Technical report. Ground TDEM PhiSpy Survey. Weedon Property, Lingwick area Estrie region, Québec 2017

Transcription

1 Technical report Documents complémentaires / Additional files Licence / License Ground TDEM PhiSpy Survey Weedon Property, Lingwick area Estrie region, Québec 2017 Énergie et Ressources naturelles Direction de l information géologique 28 juin 2017 GM Midland Exploration Inc. 132 Boul. Labelle, bur. 220 Rosemère, QC, Canada J7A 2H1

2 2 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 Prepared by Joël Dubé, P.Eng. February Décarie Drive Ottawa (Ontario) K1C 3K3

3 3 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 TABLE OF CONTENT I. INTRODUCTION... 4 II. WEEDON PROPERTY, LINGWICK AREA... 5 III. PORTABLE TDEM PHISPY SURVEY TECHNICAL SPECIFICATIONS... 7 FIELD OPERATIONS... 7 SURVEY EQUIPMENT... 7 TDEM METHOD PRINCIPLES... 9 IV. DATA PROCESSING AND PRESENTATION PHISPY TDEM DATA DELIVERABLES V. RESULTS INTERPRETATION AND DISCUSSION RECOMMENDATIONS VI. CONCLUSION VII. STATEMENT OF QUALIFICATIONS VIII. REFERENCES FIGURES FIGURE 1: GENERAL LOCATION OF THE WEEDON PROPERTY... 4 FIGURE 2: REGIONAL LOCATION OF THE WEEDON PROJECT... 5 FIGURE 3: DIGITAL ELEVATION MODEL WITH SURVEYED LINES AND MINERAL CLAIMS... 6 FIGURE 4: THE PHISPY PORTABLE GROUND TDEM SYSTEM IN ACTION... 9 FIGURE 5: PHISPY DATA OVER THE LINGWICK SHOWING TRENCH AND ASSOCIATED DRILL HOLES FIGURE 6: LINGWICK AREA PHISPY DATA OVER AIRBORNE TDEM RESPONSE FIGURE 7: LINGWICK INTERPRETATION OVER PHISPY DATA AND AIRBORNE TDEM RESPONSE TABLES TABLE 1: TABLE 2: TABLE 3: TABLE 4: GEOPHYSICAL SURVEY SCHEDULE AND PRODUCTION... 4 ACTIVE MINERAL TITLES COVERED BY THE SURVEY... 6 SETTINGS USED IN THE WINDOWING OF THE FULL WAVEFORM... 8 DELIVERED MAPS... 11

4 4 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 I. INTRODUCTION At the request of the mineral exploration company Midland Exploration Inc., Dynamic Discovery Geoscience Ltd. from Ottawa managed a ground time-domain electromagnetic (TDEM) PhiSpy survey on the Weedon Property (Figure 1), in January The survey was performed along roads and trails available in the area, and also through the bush, since the vegetation is generally sparse in the area. Details regarding the survey s schedule and production are provided in Table 1. The survey was conducted under the supervision of Mr. Joël Dubé, P.Eng. The goal of the survey was to identify geophysical responses possibly associated to sulphides mineralized occurrences. In particular, the survey aimed at detecting possible extensions of the Lingwick showing which was trenched in 2006, returning values of up to 1.4%Cu, 4.6%Pb, 13.5%Zn, 208g/t Ag, 4.19g/t Au. This showing is found only 500m to the south of the Lingwick mineralized occurrence discovered in 1932 and worked by Soquem in the 1970 s. In 2015, two holes were drilled to test the showing at depth. Both holes did intersect disseminates sulphides (up to 7% of combined pyrite, chalcopyrite and pyrrhotite), but no significant base metals values (St-Cyr, 2015). Figure 1: General location of the Weedon Property Table 1: Geophysical survey schedule and production Method Date Production PhiSpy TDEM km

