIMARY FIELD (ppm) 18HYDRO MONITOR (ppm) 18INITIAL AMPLITUDE (ppm) F8 . 0TIME CONSTANTFIT INDEX

(us) F8.0F8.0

PROJECT

STARTBYTE

19172533414957153157165173181

ENDBYTE

8162432404856152156164172180188

NB: Data which did not fit the OUTPUT model contain a -99. for the FIT INDEX VALUE and zero for the INITIAL AMPLITUDE and TIME CONSTANT. Perfect fits have a FIT INDEX VALUE of 100.

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Table 8 - Summary of Targets for Follow-up

Name Line Range Priority NotesR2 13901 -14501 ModerateR3 13401 -14101 HighR4 11401 -12201 LowR5 12701 -13001 HighR6 13001 -13101 HighR7 12001 -12501 HighR8 12101 -12501 ModerateR9 11801-11901 Moderate


lCONTROLLED GEOPHYSICS

' l

Survey Area Location Map

Figure l Job 6039

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INPUT Tx CURRENT

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SHUT OFF TIME

TIME GflTE POSITIONS

TRRNSIENT RMPLITUDE

AIRCRAFT POSITION'

11 '1 1 11 1 11 11 11 11 111•K1

EM CHANNEL HISTOGRAM ANALYSIS

1 File Name J6039B.FL.1.NOE Start Record 1 End Record 27E56 Resolution 1 ppm Accept ALL SURVEY LINES

A Channel 1i i i i j i i i | i i i | i i i | i i t

A Channel 2i i t i j i •-••—j "j""~i v""~f | ' i i r j' r i' 'i

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A Channel 5i 1 i i t 1 i t i j i t i | i t i | i i i

A Channel 6i 1 i i i 1 i i i 1 i i i 1 i i t 1 i i i

0 200 400 600 BOO

Amplitude Value (ppm)

N.B. Equal area under all histograms. Blanks signify no occurrences.

1 GEOTEM® Channels 1 through 6CONTROLLED GEOPHYSICS ™stoz™ms

1 Figure 3a Job 6039

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FITTED EXPONENTIAL Aft) - Ao EXP(-tXc)where Ao s Initial AmpL where c a. Time Constant

Measured Data AI

AEM CHANNEL TIME GATES

7CONTROLLED G EOPHYSICS

lOUTPUT Processing Principles

Figure 4 Job 6039

940000-

37500-

35000-

32500-

30000-

27500-

25000-

22500-

2? 20000- Q. Qj 17500-

lil (ft 1 5000-ZO 12500-Q.[y 10000-

GC 7500-

5000-

2500-

0-e

TARGET PARAMETERS\ STRIKE LENGTH 1000. fi

PLUNGE LENGTH 500.0 n DEPTH 0.0 ft DIP 60.0 deg SIGHAXt 20.0 BhDS

SYSTEM PARAMETERSPERIOD 6940 US GEOMETRY: X 93.6 n

l 67.9 o RYING HEIGHT 120.0 A OFFSET 0.0 li COIL- Tx 3 Rx i

i t i t i

A1 ——— A —— ;/\———————————— . — ' ^* ——————— 4.

. —————— - ——————— — ——————— 4.

————— i ————— i ————— i ————— i ————— i ————— t.00 -400 -200 0 200 400 BOO

DISTANCE (m)^T' Thin PLATE Anomaly ObservedCONTROLLED GEOPHYSICS KM*™™*"**

/ Figure 5a Job 6039

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SYSTEX PARAMETERSPERIOD 6340 us GEOMETRY: X 93.6 o

1 67.9 B RYING HEIGHT 120.0 B OFFSET 0.0 m COIL Tx 3 fix i

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————————————— - ———— ——————————— 4-

————— i ————— i ————— i ————— i ————— i ————— t.00 -400 -200 0 200 400 BOO

DISTANCE (m)~T~

7 Thin PLATE Anomaly ObservedCONTROLLED GEOPHYSICS w**"**** 6*'/ Figure 5b Job 6039

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Appendix A - Geoterrex Ltd. Logistics and Processing Report

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LOGISTICS AND PROCESSING REPORT

m of the

AIRBORNE GEOTEM9 ELECTROMAGNETIC AND MAGNETIC SURVEY

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SUDBURY, ONTARIO

for

CGI CONTROLLED GEOPHYSICS INC.

GEOTERREX Lw,PROJECT No. 619

FEBRUARY 1991

lid.

