Rouyn-Noranda, Quebec Gerard Lambert, P.Eng
April 10, 1998 Consulting Geophysicist
144, rue George, C.P. 2355, Rouyn-Noranda (Quebec) Canada J9X 5A9
Tel:(819) 762-3182 Fax: (819) 762-5364

Introduction

In late March 1998, ground geophysical investigations, consisting namely of Induced Polarization (I.P.) surveys, were carried out at the Sudbury Airport project, for Millstream Mines Ltd.

The purpose of these surveys was to provide appropriate electrical property information about the underlying mafic lithologies and to map with a better accuracy the distribution of potentially nickeliferous disseminated and stringer sulfides in the bedrock. Considering the occurrence of significant Ni-Cu mineralization on and around the property, the relative paucity of bedrock exposure and the lack of adequate I.P. coverage, the present I.P. surveys were meant to complement the geophysical understanding of the property.

This report describes the work done, discusses the results obtained as well as the interpretation of the data. Recommendations for any future work are presented in the conclusion. The I.P. survey was carried out between March 21 and March24, 1998, by crews of Rémy Bélanger Geophysics, of Rouyn-Noranda, Quebec.

Property description, location and access

The Sudbury Airport property is located in the central portion of Falconbridge township, in north-central Ontario, approximately 25 km to the northeast of the city of Sudbury and 4 km southeast of the Sudbury airport (N.T.S. 41 1/10).

The 736 hectare (46 units) property consists of eight contiguous mining claims situated in the central east part of Falconbridge Tp. in the Sudbury Mining District. The claim numbers are:
 

Access to the northern part of the property is from an unmaintained bush road running southeast from Highway 541 just past the Sudbury Airport. In winter a snowmobile trail crosses the claims.

Access to the southern part of the block is by All Terrain Vehicle over a series of trails leading from Ontario Hydro's Stinson Generating Station on the Wanapetei River. The Power Dam is accessed by a short all weather road from Highway 17 east of the regional Municipality of Sudbury. From the Power Dam Falconbridge Ltd.'s smelter water intake pipeline road is followed west to Emery Creek. A trail follows Emery Creek north along the Falconbridge/Street Township boundary. At about the third concession line a trappers trail runs west onto the claim block. In winter, the trail at the Falconbridge/Street Township boundary is a snowmobile trail. The trail at Emery creek may also be accessed by entering the main Gate at the Falconbridge Smelter and following the water pipeline road east.

Please refer to Figures 1. and 2., showing location maps of the area at 1:8,000,000 and 1:100,000 scales. The geophysical maps (not included but these can be viewed by appointment, email us) at 1:5,000 scale appended to this report show the property boundary, claim lines and the claim numbers.

Description of the I.P. surveys

The Induced Polarization survey was carried out over selected portions of a grid. This grid consists of cut survey lines, oriented at 090°, spaced every 100 meters and chained/picketed every 25 meters. The grid is divided in two sub-grids. In concession IV (south half of the grid) a north-south base line (B.L. 0+00E), striking at 000°, was used to set off the grid line, with tie lines 800W and 800E established to control the line's deviations. In concession V (north half of the grid), a different north-south base line (B.L. 0+00E), located 1200 meters to the west of the first one and striking at 000°, was used to set off the grid line. The present I.P. surveys were performed on lines l0S, 7S, 3N, 5N, 7N, 10N, 12N, 14N, 16N, 18N, 20N, 22N and 24N.

The I.P. survey was conducted using a dipole-dipole electrode configuration. The dipole dimension was 50 meters and successive separations at multiples of n=1, n=2, n=3, n=4, n=5 and n=6 times the dipole dimensions were used, in order to investigate at depth.

A total of approximately 16.4 line-km of I.P. data was thus gathered by contractor Remy Belanger of Rouyn-Noranda, Que'.

The I.P. equipment consisted of 1) a Phoenix IPT-1 transmitter operating at 1.0 Hz, powered by a 2 kW MG-2 motor generator. The phase-shift angle (in milliradians) between the transmitted current and the received voltage was measured by 2) a Phoenix Turbo V-5 phase I.P. receiver, measuring also the apparent resistivity of the earth at each "n". The phase angle is a direct measure of the polarization of the underlying earth.

The results of the I.P. surveys are presented in the appendix, namely in the form of pseudo-sections of the apparent resistivities and the measured phase angles, at the scale 1:5,000 and also on plan maps at 1:5,000, showing respectively the contours of the apparent resistivity at n=1, and the contours of the Phase (I.P. effect or polarization) at n=1, both displaying the interpreted I.P. anomalies, using symbols which are explained in the accompanying legend.

Results and interpretation

The Induced Polarization method is probably the best geophysical prospecting tool when investigating for base or precious metals in geological and structural environments such as the Sudbury Airport property area.

Indeed, the I.P. technique is capable of mapping most types of metallic sulfides, even when they do not conduct, which is often the case with Ni-Cu-Au mineralization associated with disseminated and stringer sulfides in fractures and breccias.

Furthermore, the I.P. technique can also discriminate between "poor" E.M. (i.e. MaxMin) conductors associated with electrolytic conductivity such as porous shear zones and overburden depressions (no I.P. effect), and "poor" E.M. conductors caused by low-conductivity metallic mineralization, such as stringer sulfides or sphalerite-enriched sulfides (recognizable I.P. effect). Its performance is occasionally hampered by conductive cover such as lacustrine clays and by resistive glacial sand cover (eskers) and also by sources of man-made cultural noise, when present.