5 5 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 II. WEEDON PROPERTY, LINGWICK AREA The Weedon Property consists of a block of mineral claims (Figure 2) located within NTS mapsheet 021E11 and 021E14. It is located near the village of Weedon, about 50 km north-east of Sherbrooke, in the Estrie region, Québec. It encompasses the past producing Weedon and Cupra-D Estrie mines. The area that has been worked is referred to as the Lingwick area, and it hosts the Lingwick mineralized occurrence, as indicated in the database of Québec s Ministère de l Énergie et des Ressources Naturelles (MERN). The property can be accessed via the Fontainebleau and Bourque roads. The Lingwick area that has been the subject of the survey is shown in purple in Figure 2. Figure 2: Regional location of the Weedon Project

6 6 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 The PhiSpy TDEM survey has been carried out near the Lingwick showing that has been unveiled by Midland Exploration in Given the relatively sparse vegetation in the area and other constraints, it has been decided to carry out the survey without cut lines. Roads and trails found in the area have also been surveyed, for a total 7.69 km. The PhiSpy survey path is shown in pink in Figure 3. The survey crew was based in Weedon. The active mineral claim titles that have been covered by the PhiSpy TDEM survey are also shown on Figure 3, and listed in Table 2. Table 2: Active mineral titles covered by the survey NTS map sheet Mining claim 021E E E E Figure 3: Digital elevation model with surveyed lines and mineral claims

7 7 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 III. PORTABLE TDEM PHISPY SURVEY TECHNICAL SPECIFICATIONS Field Operations The portable ground TDEM PhiSpy survey, totalling 7.69 km, was carried out in 1 day (Table 1), under the technical supervision of Joël Dubé, P.Eng. Since the system used is selfcontained and records its location continuously, it does not necessarily require to be carried out along chained lines. Lines do not necessitate being very straight as is the case for classic methods involving long wires such as the IP and HLEM methods, and field obstacles can be avoided as a result. Given the sparse vegetation found in the area, lines were not cut for this survey, which could therefore be carried out at lower cost. The survey was also performed along available roads and trails. The data was recorded in continuous mode at a final sampling rate of 5Hz, resulting in an average sample spacing of 0.14 m and a total of 48,549 data points collected. Survey Equipment The equipment used for the portable ground TDEM survey was the PhiSpy system which is being developed and employed by in partnership with Xogenus, in Ottawa. The system is powered by light weight batteries, and consists of a horizontal transmitting loop of 44 by 77, in the centre of which a horizontal (co-axial/coplanar), small size receiver loop is located to record the Z component of the EM field. The single-turn transmitter loop, with its 3.67 m 2 effective area and 1200 A current, yields a dipole moment of 4404 NIA. The transmitter generates alternating 586 µs half sine pulses followed by off-time durations of ms, at the rate of 30 pulses per second. The base frequency (full cycle) is therefore 15 Hz. The acquisition sampling rate of the EM field is Hz. In post-processing, data is later stacked, processed and down sampled in order to output a full data cycle at 5Hz. The receiver coil, centered within the horizontal transmitter coil, measures the vertical component of the EM field. It is made of 560 turns with an area of m 2, for an effective area of 32.2 m 2. Use of advanced technology enables reduction of the primary field at the receiver location, and permits on-time recording. The depth of investigation of the system has been estimated to be m, and the lateral resolution is metric. The timing relating to each sampling window with respect to the start of the pulse is shown in Table 3.

8 8 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 Table 3: Settings used in the windowing of the full waveform Wnd # Start (µs) End (µs) Pulse Wnd # Start (µs) End (µs) Pulse Wnd # Start (µs) End (µs) Pulse ON OFF OFF ON OFF OFF ON OFF OFF RAMP OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF The PhiSpy system is an innovative exploration tool. Contrary to large loop configurations requiring significant material and staff, the PhiSpy unit can be deployed rapidly and at low cost. It weighs about 40 kg and is operated by two persons (Figure 4). Its small size and the recording of location with a coupled GPS system (Trimble Yuma device with SBAS real-time corrections) enable its use in sparse forest, without the absolute necessity to have lines cut. This is not the case with other TDEM systems or co-planar Horizontal Loop frequency EM systems (HLEM, also known as Max-Min). In addition, the EM response is recorded with an improved resolution over these technologies, both because the sampling is nearly continuous and because of the loop configuration and size. The large screen of the unit has a map where the current location of the unit and other geoscientific information (such as targets from an airborne geophysical survey) can be visualized, enabling easy navigation to, and proper coverage of, areas of interest. In addition, the large screen enables real-time display of TDEM profiles, thus on the spot anomaly detection. Shallow anomalies can then be stripped, investigated and sampled right away. Unlike small size EM devices with very