TABLE OF CONTENTS

1. INTRODUCTION . .. . .. .. ..... . . . . . . .. .. . ..... ....... .. .. . . . 7

//. SURVEY OPERATIONS . .. . .... ... .. . . . .. . ...... ... , ., .. .. . ... 21. Location of the Survey Areas . .................,.,...... 22. Flight Line Directions . ..........................,...... 23. Flight Altitude . ....... ...... ...................... ... 24. Navigation . ..... -........ ,.......................... 25. Aircraft 8c Geophysical On-board Equipment .............., 26. Ground Computer Installation . ......................... 67. Diurnal Variation Monitor Equipment . .................... 65. Pre-Su/vey Tesfs .........,....,....,.......,......,... 7

o) F/gure of Mer/f ,,..,,..,,.,....,,..,,............ 7b) Lag Tesfc (Magnetic 5c Electromagnetic) , ..,.,,....,. 8c; A/f/fude Calibration . ............................. 8d) Magnetic Cloverleaf Test . ........................ 8e; GEOTE/W9 EM Sysfem ...........,................. 9

9. Survey Specifications . .......................,....... 70a) Navigation . ..................,................ 70b) A/f/fude ...................................... 70c) EM No/se ILeve/ ................................ 70d) Magnetic Noise Level . .......................... 7 ?e) Diurnal Conditions . ...........'.,..,,.,.,........ 7 J

70. F/e/d Operations . ..........,........................ 7 7

///. DATA PROCESSING . .. . .. .. . .... . .. ....,..... .. ... .. , 127, FWgfif Pafh Recove/y ....................,............ 722. Magnetic Data Processing , .,.............,........... 72

a) Ed/f/ng of A/r Dafa ....,..........,,..,........., 72b) Ed/f/ng of Diurnal Records . ....................... 73c) Smoothing Data . .......,....,................. 73d) Subtraction of the Diurnal Field . .......,........... 73e) Interpolation of the Data . .................,.,... 74O Correction for Lag . ..........'..,................ 74g) Tofa/ Intensity Contour Map . .........,........... 74

3. GEOTEM* Electromagnetic Data , ...............,..,... 754. Products , .............................,........... 15

a) Base Map ,................................... 75b) fl/ghf Pafh Map ... -......,.......,.............. 75c) Contour Map . ..,..,.......................... 75d) Archive Tape .............,.................... 76

neotera9 ltd.

l*L INTRODUCTION

During the period 12 November, 1990 to 12 January, 1991 a combined airborne magnetic and GEOTEM® electromagnetic survey was flown for CGI CONTROLLED GEOPHYSICS INC. by GEOTERREX Limited. In all, 260 kilometres of survey lines were flown over a survey block near Sudbury, Ontario (see Figure 1).

The survey area was outlined to generally map the Archean volcanics and metasediments present over this edge of the Canadian Shield. These rocks are associated with numerous mineralization occurrences. The magnetic and electromagnetic responses mapped over these volcanics and surrounding rocks yield important structural, textural and compositional information which will be useful in most exploration applications.

The data were compiled and processed in Ottawa by GEOTERREX Limited and arc presented as a flight path map, a photomosaic base map, a total magnetic intensity contour map, and digital archive tapes.

l l l l l l l l l l l l l l l l ll geotBrTEK

II. SURVEY OPERATIONS

l 1. Location of the Survey Area

I The survey block is located immediately north of Sudbury It is known as the Rhodes VMS project.

l 2. Flight Line Directions

l The area was covered with flight lines oriented at N24OE, at a nominal spacing of 200 m. A total of 260 km of data were collected.

™ 3. Flight Altitude

" The survey was flown at a height of 120 m above ground whenever possible, with

• regard to topographic relief and commensurate with the safety of the aircraft and bird. This flying altitude maintains the EM sensor (located in a towed bird at the end of a 135-m cable) at approximately 64 m above the ground.

4. Navigation

The navigation was primarily visual, using airphoto mosaics at a scale of 1:20,000, l prepared by GEOTERREX Limited. The navigation was aided by the GPS satellite

and Doppler navigation systems.

" 5. Aircraft Si Geophysical On-board Equipment

l The survey aircraft used was a CASA C212-200, twin turbo-prop STOL aircraft, maintaining a survey speed of 120 knots (220 km/h, 61 m/s).

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neoterrexSi ltd.


FIGURE 1. LOCATION MAP

The following equipment was on board the aircraft:

GEOTEM* Electromagnetic System: Comprising a transmitter and loop, a digital receiver, and a sensor mounted in a towed bird. A description of the gate settings used for this survey may be seen in Table 1.

MADACS Digital Acquisition System: Combining an Interdata 6/16 16-bit microprocessor and a Digi-Data 1640, 9-track, 800 bpi tape drive. The following information was recorded digitally:

20 GEOTEM* EM channels

• Magnetic total field Barometric altitude

• Radar altitude Time (fiducials)

- Doppler velocity along track l - Doppler velocity across track

Doppler heading l - Primary EM field

60 hertz powerline monitor l - Noise monitor

-3 reference monitors

1 7 OPS fields: lat., long., elevation, acquired time, universal time, satellite time, standard deviation.

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neoteiTEKSlud.

TABLE l GEOTEM* Gate Description

Gate

1

2

3

4

5

6

7

8

9

10

11

12

13-20

Center

393 jisec

549

705

862

1018

1174

1330

1487

1643

1799

1955

2112

Width

156 jisec

156

156

156

156

156

156

156

156

156

156

156

Used for diagnostic purposes.

Note; All times shown are in microseconds after termination of the transmitter current.

Magnetometer: Scintrex cesium vapour, single-cell, split-beam magnetometer, 0.1 nT sensitivity, l s sample rate, mounted in a stinger on the tail of the aircraft.

Altimeters; - Radar altimeter: King KRA405- Barometric altimeter: Rosemount AVH8

lneoterrex29 ltd.

