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Post by Franko10 ™ on Nov 29, 2004 8:47:58 GMT -5
99
REPORT ON THE DIAMOND EXPLORATION
POTENTIAL FIVE PROPERTIES IN THE
FORT a la CORNE AREA, SASKATCHEWAN,
ON BEHALF OF
FORT a la CORNE DIAMOND FIELDS INC.
ROBERTSHAW GEOPHYSICS
Saskatoon, SK
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Post by Franko10 ™ on Nov 29, 2004 8:53:13 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 8:57:55 GMT -5
Report on the Diamonds Exploration Potential of Five Properties in the Fort à la Corne area, Saskatchewan, on behalf of Fort a la Corne Diamond Fields Inc. P. Robertshaw, P. Geo. October 28, 2002 Robertshaw Geophysics i SUMMARY During 2001 and 2002, a land position totaling 247 708 ha has been assembled by a group of 5 companies in the Fort à la Corne kimberlite exploration area of central Saskatchewan. The dispositions are adjacent to the 74 known kimberlite bodies of the Fort à la Corne kimberlite field, where the Cameco/De Beers/Kensington Joint Venture and Shore Gold Inc. are currently engaged in advanced evaluation programs. The Fort à la Corne area kimberlites were discovered in a surge of exploration work beginning in 1988. Aeromagnetic surveys were used extensively as a cost-effective exploration tool, and the moderately- to strongly-magnetic kimberlite bodies were outlined rapidly. Exploration declined after 1995 when it appeared that uneconomic diamond grades were being encountered in drilling, particularly in comparison to the spectacularly high grades being reported at that time from exploration programs in NWT from areas which are currently the Ekati and Diavik mining camps. The last Fort à la Corne area kimberlite discovery (the small and weakly magnetic Smeaton kimberlite body) was drill tested in 1996. Several other weak aeromagnetic anomalies in the general area were found to be caused by sources other than kimberlite, but many remain untested. The geological framework of kimberlite emplacement and the present architecture of typical Fort à la Corne kimberlites are reviewed. Structures in the Sask craton Archean basement are proposed, which may have affected the localization of the 74 kimberlite bodies located to date. These structures and trends might be used to focus further exploration. As the kimberlite bodies are generally covered by approximately 100 m of glacial overburden, with no surface expressions or geochemical indicator mineral dispersion trains, exploration has relied heavily on geophysical methods. The application and effectiveness of various geophysical methods is reviewed. Airborne and ground magnetics have been used widely, and all of the known kimberlite bodies have been located through follow-up of magnetic anomalies. Gravity, resistivity, airborne EM, EM depth soundings and high resolution reflection seismic profiling have been tested over some targets and found to be effective, though more costly. Several high quality aeromagnetic surveys have been completed over portions of the 5 Fort à la Corne area properties, with some ground follow-up including drilling, in the public record. The results of aeromagnetic surveys covering approximately 87% of the claims are available in map form, while digital aeromagnetic data are available for a smaller region. A multi-phase program of exploration is proposed for the properties of interest to Fort a la Corne Diamond Fields Inc. This should commence with an analysis of the available high quality public domain aeromagnetic coverage for any magnetic features which might not have been adequately investigated. Geophysical screening (gravity or resistivity surveys) of any prospective anomalies would be followed by drill testing, if warranted. The search for possible non-magnetic kimberlite bodies would begin with systematic airborne resistivity mapping using the GeoTem EM system. This would be followed by screening of prospective anomalies, using gravity and ground EM/resistivity surveys, and ultimately by drill testing.
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Post by Franko10 ™ on Nov 29, 2004 8:59:05 GMT -5
Statement of Qualifications I, Philip Robertshaw, of Saskatoon, Saskatchewan, do hereby certify that: ♦ I am a consulting geophysicist with an office located at 111 Middleton Crescent Saskatoon, Saskatchewan, S7J 2W5 ♦ I am a graduate of the University of London, UK, with B.Sc (Honours) in Physics (1969), and M.Sc. in Geophysics (1970), and have been engaged in mineral exploration continuously since 1970. ♦ I am a member of: Professional Engineers and Geoscientists of Saskatchewan, with Permission to Consult Society of Exploration Geophysicists Geological Society of Canadian Institute of Mining Prospectors and Developers Association of Canada Geological Association of Canada ♦ I am the author of this report, which is based on fieldwork on portions of the properties and surrounding properties since 1988, publicly available information in Saskatchewan Industry and Resources Open Files, peer-reviewed publications, and news releases by companies active in exploration within this area. Although the information supplied to me and assembled by me is believed to be accurate, and all reasonable care has been taken in the completion of this report, I hereby disclaim any and all liability arising out of its use or circulation. While I stand behind my interpretations, I cannot guarantee the accuracy of the source information therefore the use of this report or any part thereof shall be at the user’s sole risk. ♦ I have been involved with kimberlite exploration in the Fort à la Corne area since 1988, in the position of Chief Geeophysicist with Uranerz Exploration and Mining Limited from 1988 to 1998, and since 1998 as a consulting geophysicist. ♦ As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43-101. ♦ I have no direct or indirect interest in the properties discussed in this report, or in the securities of Fort à la Corne Diamond Fields Inc., nor do I expect to receive any. ♦ Permission is hereby granted to use this document as a technical report for the purpose of a private or public financing, or for other such suitable purpose. My written permission is required for the release of any summary or excerpt. Dated and Sealed at Saskatoon, Saskatchewan this 28th day of October, 2002. PROFESSIONAL SEAL ______________________________ Philip Robertshaw, M.Sc., P.Geo. ii TABLE OF CONTENTS 1 Introduction and Terms of Reference................................................................................... 1 2 Disclaimer........................................................................................................................... 1 3 Property Description and Location ....................................................................................... 2 3.1 Tenure.......................................................................................................................... 2 3.2 Other Regulations Governing Mineral Dispositions........................................................ 2 3.3 Current Mineral Disposition Status ................................................................................ 3 4 Accessibility, Climate, Local Resources, Infrastructure and Physiography ........................... 4 5 History ................................................................................................................................ 5 5.1 Diamonds exploration in Central Saskatchewan............................................................ 5 5.1.1 Sturgeon Lake......................................................................................................... 5 5.1.2 Fort à la Corne........................................................................................................ 5 5.1.3 Candle Lake............................................................................................................ 6 5.1.4 Shore Gold (Star kimberlite).................................................................................... 6 5.1.5 Smeaton ................................................................................................................. 7 5.1.6 Foxford.................................................................................................................... 7 5.1.7 Snowden South....................................................................................................... 7 5.1.8 Diamond-related Exploration Expenditures ............................................................. 8 5.2 Prior Exploration Work within the 5 Properties of Interest .............................................. 8 5.2.1 Aeromagnetic Surveys ............................................................................................ 9 5.2.2 Ground Magnetometer Surveys ............................................................................ 10 5.2.3 Drilling................................................................................................................... 11