9 9 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 limited investigation depth, PhiSpy can reach much deeper conductors and records full TDEM decay curves which can be post-processed and analyzed to retrieve information about the conductance and geometry of conductors. Figure 4: The PhiSpy portable ground TDEM system in action TDEM method principles The variable current in the coil produces an electromagnetic field. Termination of the current flow is not instantaneous, but occurs over a very brief period of time (a few microseconds) known as the ramp time. The time-variant nature of the primary electromagnetic field, which propagates downward and outward into the subsurface, induces Eddy currents which characteristics are governed by rocks conductivity distribution. They will be particularly strong in the presence of good quality conductors such as sulphide or graphite mineralization. These Eddy currents generate a secondary electromagnetic field, in accordance with Faraday's Law. This secondary field immediately begins to decay following the sudden termination of the primary field. Measurements of the secondary field only are made during the time-off period by a vertical component receiver located in the middle of the transmitter loop. Depth of investigation varies slightly depending on the time interval after shutoff of the current, since at later times the receiver is sensing EM field from Eddy currents at progressively greater depths. The off-time data can be analyzed in the form of profiles (Figure 5) or be geographically summarized by interpolating data from a single window to produce a data grid which can be displayed on a plan map (Figures 6)

10 10 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 Figure 5: PhiSpy data over the Lingwick showing trench and associated drill holes IV. DATA PROCESSING AND PRESENTATION Data compilation including editing and filtering, quality control (QC), and final data processing was performed by Joël Dubé, P.Eng. Processing was performed on high performance computers optimized for quick daily QC and processing tasks. Geosoft software Oasis Montaj version was used. PhiSpy TDEM data Results from the ground TDEM PhiSpy survey are shown in the form of a grid of an early offtime channel (Ch. 7), which effectively maps conductor s location (Figure 6). In order to preserve the high resolution (metric) provided by the nearly continuous recording of the PhiSpy and by its small footprint, grids are presented with a very high resolution (1 m cell size) and only at short distance from the readings location (5 m), as to avoid unstable interpolation of such high resolution data across survey lines further away. This also leaves freedom to the final data user to conduct interpretation of anomalies interconnections between the lines as local geological information is gathered. Given the limited penetration depth of the PhiSpy system, anomalies identified in this manner can be seen as a reliable image of the sub-outcropping part of detected conductors. Regarding the width of PhiSpy anomalies, it is important to note that the thickness of the conductive source generating an anomaly is always less than the apparent width of this anomaly. Note that in order to support the integration of geophysical data acquired on the property, and in an attempt to help interpretation efforts, the early off-time TDEM response from the heliborne survey performed over the Property in 2008 (Bournas, 2008) by Geotech is shown in the background of PhiSpy results (Figure 6).

11 11 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 Figure 6: Lingwick area PhiSpy data over airborne TDEM response Deliverables The maps created to present the information extracted from the survey are summarized in Table 4. All maps are referenced to the NAD-83 datum in the UTM projection Zone 19 North, with coordinates in metres. Maps are at a 1:2,500 scale and are provided in PDF, PNG, GeoTiff and Geosoft MAP formats. Digital data are also supplied for all the parameters recorded during the survey. The databases are delivered in the Geosoft GDB format. As well, the data grids created for mapping purposes are included in the deliverables. They are referenced to NAD-83 in the UTM projection Zone 19 North, with coordinates in metres. The grids are provided in Geosoft GRD format. Table 4: Delivered maps No. Name Description 1 DEM+SurveyPath+Claims Geographic location of survey lines and mining claims 2 PhiSpy Early off-time TDEM response from PhiSpy survey over airborne TDEM 3 Interpretation Integrated interpretation