5Tracking Camera; Panasonic V.H.S. video with 4.2 mm lens mounted

vertically, recording in NTSC mode, with fiducial marks every second.

Analog Recorder; RMS-GR-33A-1 heat-sensitive graphic recorder, displaying the following information on a 32-cm wide chart, running at a speed of 9 cm/min;

12 GEOTEM* EM channels (low-pass filtered with a l .5-second time constant in real time) at a vertical scale of 200 ppm/cm for the first 10 cm, 400 ppm for the next 10 cm, and 800 ppm to the top of thechart.

Channels 3 and 12 are also plotted, without the filter, at vertical scales of 400 ppm/cm and 200 ppm/cm respectively.

The magnetic total field at vertical scales of 50 and 500 nT/cm.

The radar altitude at a vertical scale of 50 feet/cm.

The barometric altitude at a vertical scale of 24 millibars/cni increasing downward.

The primary EM field monitor at a vertical scale of 240,000 ppm/cm.

60 Hz powerline monitor at a vertical scale of 150,000 microvolts/cm.

Fourth difference of the total magnetic field at a vertical scale of 10 nT/cm.

Time (fiducial) markers, ticked every 2 seconds and labelled every 20 seconds.

quote™SI ltd.

- Absolute values of the magnetic total field and both altimeters are printed every 40 seconds.

l 6. Ground Computer Installation

l - Compaq HI microcomputer with a 40 Mb hard disk and Dell 310 micro computer with a 110 Mb hard disc using GMAPS software developed by

H GEOTERREX Ltd.

m - Digi-Data, 9-track 1600-bpi tape drive, model 1649.

— - Zeta plotter, model Zeta 8A.

- Epson LX-800 printer.

Gentian table top digitizer.

7. Diurnal Variation Monitor Equipment

A Scintrex single-cell, split-beam, cesium vapour magnetometer measuring m the total magnetic field at 0.1 nT sensitivity with a 0.5 second sample rate.

I A Madacs digital acquisition system, based on an Interdata 6/16 microcomputer; recording time and the output from the magnetometer.

l -A Digi-Data tape recorder.

l - A Seiko heat sensitive analogue recorder, displaying the total magnetic fieldat 2.9 nT/cm on 7-cm chart paper, run at 1.45 min/cm.

The base station was set up in Sudbury.

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8. Pre-Survey Tests

a) Figure of Merit

The aircraft is put through a series of pitches (± 50) yaws, (± 50) and rolls (± l O0), to examine the noise induced in the magnetometer resulting from aircraft manoeuvres (due to the eddy currents generated by the aircraft itself plus the changes in orientation of ths sensor with regard to the earth's field). This test shows how well the instrument is compensated.

The results of the Figure of Merit obtained in June of 1990 are presented in Table 2.

TABLE 2 FIGURE OF MERIT RESULTS (with GEOTEM system on)

Direction

East

East

East

North

North

North

West

West

West

South

South

South

Manoeuvre

Pitches

Rolls

Yaws

Pitches

Rolls

Yaws

Pitches

Rolls

Yaws

Pitches

Rolls

Yaws

Noise (nT)

0.30

0.15

0.20

0.40

0.15

0.15

0.50

0.15

0.15

0.40

0.15

0.15

Total Figure Of Merit ** 2.85 nT

Average noise per manoeuvre - 0.24 nT

p geoteraS3 ltd.

b) Lag Tests (Magnetic A Electromagnetic)

The camera on board the aircraft records its position, A, relative to the ground at time to. In fact, the sensor will arrive over A at time tj > to. Furthermore, because of electronic delays, the reading performed at time tj will be recorded on the magnetic tape at time tj > t,. The difference tj - to represents the "lag" between the actual position of the aircraft and the position of the corresponding reading on the magnetic tape.

l The test is performed by flying the aircraft at survey altitude in opposite directions over— a well defined magnetic and electromagnetic anomaly. The difference in the position of l the anomalies, recorded in both directions, is equal to twice the lag. The following lag

values were thus determined in the field.

Magnetometer - 0.67 s (equal to 4 EM sample intervals)

GEOTEM EM s 4.1 s (equal to 25 EM samples)

l These lag values were taken into account at the processing stage by shifting the digital U values correspondingly back in time.

m c) Altitude Calibration

— The calibration of the radar altimeter is factory-set so as to display the aircraft's height l above ground in feet. No further calibration is required. The linearity of the instrument

output onto the analog chart was confirmed in September, 1989, by flying at heights of l 300, 400, 500, 600 and 750 m.

l d) Magnetic Cloverleaf Test

l A cloverleaf test was flown in June 1990 to verify the heading differences of the magnetometer. The test consisted of flying in the four cardinal directions over a common

l point on the ground and examining the differences in the magnetic readings (normalized to a common datum). Table 3 gives the results of the test.

l l l

neoterrex21 ltd.


TABLE 3 CLOVERLEAF RESULTS JUNE 1990

Direction

West

South

East

North

Radar Altimeter

457'

366'

405'

395'

Diurnal

60237.49 nT

60239.39 nT

60240.08 nT

60239.45 nT

Air mag.