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Post by Franko10 ™ on Nov 29, 2004 8:59:17 GMT -5
5.2.4 Drilling Results from the Snowden Kimberlites ...................................................... 13 6 Geological Setting.............................................................................................................. 15 6.1 Basement Geology..................................................................................................... 15 6.2 Crustal Structures........................................................................................................ 16 6.3 Phanerozoic Geology .................................................................................................. 17 6.4 Kimberlite Emplacement and Architecture ................................................................... 17 7 Deposit Types.................................................................................................................... 18 7.1 Economic Considerations............................................................................................ 18 7.1.1 Results from the FalC JV ...................................................................................... 18 7.1.2 Results from the Shore Gold Star Kimberlite......................................................... 20 7.1.3 Results from the Candle Lake JV.......................................................................... 21 8 Other Relevant Data and Information................................................................................. 21 8.1 Magnetics.................................................................................................................... 21 8.2 Gravity........................................................................................................................ 22 8.3 Resistivity .................................................................................................................... 23 8.4 Geotem Airborne Resistivity ........................................................................................ 23 8.5 TEM In-loop Soundings ............................................................................................... 24 8.6 Seismic Reflection Surveys ......................................................................................... 24 9 Interpretation and Conclusions........................................................................................... 24 10 Recommendations.......................................................................................................... 25 11 References ..................................................................................................................... 27 iii LIST OF FIGURES Figure 1: Property Location Map, Scale 1:6 000 000. Figure 2: Diamonds Exploration Properties, Prince Albert-Nipawin area, October, 2002. Scale 1:800 000. Figure 3: Fort à la Corne area properties, Eastern claims, October, 2002. Scale 1:200 000. Figure 4: Fort à la Corne area properties, Western claims, October, 2002. Scale 1:200 000. Figure 5: Aeromagnetic Surveys in SIR Open Files, Fort à la Corne area. Scale 1:500 000. Figure 6: Exploration Drillholes and Ground Magnetometer Surveys in SIR Open Files, Fort à la Corne area. Scale 1:500 000. Figure 7: Kimberlite bodies and drill hole locations in the Snowden area. Scale 1:100 000. Figure 8: Aeromagnetics with major lithotectonic features of the Precambrian basement. Scale 1:6 000 000. Figure 9: Basement structures interpreted from regional aeromagnetics, Prince Albert –<br>Nipawin area. Scale 1:500 000. Figure 10: Phanerozoic stratigraphy in the Fort à la Corne area. Figure11: Cretaceous stratigraphy with kimberlite emplacement intervals and marine transgression – regression cycles. Figure 12: Multi-layered kimberlite body. Figure 13: 2002 Exploration Proposal, Fort à la Corne area. Scale 1:500 000. LIST OF TABLES Table 1: Properties of interest ………………………………………………………………...…1 Table 2: Initial assessment requirements.…………………………………………………...…2 Table 3: Historic kimberlite exploration expenditures in Saskatchewan ………………..…6 Table 4: Aeromagnetic surveys in SEM Open Files ………………………………………..11 Table 5: Ground magnetometer surveys in SEM Open Files ………………………………13 Table 6: Snowden area drill holes (Fort à la Corne JV) in SIR Open Files LIST OF APPENDICES Appendix 1: Listing of Fort à la Corne area claims held by: Buckshot holdings Ltd. (50%) and Commando Holdings Ltd (50%) 101010307 Saskatchewan Ltd. 101012190 Saskatchewan Ltd. 101027101 Saskatchewan Ltd. Morgain Minerals Inc. 1 1 Introduction and Terms of Reference This report is prepared on behalf of Fort a la Corne Diamond Fields Inc., and is intended to document the status of kimberlite exploration activities in and around 5 properties which are located within the Fort à la Corne kimberlite field of central Saskatchewan. The 5 properties consist of 636 mineral claims with a total area of 247 708 ha (611 625 acres), which are currently wholly owned by others, as listed in Table 1. Table 1: Properties of interest Registered Owner Number of Claims Area (ha) Recording Date Buckshot Holdings Ltd. (50%) Commando Holdings Ltd. (50%) 318 78 177 March 2 and 9, 2001 101010307 Saskatchewan Ltd. 142 70 427 May 11, 2001 101012190 Saskatchewan Ltd. 106 81 568 August 16, 2001 101027101 Saskatchewan Ltd. 34 8 320 March 20, 2002 Morgain Minerals Inc. 36 9 216 March 20, 2002 No exploration work has been conducted on the 5 properties by the present owners. There are no known kimberlite occurrences within the 5 properties, but all are reasonably proximal to the 74 known kimberlite bodies of the Fort à la Corne kimberlite field. The geological setting and geophysical exploration characteristics of the Fort à la Corne area are discussed, providing a framework to assess the prospectivity of the properties for further kimberlite discoveries. The author has conducted and supervised exploration for kimberlites in the Fort à la Corne area since 1988, is familiar with the areas presently held under claim, and has visited and worked in portions of these areas during that period. Since kimberlites in this area are covered by 75 m to 150 m of overburden and have no surface expression, an additional field visit for the purpose of compiling this report was considered unnecessary. This report draws on compilations by the author of prior kimberlite exploration work (largely geophysical surveys and drilling) in the Fort à la Corne area, as available in the public domain. Sources of information are Saskatchewan Industry and Resources (SIR) Open File technical reports, peer reviewed publications and news releases by publicly traded companies active in the area.Diamond recoveries and evaluations from adjacent properties, reported by the Cameco/De Beers/Kensington JV, by Shore Gold Inc., and the Candle Lake JV, as available in Open File reports and news releases, are also discussed. 2 Disclaimer SIR requires that interpretive, technical reports must be filed to demonstrate the fulfillment of annual assessment expenditures to maintain dispositions in good standing. These reports (assessment reports) do not necessarily comply with National Instrument 43-101 standards and do not necessarily represent the entire amount of exploration work performed. Though diamond recoveries from Fort à la Corne area kimberlite bodies are noted where relevant, their economic significance is beyond the intended scope of this report.