In mafic crystalline rocks such as magnetic gabbros, it must be kept in mind that zones of massive magnetite may sometimes give rise to substantial I.P. effects, as crystalline magnetite can and will polarize.

The apparent resistivity measurements often provide very useful structural information and greatly help in mapping major lithological contacts and faults (the latter usually expressed as more or less linear resistivity lows).

In this particular case, a 50-meter dipole dimension was chosen because of its penetration capability and its ability for outlining potentially large, deep and wide pyrrhotite-pyritechalcopyrite-pentlandite mineralized zones having a significant depth extent. With the n=6 expanders and considering the outcrop-related noise levels and the relatively thin overburden cover within the survey area, this 50-meter dipole-dipole I.P. survey should be able to successfully detect metallic sulphide mineralization in the bedrock to depths in excess of 100 meters.

The thickness of the overburden layer is quite variable within the survey area, but its largest range is not expected to exceed 25 meters, generally speaking.

Resistivity

The resistivity relief, as contoured on the 1:5,000 colour resistivity plan map (see map in appendix), provides a quite faithful image of the overburden cover and of the bedrock surface's relief. About a quarter of the survey area particularly in the northwest, is characterized by low apparent resistivities (<500 ohm-meters), in great part contributed by conductive overburden in bedrock valleys.

The prominent crescent-shaped low resistivity zone between lines 300N and 2200N in the northwest coincides with the low-conductivity trend "M" on the earlier MaxMin survey. The absence however of any I.P. effect associated with this feature confirms its electrolytic nature, probably a wide shear zone.

The high resistivity (> 5,000 ohm-meters) areas are probably associated with bedrock ridges and subcrops. Quite often also, the definition of high resistivity zones provides help in outlining harder lithologies (more siliceous), sometimes a good tracer tool for metal-enriched environments.

These high resistivity zones and patches, making up about a third to half of the survey area, are distributed according to the colour resistivity contour map (see red shades on the resistivity map in the appendix) and appear to be more abundant in the central and southeast parts of the survey area. These high-resistivity areas form an overall linear ridge oriented at about 340° on the resistivity map and they should definitely be visited in the field, as there is a fair chance that more or new bedrock exposures will be found, hopefully helping in further understanding the geology and the structure of the property.

Polarization (I.P. )

The interpretation and compilation of the I.P. measurements indicate the presence of only a few truly anomalous polarization increases within the survey area. Referring to the I.P. pseudo-sections and the N=1 phase I.P. contour map and its accompanying legend, it can be observed that the I.P. anomalies were classified according to their "strength" (i.e. the probable "massiveness" of the causative metallic material) and their degree of definition (a well-defined I.P. anomaly is one which displays a clear, unambiguous triangular shape on a pseudo-section), as well as according to the behavior of the apparent resistivity.

Conductive, semi-massive and massive metallic mineralization (graphite and/or massive sulfides) will typically cause a notable decrease in the resistivity in addition to a strong I.P. anomaly. So will a mineralized shear corridor carrying disseminated or stringer sulphides. As the concentration of these metallic materials decreases, the drop in the apparent resistivity becomes more negligible but the I.P. effect still remains. The symbols used in the interpretation of the I.P. survey are explained on the compilation maps and on the pseudo-sections.

The induced polarization measurements show the presence of a number of features exhibiting moderately to strongly anomalous I.P. behavior. As can be seen on the pseudo sections and the Phase I.P. colour contour map, the most outstanding I.P. anomaly is located between 300N/1325E and 700N/1220E and it is open at both ends, This a first-priority target and it should definitely be drill-tested.

It is remarkable that the majority of the I. P. responses are located within high resistivity (thus outcropping or subcropping) domains. It may be tempting at first to call them "high background" anomalies, but a field verification is recommended nevertheless.

In a context of massive sulphide exploration, the following I.P. anomalies are definitely worth further investigation with diamond drilling:
 

Conclusion and recommendations

The Induced Polarization surveys which were recently completed for Millstream Mines Ltd.on a part of the Sudbury Airport property have successfu1ly mapped a number of anomalous zones characterized by an increased I.P. effect and presumably not known to date, some of which are quite "strong" and situated at relatively shallow depth.

There is an excellent chance that these I.P. anomalies originate from anomalous concentrations of metallic sulphide material (Py, Po, Cpy, etc.) in the bedrock and therefore the strongest ones certainly merit to be tested with diamond drill holes, gradually exploring toward deeper portions of the mineralization, as one gets to better understand the overall geometry and distribution of the sulphide mineralization.

The possibility for massive magnetite as the potential cause for some weak I.P. anomalies in areas of strong magnetic activity cannot be ruled out. Magnetic gabbros are well-known for their sometimes significant I.P. signatures.

Recommending further work on this property, and in addition to drill-testing the anomalies in the table above, it would be highly advisable to first visit all the high resistivity areas, in search for potentially new bedrock exposures that could allow stripping and trenching and thus obtain more samples and even possibly allow to explain a number of anomalous I.P responses.

In addition to the work proposed above, it is also recommended to pursue the I.P. surveys over the rest of the property and carry out in-fill I.P. surveys on the l00m spaced lines, in order to attain a better definition of the existing anomalies.
 
 

Rouyn-Noranda, Quebec Gerard Lambert, P.Eng

April 10, 1998 Consulting Geophysicist