60470.85 nT

60474.10 nT

60471. 75 nT

60470.60 nT

Air mag. corrected for diurnal and altitude (@lnTAOO')

233.36 nT

234.71 nT

231.67 nT

231.15 nT

Difference North-South ^ 3 .56 nT

Difference East- West ^ 1 .69 nT

Difference Average North South - Average East West s 0.67 nT

e) GEOTEM® EM System

The GEOTEM* EM system benefits from a completely digital receiver which monitorscontinuously (i.e. 6 times a second) the current in the transmitter and the amplitude of theprimary field, as seen at the bird-receiver. This feature permits an automatic internalcalibration to parts per million and therefore, pre-survey calibrations are not required (seeAppendix A). However, a compensation is required because of the residual signal afterthe transmitter pulse. This residual results from a number of sources which includetransmitter imperfection, aircraft response and receiver bandwidth limitations.Compensation is carried out at the beginning and end of each flight and after 2 hours intoany flight exceeding 2 hours. The EM signal is measured at flying heights well above thepoint where the ground response can be detected. The observed response can then beattributed to deviations of the system from ideal. This allows measurement of the peaktransmitter amplitude, A0p, and the residual signal at off-time observation window n, A0n.Window n is assumed to be located at time t,, after the transmitter turn off time. A0p andA0n are averaged over l to 100 seconds depending on the particular survey design andambient noise conditions. The resulting values of A0P and A0n are saved in the digital

neoterrex3 ltd.

l• (^receiver for compensation of survey data. The compensation process is applied as follows.

The instantaneous peak primary received field, A'p, is measured for data stack, i. The I signal in window or gate n is measured for each data stack i to be A!n. The compensated

value of A'n denoted as W1, is expressed as follows:

ll *-4-C;JK

ll 9. Survey Specifications

m Lines were reflown if any of the following limits were exceeded.

m a) Navigation

— Flight line spacing cannot exceed the nominal line spacing (200 m) by more than 5096 for l more than 1.5 km.

l b) Altitude

l Altitude must not exceed ± 20 m of the prescribed 120 m terrain clearance for more than 1.5 km, and never exceed 160 m, unless required for safety.

* c) EM Noise Level

l l

Noise level must not exceed ± 20 ppm, as monitored on.the late channels of the analog, with a 1.5-second time constant over a distance of 3 km or more; and atmospheric disturbances must not become so frequent that their distortion of the signal cannot be

. accurately removed.

l l l

d) Magnetic Noise Level

Noise level must not exceed ± 0.5 nT over a distance exceeding 3 km. This is monitored on the analog fourth difference trace where 0.5 nT noise will be expanded to 5.0 nT.

e) Diurnal Conditions

Magnetic storms were defined as exceeding 10 nT departures over a 2-minute chord, during which time survey flying would be halted.

B 10. Field Operations

l The following GEOTERREX personnel acted as the primary field operation crew:

l R. Smith Project Manager, DatamanK. Ireland Dataman

l S. Hay PilotA. Capyk Co-Pilot

l J. Trepanier EngineerA. Proulx Electronics Technician

l

l l l

In addition, the following GEOTERREX personnel acted as supplementary or replacement field operation crew:

B. Byerley Geophysicist C. Ivimey Engineer

l l— M. Nash Engineer l F. Corriveau Electronics Technician

M. Carson Senior Management

The crew was based in Sudbury, with production from 12 November, 1990 to 12 Januaiy, l 1 991 '

neoterrexa ltd.

l l l l l l l l l l l l l l l l

i

l HI. DATA PROCESSING

1. Flight Path Recovery

The flight path was recovered in the field by identifying points on the video tracking film and on the photomosaics, at a scale of 1:20,000. These points were then digitized on a flat-bed digitizer table, directly from the photomosaics.

After checking for errors by calculating the average speed of the aircraft between picked points, the flight path was automatically plotted at a scale of 1:20,000. The flight path coordinates were recovered in UTM metres, using the Clarke 1866 Spheroid projection with a central meridian of 81 0W, a false easting of 500,000, a false northing of O and a scale factor of 0.9996.

Both the Doppler and OPS flight paths were also recovered in the field and merged with the visual flight path by updating to the picked points, thus gaining more accurate positioning between the picked points, as well as an additional quality check on the accuracy of the picked points.

2. Magnetic Data Processing

a) Editing of Air Data

After reformatting the field tapes, the flights were broken into individual lines and the total magnetic intensity, radar altimeter and time fiducials were verified for continuity and validity by generating a statistical listing of maximum, minimum, mean, standard deviation, and variance. This will locate any major busts or gaps in the data.

Following this, obvious errors in the digital records of the raw total intensity were detected by creating an error listing using the fourth difference of the raw total intensity values. Such defects as spikes or missing values were automatically corrected by the program or simply flagged and corrected manually when outside the limits of the program.

PPBR

13 b) Editing of Diurnal Records

The ground station analogs were initially examined to identify cultural disturbances such J as anomalies created by passing vehicles. Once identified, these disturbances were

removed from the digital data by fitting a curve to the data based on the best polynomial l fit (via the use of a graphics terminal).

l The digital data were then verified and edited in the same manner as the airborne data. ™ That is, the data were first examined for busts or gaps using the statistical analysis. It was

then edited using the same fourth difference routine as used on the air data, with any badvalues corrected down to the same thresholds.l

l c) Smoothing Data

l The digital values from both the ground station and airborne magnetometer were smoothed by applying a triangular convolution, with an amplitude threshold of 0.75 nT.