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Post by Franko10 ™ on Nov 29, 2004 9:00:22 GMT -5
3 Property Description and Location The 5 parcels of mineral dispositions of interest to Fort a la Corne Diamond Fields Inc. were registered between March, 2001, and March, 2002, as listed in Table 1. In aggregate, the claims comprise a substantial and largely contiguous land position in a favourable exploration setting in the vicinity of the Fort à la Corne kimberlite bodies. In all, the 5 properties consist of 636 claims with a total area of 247 708 ha (611 625 acres). A complete listing of the claims, areas, ownerships and recording dates is attached as Appendix 1. The 5 properties are located in central Saskatchewan (Figure 1), within 100 km of the City of Prince Albert, and are largely accessible by road. The individual properties are identified in Figure 2 (1:800 000 scale), in relation to other exploration holdings within the Fort à la Corne area. In Figures 3 and 4 (1:200 000 scale), the individual claims are further identified. For reference, the outlines of the known kimberlite occurrences are shown in Figures 3 and 4. 3.1 Tenure Saskatchewan mineral dispositions are administered by Saskatchewan Industry and Resources (SIR). The 5 properties fall entirely within the surveyed portion of the province and require an annual exploration expenditure of $12 per hectare, after the first year, to remain in good standing. Claim holders must submit evidence of allowable expenditures, or post a deficiency payment or bond in lieu, within 90 days of the anniversary date. The initial assessment amounts and due dates for the 5 properties are listed in Table 2. Table 2: Initial assessment requirements Registered Owner Area (ha) Due Date Amount Buckshot Holdings Ltd. (50%) Commando Holdings Ltd. (50%) 78 177 March 2 and 9, 2003 $938 124 101010307 Saskatchewan Ltd. 70 427 May 11, 2003 $845 124 101012190 Saskatchewan Ltd. 81 568 August 16, 2003 $978 816 101027101 Saskatchewan Ltd. 8 320 March 20, 2004 $99 840 Morgain Minerals Inc. 9 216 March 20, 2004 $110 592 During the 2003 calendar year, expenditures of $2 762 064 will be required to retain the claims. In 2004 and subsequent years (until 2012) the required assessment expenditure will be $2 972 496. 3.2 Other Regulations Governing Mineral Dispositions Claims are defined in terms of legal sections or subdivisions. Road allowances, typically 20 m in width, fall between sections and are separate legal entities. In November, 2001, Saskatchewan Energy and Mines (now SIR) amended the description of mineral claims in the surveyed portion of the province to allocate road allowances to adjacent claim holders so that claim coverage can be seamless. After ten years the annual expenditure requirement increases to $25 per hectare. Grouping of contiguous claims is allowed to a maximum block size of 10 000 hectares. Reports submitted in support of assessment filings are held confidential by SIR for a period of 3 years, or until the claims lapse if earlier.
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Post by Franko10 ™ on Nov 29, 2004 9:03:36 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:06:02 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:06:50 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:07:07 GMT -5
3.3 Current Mineral Disposition Status The competitive mineral property status of the Fort à la Corne area, as of October 1, 2002, is shown in Figure 2. The core property which contains 63 confirmed kimberlite occurrences is held by the Fort à la Corne (FalC) JV of Cameco/De Beers/Kensington, and has been maintained in good standing since the claims were acquired in 1988 and 1989. The JV currently holds 121 claims for a total of 22 544 ha. During 2001, the FalC JV sold 3 outlying blocks of claims containing 5 drill-confirmed kimberlite bodies located in the northern part of the trend, to Shore Gold Inc. The blocks are located near Weirdale (4 claims, 1024 ha in area, containing 2 kimberlite bodies), near Foxford (12 claims, 1088 ha in area, also containing 2 kimberlite bodies) and east of Birchbark Lake (5 claims, 320 ha in area, containing 1 kimberlite). Shore Gold Inc. have progressively increased their land holdings by staking around the margin of the Fort à la Corne area since 1995, in addition to the above mentioned purchases in the north part of the area. Shore Gold currently hold 125 claims with a total area of 28,432 ha. Shore’s Star Kimberlite body, which seems to be one of the more prospective kimberlites of the district, is located at the southeastern end of the Fort à la Corne kimberlite trend. One other small kimberlite body is located on Shore claims to the east of the Star kimberlite. Shore’s inventory of kimberlites (8 in all) consists of the 2 bodies at the southern end of the trend, together with the 5 kimberlites purchased from the FalC JV and a small body located near Foxford. Skeena Resources Ltd. hold an option to earn 70 % of the Weirdale, Foxford and Birchbark Lake properties. United Carina Resources Corp. and Consolidated Pine Channel Gold Corp. had sizeable exploration programs during the 1993-94 period, which included over 55 drill holes in the Montreal Lake – Wapawekka Lake area to the north, and the Torch River area east of Fort à la Corne. They have recently renewed their kimberlite exploration programs by acquiring sizeable properties in the wider Fort à la Corne area (January 2000) and claims adjacent to the Cameco/De Beers/Kensington kimberlite 122 (with Shane Resources, November, 2000) on the west side of the main kimberlite cluster. Notable properties are the Smeaton claim block (10 624 ha) which contains a drill tested kimberlite body, and the ‘Diamond Lady’ claim block which adjoins the east side of the main FalC JV property. United Carina and Consolidated Pine Channel currently hold 57 323 hectares in 267 claims. In 2002, PanTerra Exploration Corp. entered into option agreements to acquire a 60% interest in the Smeaton and ‘Diamond Lady’<br>claim blocks. I psco, who maintain claims in the vicinity of their 1950’s iron ore exploration project (the Choiceland iron deposit), have modestly persued diamonds exploration south of Choiceland since 1989. Ipsco recently added to their dispositions, mainly extending further to the east of the main Fort à la corne kimberlite cluster, and now control 79 largely contiguous claims covering 8795 hectares. Successor companies of Rhonda Mining, formerly a major participant, now hold 5 claims east of the Fort à la Corne main cluster and 1 small claim south of the Saskatchewan River, a total of 1088 hectares. Claude Resources, also a major participant during the mid ’90’s, is currently reduced to holding 1 claim (256 ha). I n December, 2001, Twin Oaks Management staked a 30 claim property (24 736 ha) near Foxford and northeast of Birchbark Lake. Currently, an area in excess of 100 km north-south x 80 km east-west, centred on the Cameco/De Beers/Kensington Fort à la Corne dispositions, is almost completely staked.