12 12 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 V. RESULTS INTERPRETATION AND DISCUSSION In order to guide the follow-up of ground TDEM PhiSpy anomalies, the early off-time data have been analyzed in profiles to identify conductive anomalies. For this project, 4 different anomaly classes have been defined. The cultural confirmed class refers to anomalies originating from cultural features (metallic culverts, sign posts, fences or pieces of equipment) that have been seen on the field. The cultural likely class refers to anomalies with a response typical of cultural sources (high frequency anomalies with slowly decaying TDEM off-time channels) and/or that are found along roads and trails, but that have not been visually confirmed as pertaining to cultural sources. The marginal class represents anomalies that are only slightly above the noise threshold of the TDEM system. These anomalies are not strong enough to deserve follow-up, but they have still been identified in case some of them would be located in areas of interest based on other geoscience data, in which case they could be investigated. The weak class refers to anomalies rather weak, but reasonably well defined and strong enough to be worth investigating. Note that, despite the best effort analysis of the TDEM response, it is still possible for weak and marginal anomalies to be caused by cultural sources, and, likewise, it is also possible for cultural likely anomalies to originate from geological sources. It is also important to mention that the vegetation was particularly dense in a local area towards the south. This resulted in the TDEM system being tilted away from the optimal horizontal plane, as well as hitting trees, most of the time in this area. In turn, this had detrimental effects on the data quality, and for this reason anomalies identified in this area are questionable and should not be relied upon. This area is clearly indicated by a dashed grey outline on the interpretation maps and figure. This stresses the fact that line cutting is preferable and recommended for carrying out this type of portable TDEM survey. Figure 7 shows all of the interpreted anomalies. Among them, only 3 were deemed strong enough to be classified as weak anomalies. The northernmost one corresponds to the mineralization of the Lingwick showing unveiled by the 2006 trench. The southernmost anomalies, located close to each other, are found near the WEE drill hole, in between the hole and the 2006 trench. Other marginal anomalies are found on either side of these two weak ones, describing a N-S to NNE-SSW striking conductor over a strike length of about 100 m. This conductor is considered the only one to deserve investigation, and for this reason has been defined as a follow-up target, indicated by the purple polygon filled with hatches. The interpretation of the conductor s location from one survey line to the next is based on observation of the local geophysical data trend, but remains subjective. Ultimately, the conductor s interpretation should only be relied upon along survey lines. The interpreted anomaly does not necessarily represent the true width of the conductive source, but can still be used with a high degree of confidence to investigate the source. It is important to point that the TDEM response amplitude is governed by three main factors: the conductivity of the source, the volume of the conductive source, and the

13 13 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 distance between the source and the TDEM sensor. The anomaly shape is also dependant on the geometry of the conductive source. The connectivity between the conductive minerals is definitely critical for a source to be conductive. As a result, disseminated sulphides occurrences are not necessarily responding to EM techniques. In this case, the weak anomalies are of high frequency and low amplitude, and are decaying rather rapidly, indicating that the sources are close to surface, of very limited thickness, and not very conductive. This is consistent with the fact that no airborne TDEM anomalies were detected in the area. This is also consistent with the mostly disseminated mineralization found so far in the local area of the 2006 trench and the 2015 drill holes. It is worth noting that the conductor proposed for follow-up is located about 20m from WEE s collar (along its azimuth), and about 29m from WEE s collar (along its azimuth). The WEE log indicates that disseminated sulphides were encountered in the hole and sent for analysis from 33 to 39 m along the hole, while it was from 66.5 to 85.5 m (with mention of pyrite, pyrrhotite and chalcopyrite estimated up to 7%) for hole WEE This indicates that it is very likely that the source of the PhiSpy conductor outlined has been intercepted by both 2015 drill holes. This also implies that the mineralization discovered in the 2006 trench has not been reached at depth by these two short holes, and that it therefore remains to be drill tested with a longer hole. Figure 7: Lingwick interpretation over PhiSpy data and airborne TDEM response