The digital radar altimeter readings were also smoothed by the same triangular l convolution, with an amplitude threshold of 10 feet.

l The triangular filters above were set to smooth noise events of less than 4 samples in* width.

" d) Subtraction of the Diurnal Field

l The degree to which the diurnal signal was being seen on the airborne records was— carefully examined. The short period diurnal events were not seen in the air records,l Thus, only the long period diurnal events were removed from the airborne magnetics; tliism improves the levelling of the data prior to contouring. A triangular filter removed alll diurnal events shorter than approximately 50 seconds.

I To maintain the recorded airborne magnetic values in their proper regional range, the mean diurnal value of 58,120 nT was added back to the air data after subtraction.

i l l


14 re) Interpolation of the Data

The magnetic data, which were originally recorded at the rate of l sample per second, were then expanded to 6 samples per second by interpolating a fourth-order polynomial curve between sample points. This was done to allow merging the magnetic data with the electromagnetic data, which was originally recorded at 6 samples per second.

f) Correction for Lag

The magnetic digital values were shifted back in time by 0.67 s (corresponding to 4 EM samples), to make them coincide with their true positions over the ground.

g) Total Intensity Contour Map

The magnetic data used as input to the contours were the total intensity after editing of bad values and noise filtering.

In order to contour the magnetometer data, the values from the lines and tie-lines were levelled together. This was done automatically by comparing the values of the total field at the intersection of each line and tie-line. The differences were analyzed and a compensation was calculated at each intersection in order to provide a pattern of smoothly varying adjustments along each line and tie-line. Erratic differences, implying an error in the intersection location, were carefully checked and corrected.

The values were then sorted and gridded along an 25 m grid, which at the map scale o: 1:10,000 is equal to 2.5 mm. A triangular convolution was then applied to the gridded values to smooth the contours. The gridded values were then automatically contoured using the following intervals:

Rhodes VMS: 5nT

neoterrex3 ltd.

l

GEOTEM* Electromagnetic Data

After reformatting the field tapes, the data were verified and edited to produce files representing continuous EM coverage of the area flown. Statistics were generated (minima, maxima, mean, standard deviation and variance) on a line-by-line basis for each channel of the raw data recorded in order to verify the data content and check for any irregularities. To facilitate interpretation, a lag of 4.1 seconds (25 digital samples) \vc.s

• then applied to the data in order to line-up the EM anomaly peaks from one line to the next.

4. Products

a) Base Map

J A photomosaic base was produced:

b) Flight Path Map

A flight path map was produced, superimposed on the matching photomosaic basemap

lc) Contour Map

l A total intensity magnetic contour map was produced on a clear base, at the following scale and contour interval: 1:20,000 with a 10 nT interval..

l l l l l

neoterrex9 hd.

lm 03. GEOTEM® Electromagnetic Data

B After reformatting the field tapes, the data were verified and edited to produce files l representing continuous EM coverage of the area flown. Statistics were generated

(minima, maxima, mean, standard deviation and variance) on a line-by-line basis for each l channel of the raw data recorded in order to verify the data content and check for any

irregularities. To facilitate interpretation, a lag of 4.1 seconds (25 digital samples) was l then applied to the data in order to line-up the EM anomaly peaks from one line to the

next.

4. Products

™ a) Base Map

l A photomosaic base was produced:

lb) Flight Path Map

A flight path map was produced, superimposed on the matching photomosaic basemap

l

c) Contour Map

™ A total intensity magnetic contour map was produced on a clear base, at the following

l l l l l l

scale and contour interval: 1:10,000 with a 5 nT interval.

16 Archive Tape

The archive includes magnetic, altimeter, position, and electromagnetic data from profile, plus the gridded magnetic data. A full format description is included with the tapes and in Appendix A.

RESPECTFULLY SUBMITTED

lRon Lyall, Processor

l

Cord Roberts, Processor

l l

Brian Schacht, Geophysicist

l l l l l l l

geoterrex

Appendix B - Flight Logs

l l l geoterrex limited

OTTAWAGEOTEM - SPECTRO - DIGITAL

l

l

l

JOB NUMBER t .

OPERATIONS BASE' S P

PILOT t . . . . 3ft. . ,.

DATE FLIGHT NUMBER

AREA NAME t

CO-PILOT i . . . . S .H . . . . . . . . . . . OPERATOR

TAPE NUMBER' (Digital)

, FILM NUMBER ' (T)

FID START ......................... FID END,l FltEMARK CHECK(V)

1 BEGIN END 1

-ANALOG SC ALES -

JLOW TIME CONSTANT' ....... ppm/cm

FAST TIME CONSTANT : ....... ppm/rm

TOTAL FIELD :...................... mv/em

f MAO FINE : ............................... B X em

COARSE!............................. B X cm

IBIRD S IGNAL: . ......^.O....?..?...... volts

RADAR ALT i.......

BARO ALT :.......

SPEaRO TOTAL :

K 40: ..

UR :......

TH:......