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Post by Franko10 ™ on Nov 29, 2004 9:07:29 GMT -5
4 Accessibility, Climate, Local Resources, Infrastructure and Physiography The property lies between 25 km and 100 km east and northeast of the City of Prince Albert, population 42,000, which is served by road, rail and scheduled air links. Provincial Highway 55 and a single track Canadian Pacific rail line, which link Prince Albert and the town of Nipawin, traverse the properties between Meath Park and Choiceland (Figure 2). A series of villages of which Smeaton (population 220) is the largest, are located along Highway 55. Paved Highway 120 (Meath Park to Candle Lake) and subsidiary roads provide access to the western portion of the properties. Highway 6, linking Melfort and Choiceland, is located on the east side of the claims. Highway 302 provides access to claims south of the North Saskatchewan River. A network of unpaved grid roads covers the agricultural belt which lies between the White Fox River and Highway 55, and extends irregularly north of Highway 55. Towards the west, farm land served by grid roads extends as far as 55 km north of Prince Albert. This is the northern limit of arable agriculture in this region of the province. Approximately 150,000 ha (60 %) of the combined disposition areas fall within agicultural land. The Fort à la Corne Provincial Forest occupies non-agricultural land between the White Fox River and the Saskatchewan River. North of Highway 55, most of the non-agricultural land is classified as Northern Provincial Forest. Some forest fringe areas are classified as underdeveloped Crown Lands and certain areas are subject to wildlife habitat regulations. Access within the forested areas is provided by a network of logging roads and 4WD trails. This region of the province falls within the boreal transition ecoregion which defines the gradation from the grasslands and aspen groves of the south to the true boreal forest of the north. Both the Fort à la Corne Provincial Forest and this region of the Northern Provincial Forest are generally mature forest, with a predominance of jack pine. Aspen, alder, white and black spruce, poplar and tamarack are found in local stands. The terrain is flat except for the deeply incised flanks of the North and South Saskatchewan River valleys in the south and an area of sand dunes in the southeastern part of the properties, near Highway 6. Elevations within the properties range from 450 m to 550 m ASL, rising gently towards the northwest. The highest elevations are found to the southwest of Candle Lake, within the Northern Provincial Forest. Climate data have recently been compiled by the University of Saskatchewan Geography Department as part of the Atlas of Saskatchewan project (1999). The climate of the Prince Albert region is described as humid continental, cool summers (Köppen temperature and precipitation classification). The annual mean temperature (100 year average) is 0.8°C.<br>Monthly mean temperatures vary from -19°C (January) to +17°C (July). The average annual number of hot days (30°C or higher) is 6. The average annual number of very cold days (-30°C or lower) is 29. The annual mean precipitation is 406 mm, with precipitation (0.2 mm or greater) in 21 days per year, on average. The uranium and gold mining operations of northern Saskatchewan are serviced in part by Prince Albert area businesses, and draw skilled labour form this area. Electrical power is generated nearby (the E.B. Campbell Hydro Generating Station on the Saskatchewan River west of Nipawin) and telecommunications infrastructure is in place. 5 5 History 5.1 Diamonds exploration in Central Saskatchewan 5.1.1 Sturgeon Lake The presence of kimberlite in Saskatchewan was unknown until Monopros, the Canadian subsidiary of De Beers, discovered an exposure during a regional prospecting program in 1987. The kimberlite was found in a gravel pit located in a terrace on the north shore of Sturgeon Lake, some 35 km northwest of Prince Albert. The find came to the attention of local prospectors in 1988 when Monopros set up a bulk processing plant at the site, and rumours began to circulate in the exploration community. Since kimberlites often cause magnetic anomalies, several companies conducted aeromagnetic surveys in the vicinity during the summer of 1988, and a number of anomalies were discovered within a few kilometers of Sturgeon Lake. The activity resulted in a considerable amount of staking. The Sturgeon Lake body ultimately proved to be a glacially transported raft of kimberlite measuring about 180 m x 110 m and 10 to 20 m thick, and underlain by about 40 m of overburden. In a 1988 ground magnetometer survey reported by Monopros (SIR Open File 73G08-0001), the Sturgeon Lake kimberlite is represented by an oval mag high with a peak value of 1700 nT above background. Monopros processed 226 m3 of kimberlite from 11 trenches on this body in 1988, and shipped a heavy mineral concentrate to their Thunder Bay laboratory. A few microdiamonds were recovered, but no macrodiamonds were reported. Monopros and others (Claude Resources, Corona Corp., Cameco Corp., Rhonda Mining Corp.) drilled additional targets of this type in the Sturgeon Lake area between 1989 and 1993, with mixed success. At least two smaller, rafted kimberlite blocks were confirmed, although no diamond recoveries are reported. All the Sturgeon Lake area claims were subsequently allowed to lapse. The original gravel pit exposure of kimberlite was restaked in May, 2000. An in situ source for the glacially transported Sturgeon Lake kimberlite blocks has not been identified. 5.1.2 Fort à la Corne During the 1988 staking rush, Uranerz Exploration and Mining acquired a large land position in the Fort à la Corne Forest area, some 60 km east of Prince Albert. The ground was chosen on the basis of aeromagnetic anomalies which were thought to resemble kimberlite-type targets, in the available GSC (1960’s era) regional aeromagnetic coverage. Twenty eight isolated contour highs were identified and staked. Subsequently, a detailed aeromagnetic survey of the area in 1989 revealed 73 prominent magnetic anomalies, of which 71 have so far been proven to be caused by kimberlite bodies (Lehnert-Thiel et al., 1992, Jellicoe et al, 1998). The main group of kimberlites is located within the Fort à la Corne Provincial Forest and forms a north-northwest elongated cluster approximately 32 km in length, extending from the Saskatchewan River to Highway 55 near Shipman, as shown in Figure 3. Smaller outlying kimberlite clusters occur near Weirdale in the west, near Foxford in the north and near Snowden in the northeast. The kimberlite bodies are grouped more densely in the south, and spaced out more irregularly towards the north. A grouping of very large kimberlite bodies occurs in the southern part of the trend, as shown in Figure 3. The sizes of the kimberlite bodies have been estimated from geophysical models, which indicate a range of 2.7 to 184 hectares. The mass of kimberlite at each body has also been estimated, using a conservative density value of 2.5 gm/cc, and ranges from 3 to 675 million
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Post by Franko10 ™ on Nov 29, 2004 9:08:09 GMT -5