14 14 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 Recommendations Analysis of the newly acquired PhiSpy ground TDEM data and considerations for other geoscience data available in the area allow for three main recommendations. First of all, it is recommended to perform ground investigation of the PhiSpy anomaly located between the 2015 drill holes and the 2006 trench with basic stripping and prospection methods. This is a relatively low cost item which will allow a better understanding of the mineralization nature along the entire strike length of the detected anomaly, despite the fact that it is very likely that this conductor has been intercepted by both 2015 drill holes at shallow depth. Second, given the likelihood that the mineralization intersected in both 2015 holes relate to the PhiSpy conductors detected at short distance from the holes collars, it is believed that these two short holes have not reached the mineralization revealed in the 2006 trench. It is therefore recommend to perform a new, longer, drill hole to effectively test the 2006 trench mineralization at depth. Finally, the three following facts are prompting for a change in the geophysical approach for the search of mineralization in the Lingwick area. 1- The ground TDEM survey has detected only very few reliable conductors (of very limited potential with respect to sources size) in the area; 2- The airborne survey has not detected any anomalies in the mineralization s vicinity; 3-The mineralization discovered so far in the area consist mostly of disseminated sulphides and/or of mineralization dominated by non-conductive sphalerite (1.4%Cu, 4.6%Pb, 13.5%Zn, 208g/t Ag and 4.19g/t Au reported for the best sample from the 2006 trench). As a result, it is recommended to continue the geophysical investigation of the area with the resistivity/ip method which is better suited in this exploration context. The mineralization found so far shows that this area bears potential for VMS type deposits, and the use of a deep-penetrating IP/resistivity survey configuration (possibly coupled with a concurrent magnetotelluric survey) to probe the area at depth seems indicated despite the absence of airborne TDEM anomalies. While collecting geological information during follow-up efforts, it is recommended to proceed with systematic measurements of the physical properties (magnetic susceptibility and conductivity) of grab, channel and drill core rock samples, and to compare these results with chemical assays in an effort to better understand the geophysical signature of the mineralization of interest. This could lead to a better understanding of the available geophysical data and help refining the targeting approach in the area.

15 15 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 VI. CONCLUSION The ground TDEM PhiSpy survey that was conducted on the Lingwick area of the Weedon Project in January 2017 was only partly successful in meeting the survey objectives. It failed to detect extensions to the 2006 trench mineralization. However, it did detect a weakly conductive lineament in between the 2015 drill holes and the 2006 trench, as well as a few marginal conductive anomalies, and recommendations have been made for the follow-up of the main conductor and a better investigation of the trenched mineralization at depth. The survey also showed that the mineralization found in the trench is mostly not conductive, and poorly conductive at best. This and other geoscience information analyzed in this report are prompting for a change in the geophysical approach used for exploring the area. Respectfully submitted, Joël Dubé, P.Eng. February 13 th, 2017

16 16 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 VII. Statement of Qualifications Joël Dubé 7977 Décarie Drive Ottawa, ON, Canada, K1C 3K3 Telephone: I, Joël Dubé, P.Eng., do hereby certify that: 1. I am a Professional Engineer specialized in geophysics, President of Dynamic Discovery Geoscience Ltd, registered in Canada. 2. I earned a Bachelor of Engineering in Geological Engineering in 1999 from the École Polytechnique de Montréal. 3. I am an Engineer registered with the Ordre des Ingénieurs du Québec, No , and a Professional Engineer with Professional Engineers Ontario, No (CofA No ) and with the Association of Professional Engineers and Geoscientists of New Brunswick, No. L5202 (CofA No. F1853). 4. I have practised my profession for 17 years in exploration geophysics. 5. I have not received and do not expect to receive a direct or indirect interest in the properties covered by this report. Dated this 13 th of February, 2017 Joël Dubé, P.Eng. #122937

17 17 PHISPY TDEM SURVEY, WEEDON PROPERTY, LINGWICK AREA, QUÉBEC, 2017 VIII. REFERENCES Bournas, N., Report on a Helicopter-borne Versatile Time Domain Electromagnetic (VTEM) Geophysical Survey, Weedon, Gat 1 and Gat 2 Blocks, Maniwaki Areas, Québec, Canada; Report by Geotech Ltd. for Midland Exploration Inc. (Québec MERN GM63827) St-Cyr, R., Rapport de travaux Forage 2015, Propriété Weedon, Cantons de Weedon, SNRC 21E11, 21E14; Report by Midland Exploration Inc. (Québec MERN GM69301)