. m/em . m/em

.Cts/em

.Cts/cm

..Cts/em

..Cts/em

FULI SCALE'

......... em

em

PRE AMP SIGNAL

-POST FLIGHT COMMENTS -

TOTAL FLIGHT TIME t

MILES/KMS FLOWN

ON LINE'

M1LES/KMS ACCEPTED

FLIGHT COMMENTS

WEATHER ' . .0..(J.:\).CA.C.A.S.(~^.-..-irOA

ATMOSPHERICS t . .^frJsfojvW.W..........

NAVIGATION '

WIND * .... .. ,mph

lt

LINE No PART

l l

DIR. FID START

FID END

^.COMMENTS MILES 1 KMS

M

lot u-0 lu Coo .1 R. tO ' fi

M5M in ft*

l HiM

rr/5//9 *

i i

Ut! " M s"/ /

S "C C-

A/

1 Li L,

5*5745

NXLLL

(We

\ ftW/l). x


geoterrex limitedOTTAWA

GEOTEM - SPECTRO - DIGITAL

JOB NUMBER t . . ^ /fi. . . . , . . . DATE : . / . jtf.l.1'te . . . . . . FLIGHT NUMBER t . 3 4f. . . . .

OPERATIONS BASE' 5*J ^. . . AREA NAME '

PILOT i. . . . . 2 . ft . . . . . . . . . . . . CO-PILOT t . . . . S? .EV . . . . . . . . . OPERATOR i

TAPE NUMBER' . Jlf.r./................. F ID START ......................... FID END(Digital)

F1LEMARK CHrCK(V)

FILM NUMBER ' (f)

BEGIN END

-ANALOG SCALES-

tFOTEMSLOW TIME CONSTANT' ......, ppm/tmFAST TIME CONSTANT : ....... ppm/xmTOTAL FIELD :...................... mv/cm

MAO FINE : ............................... B X cmCOARSE: ,........................... B X cm

BIRD SIGNAL: .............................volts

RADAR ALTs............... m/cmBARO ALT :.............. m/emSPEQRO TOTAL : .........Cts/em

K40' ...........Cts/em

TH :........... ....Cts/em

FULL SCALE'

.cm , cm .cm , cm

PRE AMP SIGNAL :

-POST FLIGHT COMMENTS-

TOTAL FLIGHT TIME ' ...'Z*X..........:........... ON LINE' ................O' 0!

MILES/KMS FLOWN i .......................,. ........ MILES l KMS ACCEPTED '

FLIGHT COMMENTS

WEATHER

ATMOSF'HERICSt.

NAVIGATION ' ..............,..................................................

WIND J ...^^...SC/wy......................................... ....mph

l l l l l l l

LINE No PART DIR.FID

STARTFID END

FLT** L. COMMENTS - , MILES] KMS

Xx

S•^ — ) 010)

N Co*-/ ft,

112 S" 97*121 XT/ 5^^

I ILL

lllllllllll

H? -- AJ

N

s.

s 7*8 Ut

//Z

(oS Si 57-TO /C 5 Z. 71

/J n

10182* t'otrfl

en kX.

6o),6o A

geoterrex limitedOTTAWA

GEOTEM - SPECTRO - DIGITALll JOB ^MBER i . . . . ft ! 3. . . . . . DATE :. . A ?. ^.W ftAVs J .1*1 P. . . . FLIGHT NUMBER : 3. ?.

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

l

JOB

OPERATIONS BASE' .3 V*.V SV&Y- - - AREA NAME i . . . . . . . . . . . . . . . . .

PILOT i . . . . . r*.-.Vi . . . . . . . . . . . . . CO-PILOT : . . . . . .?.r.H . . . . . . . . OPERATOR ' . f?, .C j

TAPE NUMBER' (Digital)

FILM NUMBER i

FID START ......................... FID END,l FILEMARK CHECK(y)

I BEGIN END j

-ANALOG SC ALES -

GEOTEMSLOW TIME CONSTANT' ....... ppm/cmFAJVr TIME CONSTANT : ....... ppm/imTOTAL FIELD :...................... mv/em

MAG FINE : .......................,....... a/tmCOARSE: ............................. v / cm

BIRD SIGNAL: ....^TlZ....^........ volts

RADAR AIT i............... m /em

BARO AIT :.............. m/cm

SPECTRO TOTAL : .........Cts/emK40! ...........Cts/em

TH :........... ....Cts/em

FUU SCALE'

,........ em........ cm,........cm

PRE AMP SIGNAL :

-POST FLIGHT COMMENTS-

TOTAL FLIGHT TIME ' ...//..^..././f............. ON LINE*

MILES f KMS FLOWN MILES/KMS ACCEPTED

FLIGHT COMMENTS

WEATHER i ..C. tfr....~.Z... .-.. -.1 ).f:.

ATMOSPHERICS!

NAVIGATION * ...................................... ,..........................