tonnes. The cumulative kimberlite footprint area for the 71 bodies held by the FalC JV in 1998 was estimated to be 2818 hectares, and the total mass of kimberlite was estimated at 9.5 billion tonnes (Jellicoe et al., 1998). The Fort à la Corne Joint Venture between Uranerz and Cameco was formed in 1989. Monopros (now De Beers) joined the JV in 1992, followed by Kensington Resources in 1995. In 1998, Uranerz was acquired by Cameco. According to an October 15, 2002, news release by Kensington Resources, the project ownership is currently Cameco (15.5%), De Beers (42.25%) and Kensington (42.25%). The Cameco/De Beers/Kensington land holding currently (October, 2002) consist of 22 544 hectares in 121 claims. 5.1.3 Candle Lake In 1993, War Eagle Mining Co. and Great Western Gold Corp. acquired a block of ground immediately east of Candle Lake, covering an area approximately 70 km north-south x 60 km east-west, and beginning 6 km north of the northern-most kimberlite body of the Cameco/Monopros/Uranerz Fort à la Corne project. Early work by War Eagle and Great Western Gold included large scale aeromagnetic surveys, follow-up ground magnetometer surveys and drilling. Three kimberlite bodies (C28, C29 and C30) were intersected in 1994 (SIR Open File 73I-03-0005). Kennecott Canada optioned the property in early 1995. Further drilling indicated that bodies C29 and C30 were actually one elongated kimberlite body with a nonmagnetic central section. The C29/C30 body is estimated to contain in excess of 60 million tonnes of kimberlite, while body C28 is thought to contain about 6 million tonnes. A mini-bulk sampling program was completed on the C29/C30 body during the winter of 1998, with a total of 7.5 tonnes of kimberlite recovered. Diamond recoveries were deemed to be poor and Kennecott terminated their interest in the Candle Lake property in the fall of 1998 (Great Western Gold news release, November 26, 1998). The property was inactive until the summer of 2002 when Great Western Gold completed a drilling program of 3 NQ holes. The current ownership is Great Western Gold (80%), War Eagle Mining (20%). 5.1.4 Shore Gold (Star kimberlite) In December, 1995, a Crown Reserve covering the Saskatchewan River valley was released for staking. The land included two aeromagnetic targets immediately south of the Fort à la Corne JV claims which were widely known at that time, from numerous aeromagnetic surveys, to be kimberlite-type targets. The ground was acquired by Shore Gold Inc. and is currently held 100% by Shore Gold. Both features have proven to be kimberlite bodies, and the larger of the two targets has been named by Shore the ‘Star kimberlite’. Shore describe the Star kimberlite as over 4 sq km in area (with drill-defined thicknesses of at least 30 m), with a mass in excess of 400 million tonnes. These figures would place the Star kimberlite as the largest single kimberlite body in footprint area, and among the top five bodies in mass, of the Fort à la Corne district. However, as shown in Figure 3, many of the Fort à la Corne kimberlite bodies are comparable in size but for historical reasons are subdivided. Applying the Fort à la Corne JV practice, the Star kimberlite might be regarded as 4 or 5 coalesced bodies. Shore’s practice is probably more appropriate as the geological model has evolved from vertical diatremes to flat-lying crater facies material since the FalC JV numbering scheme was implemented. 7 5.1.5 Smeaton A very weak aeromagnetic anomaly was detected 10 km north of Smeaton in 1994 by The Saskatchewan Diamond Syndicate (Golden News Resources, Laminco Resources and Swannell Minerals). Golden News/Laminco/Swannell obtained ground mag coverage of the target in 1995. A 200 m-wide anomaly of 25 nT peak amplitude was located, in agreement with the aeromagnetic feature. The target was drilled by Laminco, Swannell and Calco Resources in 1996. Hole RS-1 was collared at the centre of the ground mag anomaly and intersected 90.7 m of kimberlitic material beneath 128.0 m of overburden. The hole ended in sandy mudstones, possibly Mannville Group sediments, at a depth of 248 m. Four samples of kimberlite core were tested for microdiamond content by caustic fusion, and none were found. The property was allowed to lapse in 2000. D.W. Ventures acquired the ground in June, 2000, and the expanded property is now wholly owned by United Carina Resources (50%) and Consolidated Pine Channel (50%). In 2000, a gravity survey was completed, followed by a program of 4 ‘H’ size drill holes. United Carina subsequently reported that 3 holes reached bedrock and intersected ‘several metres of subaqueous fragmental and marine worked kimberlite, intercalated with fine grained sediments’. No microdiamond or indicator mineral results have been released. PanTerra Exploration Corp. hold an option to acquire 60% of the 30-claim property which includes this kimberlite body. 5.1.6 Foxford Rhonda Mining intersected 34.5 m of kimberlite in a drillhole 3 km east of Foxford in 1993. Drillhole OFS93-012 was targeted at a very weak magnetic anomaly derived from a detailed aeromagnetic survey and subsequently confirmed by ground mag coverage. The kimberlite intersection occurs in Lower Colorado shales, 70 m below the bedrock surface. Three microdiamonds were recovered from 20.77 kg of core (SIR Open File 73H06-0003). Two follow-up holes were drilled by Kensington Resources in 1994. Due to a property ownership dispute at the time, these were collared in a road allowance 500 m further east and failed to intersect kimberlite (SIR Open File 73H06-0010). The kimberlite intersection of OFS93-12 is over 800 m south of two known kimberlite bodies of the Fort à la Corne JV, which are located north of Highway 55, east of Foxford (as shown in Figure 3). The kimberlite discovery location was held by Rhonda and later by Kimmswick Diamonds as a single, small (64 ha) claim, and was allowed to lapse in 1999. The ground was restaked by Active Engine in February, 2000, and is currently held by Shore Gold. 5.1.7 Snowden South In 1993, Rhonda Mining staked a group of claims immediately south of the Cameco/De Beers/Kensington Snowden claim block after a detailed aeromagnetic survey indicated the possibility of shallow magnetic features extending across the Cameco/De Beers/Kensington claim boundary. Three drillholes were completed by Rhonda Mining Corp. in 1993, 5 km southeast of Snowden. All three encountered tuffaceous and detrital kimberlite (thicknesses of 15 m, 9 m and 14 m) at the bedrock surface (approximately 110 m below surface). Indicator mineral chemistry and microdiamond analyses were performed on kimberlite core samples. A total of 21 microdiamonds were reported from approximately 100 kg of kimberlite. (SIR Open File 73H07-0018). A nearby follow-up drillhole in 1994 (OFS94-017) failed to intersect kimberlite. This hole was drilled to a final depth of 160.0 m after intersecting the bedrock surface at 112.86 m. The section containing the Rhonda drillholes, and an adjacent section to the east, is currently held by Anglo Minerals.
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Post by Franko10 ™ on Nov 29, 2004 9:08:43 GMT -5
5.1.8 Diamond-related Exploration Expenditures Annual mineral expenditure figures are compiled by Saskatchewan Industry and Resources. The expenditures relating to diamonds exploration since 1988 are compiled in Table 3. Table 3: Historic kimberlite exploration expenditures in Saskatchewan. Year Estimated Spending ($ Million) Number of Operators Number of Assessment Submissions 1988 2 1989 2.29 6 9 1990 1.75 7 8 1991 2.67 5 3 1992 4.20 7 10 1993 11.06 20 63 1994 10.14 22 64 1995 3.76 16 11 1996 5.72 13 7 1997 2.39 8 6 1998 1.06 8 1 1999 1.43 8 Subject to 3 yrs confidentiality period 2000 4.11 8 .. 2001 8.56 estimated .. The surge in exploration activity during 1993 and 1994 was largely driven by the availability of cheap, high quality aeromagnetic surveys. The southern third of Saskatchewan (south of latitude 53°N) had virtually no aeromagnetic coverage in the public domain at that time. Also, the 1960’s era regional GSC aeromagnetic coverage north of 53°N was seen as only partially effective. Kimberlite discoveries during this period were disappointing, amounted to the 2 bodies at the War Eagle/Great West Gold Candle Lake property, and the two apparently small kimberlite bodies at Smeaton (Golden News/Laminco/Swannell) and Foxford (Rhonda Mining). The Snowden south area extension of a Cameco/De Beers/Kensington JV kimberlite was also outlined (by Rhonda Mining) during 1993-94. During the mid 1990’s, in response to the high level of industry activity, GSC sponsored a program of aeromagnetic coverage of southern Saskatchewan. The program was jointly funded by GSC, the province (SGS) and industry partners. Seven blocks of new (digital) coverage were obtained and have been released as GSC Open Files. The existing analogue aeromag data of the 1960’s has been digitized and merged with the new coverage to provide complete aeromagnetic coverage of the province, as shown in Figure 8. Between 1997 and 1999, activities at the major Saskatchewan exploration projects declined to a low level. Kennecott withdrew from the Candle Lake project and activity by junior companies also subsided. Beginning in 2000, the Cameco/De Beers/Kensington JV and the Shore Gold projects have renewed and accelerated their exploration programs, although junior company activity remains weak. 5.2 Prior Exploration Work within the 5 Properties of Interest No kimberlite exploration work has been performed by the current property owners. Following are summaries of work performed by prior owners, which has been submitted to Saskatchewan Industry and Resources in fulfillment of assessment requirements. As such, the reports may not contain the results of all work actually completed. 9 5.2.1 Aeromagnetic Surveys SIR Open Files contain records of 6 aeromagnetic surveys which have been completed within and peripheral to the 5 properties of interest. Over 90 % of the properties are covered by these surveys. The results of each survey are available from SIR as paper prints of total magnetic field contour maps, and also in most cases as vertical magnetic gradient contour maps. Digital data files for only one survey, the 1996 Fort à la Corne JV Geotem test survey, are available from SIR. The aeromagnetic surveys are listed in Table 4, and the corresponding outlines are shown in Figure 5. Table 4: Aeromagnetic surveys in SIR Open Files SIR Open File Company Date of work Area Survey specs 73-0003 Skeena Resources 1990 Birchbark Lake Candle Lake #9 Candle Lake Wolftrap Creek Small blocks, 300 m line spacing 73H07-0010 Aaron Oil 1990 South Snowden 1063 line km, 200 m line spacing 73-0009 Rhonda Mining 1993 Regional 51,600 line km. 150 m, 200 m and 300 m line spacing. 73H-0004 73H-0005 Golden News 1994 Golden 1, 2, Rebitt Golden 4, 5, Torch R 5542 line km, 300 m line spacing. 12,631 line km, 150 & 300 m line spacing. 73H06-0007 Guardian/Mountain Province/Pallaum 1994 Strong Pine 1714 line km, 200 m line spacing 73H-0008 Uranerz 1996 Smeaton Geotem test survey 12 km x 4 km block 300 m line spacing The 1990 work by Skeena Resources involved fixed wing aeromagnetic surveys over four single claims covering targets picked from GSC regional aeromagnetics. The aeromagnetic surveys indicated broad mag high features which were interpreted as basement-type signatures. The targets were not drilled and the claims were allowed to lapse. The 1993 aeromagnetic coverage by Rhonda Mining consisted of several surveys which were merged together. Canagrad flew three detailed surveys (150 m and 200 m line spacing) over the Fort à la Corne JV area, covering most of NTS map sheet 73 H/7 and adjacent ground. Geoterrex flew a larger survey (with 300 m line spacing) over the surrounding area, extended particularly towards the east, and also several peripheral blocks. The combined Canagrad/Geoterrex coverage includes the portion of the properties lying to the east of, and including Range 23, and comprising 69% (171,000 ha) of the presently held properties. Contour maps of the combined mag coverage follow NTS sheet outlines at 1:50,000 scale. The survey results are presented on 38 sheets with both total magnetic field contours and vertical gradient contours. The Rhonda survey seems to be a high quality data set, and although not available in the public domain in digital form for further processing, the contour maps are a useful starting point to search for subtle anomalies.
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Post by Franko10 ™ on Nov 29, 2004 9:13:06 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:13:40 GMT -5
The 1994 Golden 2 and Rebitt aeromagnetic surveys by Golden News cover a further 20 % of the properties to the west of Township 23. The flight line spacing for these surveys was 300 m. Contoured total field and calculated vertical magnetic gradient maps at 1:50 000 scale are available in SIR Open Files. Some eastern portions of the properties lie within the Golden 4 survey area, which provides 150 m line spacing coverage. Contoured total field and calculated vertical magnetic gradient maps at 1:25 000 scale are available in SIR Open Files. The Golden 4 survey detected the weak anomaly 9 km north of Smeaton which was drilled in 1996 (Laminco/Swannell/Calco Resources) and found to be caused by kimberlite. The 1996 Geotem survey by Uranerz (Fort à la Corne JV) included aeromagnetics. The survey covers 10 known kimberlite bodies, which are all strongly magnetic, within a 12 km x 4 km block. The aeromagnetic and EM/resistivity data are available in digital form from SIR. 5.2.2 Ground Magnetometer Surveys SIR Open File records contain 17 reports with details of 34 ground mag surveys which have been completed since 1889 within and peripheral to the 5 properties. The survey locations are indicated in Figure 6. The corresponding Open File listings are contained in Table 5. The Agate Bay and Kennecott surveys (1994 and 1996, respectively) located broad mag features which were interpreted to be caused by deep magnetic features (> 600 m) which seem to be related to basement geology. The 1989 ground mag surveys by Uranerz were tests of broad aeromagnetic features, and all are described as caused by basement geology in Open File report 73H-0001. The Ipsco coverage located weak, sinuous magnetic features which were thought to be at bedrock depth (+/- 100 m), but were not confirmed by drilling, and were likely caused by features in overburden. Two of the four Skeena surveys were follow-up to single claim-size aeromag surveys, the remaining two were located on GSC aeromag highs. All four mag features were subsequently interpreted to be caused by basement. Rhonda’s Foxford-Shipman area ground mag survey located the weak mag high (14 nT peak) which proved to be caused by a small kimberlite body near Highway 55. Rhonda’s ground mag survey south of Snowden mapped the southern extension of a Fort à la Corne JV kimberlite body, later proven by drilling to be caused by up to 15 m thicknesses of kimberlite. The Rhonda ground mag survey on claims adjacent to the west flank of Fort à la Corne JV kimberlite 122 detected a weak mag feature, 400 m in diameter, in the northwestern segment of the coverage. The flank of the magnetic signature of the nearby kimberlite 122 was also noted. Rhonda’s ground mag surveys in the Candle Lake area, Birchbark Lake area, Alder Flats and near the Saskatchewan River seem to have been over basement features. The Laminco/Swannell/Calco ground mag survey north of Smeaton confirmed the presence of a small, weak anomaly noted in aeromagnetics. The ground mag anomaly was 25 nT in amplitude and 200 m in diameter, and was subsequently shown to be caused by a small kimberlite body.