WIND t . ...^.Ai.fX................................................. ....mph

Ci.7lil

l l

xO O 11 \1

Oh-'/' V03,90*7

It. i

l l

x0

9 Z

r*JJJJ f*; c*''

rt

N

Nut

Q^ V

5 r

l l l hN 3NI1 g

x00 1.) C009,

^ r/*o W l i

SW* /S31IW

QN3auau

IdVd PN 3NI1

l

NE No PART DIR.FID

STARTFID END

FLT**22: COMMENTSMILES/

KMS

M

4*580

N

K

Appendix C - Anomaly Listing


UTM Location Total GEOTEM Amplitude Initial Time Fitst North Fiduc. # Alt Mag Ch 2 Ch 5 Ch 8 Ch11 Ampl. Const IndexI'metres) (ft) (nT) (ppm) (ppm) (MS)

Notes

LINE 10201 LINE 10301 LINE 10401 LINE 10501 LINE 10601 LINE 10701LINE 10801

468439 5198453LINE 10901LINE 11001

468945 5198375469119 5198765LINE 11101LINE 11201

469293 5198089LINE 11301LINE 11401LINE 11501

469412 5196739LINE 11601LINE 11701

469402 5196055LINE 11801LINE 11901

469783 5195983469948 5196335470133 5196729LINE 12001

470100 5196201LINE 12101

470303 5195897470395 5196119470709 5196865LINE 12201

470477 5195973470855 5196845LINE 12301

470561 5195521470642 5195697471001 5196517LINE 12401

470778 5195557LINE 12501

471831 5197467470838 5195387LINE 12601LINE 12701LINE 12801

470741 5193757471066 5194413471278 5194885LINE 12901

471304 5194347LINE 13001

590432

585755585833

581275

571982

565041

557719557788557870

555536

553258553302553446

549195549050

546760546794546954

544850

324295324740

562884563026563127

561218

A

BC

A

A

A

ABC

A

ABC

AB

ABC

A

A8

ABC

A

402

422402

418

388

374

407385404

399

396397401

397465

424426431

456

525432

415417444

450

58139

5814158166

58097

58132

58601

581245798957978

58037

581035806858097

5808558114

581735812158095

58151

5821258186

581265835258129

58567

-1

107

14

17

4

5611

67

1144523

48518

398276 2

54

-6

17

-27

64100

503

0

-2

6

8

9

6

116

11

8

1879

1300

108810

12

-5-3

-9

639

182

8

0-1

6

4

-6

680

9

1

4 6

5117

42319

6

-2-9

-2

06

72

1

3-1

1

0

1

-1-3-4

1

7

04

459

623

-4

21

-9 7

6

38

0

00

0

0

0

28400

442

164730195

27930

21221498

0

242

00

0337506

2127

0

00

0

0

0

35800

304

213296443

3360

350347

0

388

00

0361385

411

99

-99-99

-99

-99

-99

30-99-99

44

473424

89 99

9090-99

44

-99 99

-99

4072

88


UTM Location Total GEOTEH Amplitude Initial Time Fit.East North Fiduc. # A lt Hag Ch 2 Ch 5 Ch 8 Ch11 Ampl. Const Index

(metres) (ft) (nT) (ppn) (ppm) (MS)Notes

471389 5194077471518 5194371471679 5194709LINE 13101

471821 5194517471657 5194155471493 5193797LINE 13201LINE 13301LINE 13401LINE 13501

472409 5193995LINE 13601

472567 5193797LINE 13701

472778 5193753LINE 13801

472860 5193459473005 5193779LINE 13901

473589 5194571473281 5193847472951 5193149LINE 14001

473197 5193267473386 5193723473474 5193927473776 5194523LINE 14101

473646 5193803LINE 14201LINE 14301LINE 14401LINE 14501

475746 5196371LINE 50101LINE 50201

475800 5196433

558440558500558570

555251555318555386

546193

543489

541756

538939539003

537040537166537304

534462534555534600534723

532590

522781

521037

ABC

BCD

A

A

A

AB

BCD

ABCD

B

A

B

441455451

459412429

431

463

457

418452

473425441

434445441428

442

455

419

581175813558009

580575806258028

58494

58248

58263

5810058186

580765813358066

58037580655810958103

58082

58119

58092

6010212

3141

-8

31

116

413

9247

-1

18727

45918-6

6

451

1048

20238

118-1

-10

0

40

130

718

1

270

006 3

0

116

287

26

-4

522

-10

-13

13

46

6

8

413

-14

2-14

20

-1

52

159

117 2

23-9

5

-6

1

27

6

4

46-5

-14-3-5-1

-11

22

72

293637

0

108100

0

598

1956

1985265

01282

0

02465

00

0

2448

4802

414318

0

46500

0

377

380

182372

0305

0

0147

00

0

342

381

5368-99

91-99-99

99

76

90

3642

99

79 99

99

34-99-99

99

89

87

9170.

Report of Work . .puNwieia a.MISS RHODES

(Geophysical Geological anc Geocnemicai Surveys) \i~'.'':Ti--:Vsfct'oY"r!''n

900. i" uup'i~a r,ij snouio Df Sj a: Oeveiopme-i: anc Ls-cs

-. -' ^.,'.c*'S' Mining Division ":'.'.'S n| C. o r Area

Geophysical (Airborne Mag-Electromagnetic) .Sudbury .RhodesJTwpP'ospecto' s Lee- c c 've-

V. .21647.hQrit- No

Falconbrijdge Ltd. .Xf- *

P.GvBpx.40, Falconbridge, Ontario. POM ISO ...... ...... , ..,......... ...{7.053. A9J.^2761...