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Post by Franko10 ™ on Nov 29, 2004 9:15:08 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:22:05 GMT -5
Table 5: Ground magnetometer surveys in SIR Open Files Company SEM Open File Date of work Area Agate Bay Resources 73-0006 1994 2 small blocks, west of Birchbark Lake Kenecott 73-0011 1996 11 km northwest of Candle Lake Uranerz 73H-0001 1989 Gronlid area, near Rhonda drillhole OFS93-005 7 km north of Snowden 14 km north of Snowden 7 km northeast of Snowden 15 km northeast of Snowden 5 km east of Choiceland Strong Pine area (south of Weirdale) Uranerz 73H06-0001 1992 3 blocks, 3 km to 6 km SE of Weirdale Ipsco 73H07-0007 73H07-0008 1989 1990 Edge of Choiceland iron formation. 4 small blocks, gradiometer survey, same area as 1989 work. Skeena Resources 73-0003 1990 20 km west of Candle Lake 10 km west of Candle Lake 3 km east of Birchbark Lake 3 km northeast of Meath Park Rhonda Mining 73H02-0003 1995 Saskatchewan River area, Twp 48, R 20. Rhonda Mining 73H06-0003 1993,94 Foxford - Shipman area, OFS93-012 kimberlite. Rhonda Mining 73H06-0004 1993 4 km south of Weirdale 5 km southeast of Weirdale 5 km northeast of Weirdale Rhonda Mining 73H06-0005 1993 2 km southeast of Birchbark Lake Rhonda Mining 73H06-0006 1993 8 km south of Weirdale Rhonda Mining 73H07-0013 1993 Alder Flats – area of drillhole OFS93-011. Rhonda Mining 73H07-0018 1993 South of Snowden – area of drillholes OFS93-002, -003, -004 and OFS94-17. Rhonda Mining 73H07-0024 1997 Adjacent to FalC kimberlite 122 Rhonda Mining 73H11-0002 1996 4 km south of Candle Lake Laminco/Swannell/Calco 73H10-0002 1995 9 km north of Smeaton. RS-1 kimberlite. 5.2.3 Drilling Saskatchewan Industry and Resources Open Files contain records of four prior mineral exploration holes within the Buckshot Holdings/Commando Holdings and 101012190 SK claims, and their locations are shown in Figure 6. One hole was drilled by Uranerz in 1992 and the remaining three holes were completed by Rhonda Mining in 1993. Other than the 251 drillholes that have been completed on the Fort à la Corne JV kimberlite bodies since 1989, and the 31 drillholes reported to date by Shore Gold at the Star Kimberlite property, an additional 14 exploration drill holes have been reported by other operators in the vicinity of the 5 properties. The locations of these exploration holes are also indicated in Figure 6. 12 One drill hole was completed within the present Buckshot Holdings/Commando Holdings property, as follows: • In 1993, Rhonda Mining Corp. completed drillhole OFS93-011 near the centre of Section 27, Twp 51, Rge 20, W2, (8 km south-southwest of Smeaton) which is presently held as claim S-134605. Rhonda developed a target at this site based on a broad feature in aeromagnetic coverage, further refined by a ground mag survey. The drillhole did not intersect kimberlite. The overburden depth was 124.9 m, and the hole ended at 401 m in Devonian Dawson Bay Formation limestones (SIR Open File 73H07-0013). The magnetic anomaly was probably caused by basement geology. Three drill holes have been reported within claims owned by 101012190 Saskatchewan Ltd., as follows: • Drilhole 503-01, located 6 km south of Weirdale, was located near the west edge of Section 16, Twp 51, Rge 22, W2. The collar location is near the north edge of claim S- 135079 and was intended to investigate a weak (40 nT) ground mag anomaly. The drillhole intersected 100 m of sandy overburden and ended in Colorado Group shales at a depth of 240 m. No kimberlite was intersected. The weak magnetic target seems to have been caused by magnetite concentrations in the overburden. (SIR Open File 73H06-0001). • A 1993 drillhole by Rhonda Mining (drillhole OFS93-013) was located 5 km eastsoutheast of Weirdale in the south half of Section 34, Twp 51, Rge 22, W2. The site is near the west edge of the present claim S-135084. The hole tested a broad mag high in ground mag coverage. No kimberlite was intersected. The overburden thickness was 125.65 m and the total depth of the hole was 290.0 m. The hole ended in unconsolidated sandstone of the Mannville Group. The mag target seems to have been a basement feature. (SIR Open File 73H06-0004). • Also in 1993, Rhonda Mining completed drillhole OFS93-015, located 8 km south of Weirdale in the south part of Section 9, Twp 51, Rge 22, W2. The hole was collared 2 km south of the 1992 Uranerz drillhole 503-01, and falls within the current claim S- 135076. The target was a broad mag high from ground mag coverage. The HQ size hole intersected 117 m of overburden and ended in poorly consolidated sandstone of the Mannville Group at a depth of 240 m. No kimberlite was intersected. The magnetic anomaly was probably caused by a basement feature. (SIR Open File 73H06-0006). The following drillholes are located adjacent to the 5 properties: • In 1993, Rhonda Mining, completed drillhole OFS93-012 in Section 5, Twp 52, Rge 21, W2 (3 km east of Foxford). The target was a weak ground mag anomaly described as a 14 nT peak, 35 m in diameter. The hole intersected a 34.5 m interval of kimberlite and intercalated sediments in Lower Colorado shales from 179.45 to 211.94 m. Depth to bedrock was 109.96 m. The hole ended at 299.0 m. A 20.77 kg sample of kimberlite yielded 3 microdiamonds. (SIR Open File 73H06-0003). In 1994, Rhonda and Kensington Resources drilled two more holes (KR94-16 and KR94-17) in the road allowance 500 m to the east of OFS93-012. The holes ended at
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Post by Franko10 ™ on Nov 29, 2004 9:22:26 GMT -5
302.0 m and 257.0 m depth, respectively. Neither of these holes intersected kimberlite. (SIR Open File 73H06-0010). • Three drillholes were completed by Rhonda Mining Corp. in 1993, located 5 km southeast of Snowden, in Section 5, Twp 52, Rge 18, W2, adjacent to a large kimberlite body on Cameco/De Beers/Kensington ground to the north. o Rhonda drillhole OFS93-02 encountered 15 m of tuffaceous/detrital kimberlite immediately below the overburden, from 102 m to 117 m. The hole ended at 160.6 m depth. o OFS93-03 cut 9 m of eruptive and detrital kimberlite material beneath 95.12 m of overburden. The hole ended at 154.8 m depth o OFS93-04 intersected 14 m of mainly tuffaceous kimberlite immediately below the overburden, from 94.4 m to 108.4 m. The hole ended at 160.6 m depth. Indicator mineral chemistry and microdiamond analyses were performed on kimberlite core samples. A total of 21 microdiamonds were reported from approximately 100 kg of kimberlite. (SIR Open File 73H07-0018). A nearby follow-up drillhole in 1994 (OFS94-017) failed to intersect kimberlite. This hole was drilled to a final depth of 160.0 m. The overburden thickness here was 112.86 m. • In 1991, Ipsco drilled 4 holes in Section 14, Twp 50, Rge 18, W2, about 20 km south of Choiceland. The holes reached a maximum depth of 134.0 m, sampling a few metres of bedrock in each case. Overburden thickness varied from 110.9 m to 126.8 m. No kimberlites were intersected. (SIR Open File 73H07-0009). The ground is still held by Ipsco. The location is adjacent to Buckshot/Commando claims S-134509 and S-134510. • In 1993, Rhonda Mining Corp. drilled OFS93-005 in Section 36, Twp 48, Rge 19, W2, located south of the Saskatchewan River and about 15 km northwest of Gronlid. The hole intersected bedrock at 137.2 m and reached a final depth of 197.97 m. Rhonda reported a 0.6 m-wide interval from 159.65 m as ‘kimberlite equivalent’ in the Lower Colorado Ashville Member. The interval contains bentonite and medium-grained sandstones containing kimberlite minerals (SIR Open File 73H02-0001). The drill target was a broad mag high which probably represents a basement feature. Rhonda’s assessment submission report mentions a ground mag survey but the survey data were not submitted. A small claim (64 ha) at this site is currently held by Forest Gate Resources. Shore Gold holds the immediately surrounding land. Buckshot/Commando claims are 2 km northeast of OFS93-005 and extend to the north. • In 1993, Rhonda Mining Corp. drilled OFS93-014 in Section 29, Twp 52, Rge 21, W2, located about 6 km north of Foxford and adjacent to the present Buckshot/Commando claim S-134758. The hole was drilled to a depth of 296 m, ending in Mannville Group sandstones, with no indication of kimberlite. The overburden thickness was 118.6 m. (SIR Open File 73H06-0005). After lapsing during the late 90’s the ground was restaked by Active Engine (February, 2000) and is currently held by Shore Gold. 5.2.4 Drilling Results from the Snowden Kimberlites A cluster of eleven kimberlite bodies occurs near the village of Snowden, adjacent to claims held by Buckshot Holdings/Commando Holdings and 101010307 Saskatchewan Ltd. The Fort à<br>la Corne JV completed 10 drillholes on the Snowden kimberlite bodies between 1989 and 1997. 14 The hole locations are indicated by black star symbols in Figure 7. Table 6: Snowden area drill holes (Fort à la Corne JV) in SIR Open Files SIR Open File Company Drillhole Year Overburden Top of Kimberlite (m) Kimberlite thickness (m) EOH (m) 73H-0001 Uranerz 613-1 1989 79.9 79.9 41.1* 121 73H-0001 Uranerz 601-1 1989 82.3 82.3 45.7* 128 73H07-0016 Uranerz 604-1 1993 82.3 82.3 97.4 200 73H07-0020 Uranerz 603-1 1994 89 89 207 300 73H07-0020 Uranerz 614-1 1994 141 141 175* 316 73H-0008 Uranerz 601-2 1996 84.5 84.5 128.5 216 73H-0008 Uranerz 613-2 1996 79 79 41.0* 120A 73H-0008 Uranerz 615-1 1996 120.5 166.5 181.5* 348.0 73H07-0026 Uranerz 605-1 1997 109.1 109.1 125.0* 234.1 73H07-0026 Uranerz 612-1 1997 75.0 75.0 57.3 164.6 Note: * Hole ended in kimberlite A Hole abandoned Drillholes 601-1 and 613-1 (1989) penetrated less than 50 m of kimberlite and were terminated in kimberlite. Seven microdiamonds were recovered from 88.5 kg of kimberlite obtained in hole 601-1. The 58.5 kg of kimberlite from hole 613-1 contained no microdiamonds. Drillhole 604-1 (1993, HQ core) intersected 97.4 m of mainly fine to very fine grained kimberlite with intercalated sediments in the lower 20 m of the intercept. No microdiamonds (or macrodiamonds) were recovered from the 199 kg of kimberlite obtained. 1994 drillhole 603-1 investigated the very strongly magnetic anomaly (1400 nT peak amplitude) which was predicted to be caused by a deep-going kimberlite body, possibly a diatreme. A 12”<br>diameter reverse circulation hole was drilled to 300 m depth, intersecting 207 m of kimberlite. The kimberlite is described as very, very fine grained. From 37.742 tonnes of kimberlite theoretically excavated, 28.82 tons of chips were retained. One macrodiamonds (0.27 ct) and one microdiamond were recovered from this hole. The effective grade was calculated to be l.51 cpht, although the samples size is too low for a meaningful grade value. Also in 1994, using the 12” diameter reverse circulation (RCA) method, drillhole 614-1 was terminated in kimberlite at a depth of 316 m due to drilling problems. This hole had intersected 175 m of kimberlite from the apparent bedrock surface at 141 m depth. The kimberlite was described as fine grained. The hole excavated a theoretical mass of 26.741 tonnes of kimberlite, of which 18.39 tonnes of sample were retained. Seventeen microdiamonds were recovered, and a grade estimate of 5.33 cpht was reported.
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Post by Franko10 ™ on Nov 29, 2004 9:24:08 GMT -5
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Post by Franko10 ™ on Nov 29, 2004 9:24:23 GMT -5
In 1996, a 5” diameter reverse circulation drill system was used for 3 holes. Drill hole 601-2 was intended to test the encouraging microdiamond count obtained in the 1989 drillhole. This hole intersected 128.5 m of kimberlite and provided 2.84 tonnes of retained sample. One macrodiamond and 24 microdiamonds were recovered, and the grade was estimated at 0.2 cpht. Drill hole 613-2 attempted to follow up the 1989 drilling at kimberlite 613. This hole was lost after hitting an artesian aquifer at 120 m depth. Forty-one metres of kimberlite intersection, with 1.036 tonnes of retained sample (very, very fine grained olivine kimberlite) had been acquired at that point. No microdiamonds were recovered and processing for macrodiamonds was not attempted. Also in 1996, 5” RCA drill hole 615-01intersected 181.5 m of kimberlite and was terminated in kimberlite at 348.0 m depth, which was the rated depth capacity of the drill. From a theoretical mass of 6.497 tonnes, 3.215 tonnes of kimberlite chips (>0.85 mm size) were retained. Microdiamond analyses were completed on 8 composite samples weighing 68.55 kg, and 3 microdiamonds were recovered. No macrodiamond processing was performed. 1997 drilling consisted of 5” rotary holes at targets 605 and 612. Drillhole 605-1 intersected 125.0 m of kimberlite beneath 109.12 m of overburden. The kimberlite was described as dominantly poorly-sorted, fine- to medium grained olivine kimberlite. From a theoretical intersected mass of 3.855 tonnes, kimberlite chips with a total mass of 2.087 tonnes were retained. Microdiamond recovery by caustic fusion was performed on 44 kg of material, and 9 stones were recovered. The calculated microdiamond density for the entire hole was 212.9 stones/tonne. Macrodiamond recovery was performed on 1.892 tonnes of kimberlite, and no stones were recovered. The 1997 drill hole 612-1 intersected 57.3 m of kimberlite at a depth of 75.0 m. The kimberlite interval consisted of interbedded altered kimberlite and kimberlitic sediments. The total retained kimberlite mass was 1.173 tonnes (representing 1.834 tonnes theoretical mass). 12.3 kg of samples were submitted for microdiamond analysis, and 1.082 tonnes of kimberlite were processed for macrodiamonds. No micro- or macro-diamonds were recovered. I ndicated overburden depths for the Snowden area seem to be highly variable. Several holes indicate depths in the 75 m to 89 m range, which are the lowest values within the FalC area other than for portions of the Star kimberlite body which is located in the fringe of the Saskatchewan River valley. Possibly some thicker overburden values from the Snowden area drilling may be due to overdrilling. 6 Geological Setting A generalized geological section in the Fort à la Corne area consists of approximately 100 m of glacial overburden, some 500 m to 600 m of unmetamorphosed Phanerozoic sediments, and underlying Archean crystalline rocks. The kimberlites discovered so far (other than glacially rafted blocks) are contained within the Phanerozoic sediments, and are typically at or a few metres below the base of the overburden. 6.1 Basement Geology The crystalline basement in the Fort à la Corne area is part of a belt of Archean and Early Proterozoic rocks, up to 600 km wide, which can be traced from South Dakota, through eastern
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