Gepterrex Limited , 2060 Walkley Rd.^.Ottawaj pntario KIG 3P5-:r-. ' -,, ": ' -'--,-- " ••.• f ;i ^-: L4Z 1N3 Date of Survey (from S to)

Glenn Boustead. 400 Matheson Blvd. E., Suite 31, Mississauga, Ont. :., 't-. -- : .a.-""s Traverse-d 'i-^s'

T: "'DVISJDHS

S .107^03.0 .tQ.. j. . S J165688 to 1076033 inclj .. .1165797 incjj

i

64.5 mi

Aprilecorded Ho+tH;

1094203 to ;

1094206 ineli

.1094284 to. i

1094287 inclj

.10943*3: . .l

1117547. to .t

1117549 incli

1117651

1117652

1117654

RECEIVED

SEP 2 4 1991!

MINING LANDS 6.0.

90 i

129

James R. Bartlett 4 850 Morrie Court, Hanmer, Ontario POM 1YOCertified By (SiQnalurei

969-5479

c- Office Use Only

Dale RecoroecA __^f./.i-S Ktty

fxECETVED

tf^!

' Date Approved as Recorded Prov^jarWManape' Mir.irp L.T

#tcv^ '^^^:^-^^:^••^.••^.•'•'/t---':^y.----^---'''^^-\^^ **^ • 'lestf^--. -•\ -. J " 'it \ ••'V*os-fj \*^--\ ' ^^hAÂ-\

,-.^\^^^ '"- o,- :^rr ^^?

A-^' '~*)// (-

f.^*V ijrifis?© 1 !^'-4---^. ffi a,y \

c^;i/ i••j vT"

^CU-/' ^

-•o./r

^'^•^ K -^^^-^^^^^f^^mm^:INDEX TO LAND DISPOSITION

PLAN

.^-4096^TOWNSHIP

RHODES..

M.N.fl. ADMINISTRATIVE DISTRICT

SUDBURY : ' j:MINING DIVISION v' v

SUDBURY .LAND TITLES/REGISTRY DIVISION

SUDBURY :'*-x

f " Y

Scale 1:20 000

1000E

1000 2060 D U*trM

1000 1000 2000 3000 4000 5000 6000 7000 MOO 9000 10 00*

Contour Interval 10 Metre*

AREAS WITHDRAWN FROM DISPOSITIONMRO- M ining Rights OnlySRO - Surface Rights Only v - -M -e S - Mini -g and Surface Rights

SYMBOLS BMC option Ontarlto. DM*

BoundaryTownship, Meridian, Baseline.

Road allowance; surveyed... shoreline...

Lot/Concession; surveyed. .........\.,unsurveyed

Parcel; surveyed ........ r...... -,. -t.unsurveyed

ftlght-of-way; road ....................railway utility.

Reservation

Cliff, Pit, Pile...-.:.................-....

Contour ....................... ; ........Interpolated......................,.'..Approximate Depression.

Control point (horizontal)

Flooded iand

Mine head frame .. .T.-, rr.......... ."T."?..

Pipeline (above ground)

Railway; single irack................,.....double track.......... -... '......abandoned

Road; highway, county, township access trail, bush

Shoreline (original).:.....................

Transmission line.,......................

Wooded area

.f

......a NOTES

Flooding rights to e'cvalion III

Lake ( L.O. 9839) - Hit "921-4

DISPOSITION OF CROWN LANDSPatent

Surface*MiningRights . ..... . ^. .... ...................Surface Rights Only, v...................:......... f.....Mining Rights Only...-........................~.......

Lease .Surface 4 Mining Rights ...... -................. - - -Surface Rights Only... .\:........ *TTf.............Mining Rights Only...............'. .T..,.............

Licence of Occupation ..'.......'. -......;.............

Order-in-Council.. .^. *......... k.......................

Cancelled ......................,................. . r '. .

Reservation... .|... -.. '.'."\.........

Sand 4 Gravel.....,.... .......... -...........:... -..

THE INFORMATION THAT APPEARS ON THtS MAP HAS BEEN COMPILED FROM VARIOUS SOURCES, AND ACCURACY IS NOT GUARANTEED THOSE WISHING TO STAKE MIN ING CLAIMS SHOULD CON SULT WITH THE MINING RECORDER MINrSTRY OF NORTHERN DEVELOP MENT AND MINES, FOR AD DITIONAL INFORMATION ON THE STATUS OF THE LANDS SHOWN HEREON.

TOWNSHIP SUBJECT" ;,H-fl.B

FORESTRY OPERATIONS ''..V .OC

DATE OF ISSUE

.SUDBURY MINIRG RECORDER'S OFRCt

l OWE OF ISSUE

SUD8UW " RECORDER'S OFFICE

.•-/J

Map base and land disposition drafting by Surveys and MappingBranch, Ministry of Natural Resources. . ', -A-*--"

The disposition of land, location ol lot fabric and parcel boundaries on this--dex was compiled kx administrative purposes ooiy. . '

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RPT ON A GEOTEM EM & MAG SUR RHODES VMS …...Rhodes VMS Project located in Rhodes Township approximately 60 km northwest of Sudbury, Ontario. The objectives of the survey were to