Orex Exploration
Orex Exploration is a former Canadian gold mining company that conducted exploration work on mining properties it owned in the Goldboro and Guysborough County areas of Nova Scotia. The properties owned by Orex were the sites of the former Boston Richardson Mine, Dolliver Mountain Mine, West Goldbrook Mine, and East Goldbrook Mine which operated between 1892 and 1912. Headquartered in Rouyn-Noranda, Quebec, the company was founded in 1987 and raised funds for exploration work, in part, by issuing stocks traded on the Montreal Stock Exchange and then the TSX Venture Exchange. It became a subsidiary of Anaconda Mining Inc. after Anaconda acquired the company in a stock swap deal in 2017.
Property Description
Orex's Goldboro main property consisted of 37 contiguous claims held under license from the Province of Nova Scotia. It is located along the eastern shore of Nova Scotia and is wholly owned by Orex. The property is situated 185 kilometers northeast of Halifax and is accessible by a 2.5 kilometer unpaved road from Highway 316 which links the village of Goldboro, Nova Scotia to the town of Antigonish, NS. The main project location is found at Latitude: 45° 10´ North ; Longitude: 61° 40´ WestOn November 26, 2009, following a joint venture agreement with Osisko Mining, Orex staked hundreds of additional contiguous claims which cover 960.8 square kilometers surrounding the Goldboro strike area. The current map of these claims highlighted in yellow is below. Initial exploration on these claims is now underway.
Image:OrexClaims-15Feb2010.jpg|thumb|center|Orex Mining Claims as of February 15, 2010
Resource Estimates
In September 2009, Orex published a Mineral Resource Estimate compliant with National Instrument 43-101 standards. They presented the resource estimate with a variety of cut off grades, the two most notable are represented below:With a cut-off grade of 0.5 g/t Au, the Mineral Resource was as follows:
- 519,000 tonnes grading 3.08 g/t AU within the Measured category
- 7,414,000 at 2.06 g/t Au within the Indicated category; and
- 7,933,000 grading 2.13 g/t Au within the Inferred category.
The Results of the 2009 Mineral Resource Estimate with a cut-off grade of 1.50 g/t Au are as follows:
- 270,000 tonnes grading 4.99 g/t Au within the Measured category
- 2,441,000 tonnes at 5.99 g/t Au within the Indicated category; and
- 3,438,000 tonnes grading 3.67 g/t Au within the Inferred category.
'''A major issue with this estimate was that 96 DD samples used in previous reserve estimates were assigned a value of 0 g/t in the model due to less than complete historic sampling required for the new geological model being used. This resulted in a significantly lower than expected resource. Orex is currently resampling the areas that these holes covered as well as new areas.'''
Joint venture with Osisko
On November 12, 2009, Orex signed an option and joint venture agreement with Osisko Mining.The key terms of the agreement are:
- Osisko invested $1.3million in Orex and received 13,000,000 shares at a price of $0.10/share
- Osisko received 13,000,000 transferable warrants to acquire one common share at a price of $.125/share over a period of 3 years
- Osisko receives a 50% interest in the property before September 29, 2013 if it incurs exploration/development expenditures of:
- * $1,500,000 before September 29, 2010
- * $3.5 million on or before September 29, 2011
- * $8.0 million on or before September 29, 2013
- Osisko may receive a 60% interest in the property if it completes a prefeasibility study before September 29, 2015
On November 1, 2010 Orex reported that Osisko had incurred exploration and development expenditures in excess of the $1,500,000 minimum required by September 29, 2010. Osisko confirmed that it would continue to incur expenditures under the option and joint venture agreement. A drilling plan and budget for the next phase of the drilling campaign on the Goldboro Gold Property was to be prepared. In Osisko's March 31, 2011 MD&A the company reported that the cumulative expenditures on the Goldboro property was $2,928,000.
On September 29, 2011, Osisko and Orex jointly announced that Osisko had allowed its option on the property to expire by not meeting the minimum expenditure requirements. Osisko stated "While the results from the 2010 and 2011 drilling campaigns are encouraging, they indicate the presence of a smaller deposit potentially minable by selective underground methods focussed on the veins, or alternatively a relatively shallow open pit operation, both of which are outside the scope of Osisko's exploration and acquisition strategy."
Current exploration activities (2009 to 2011)
Joint venture exploration activities
On January 27, 2010 Orex and Osisko began their first joint exploration. A three-part campaign was planned with two drills. Osisko began with the 4,728 m / 18 holes Phase 2F drilling campaign, to some incomplete and/or non-compliant historic drill results with compliant data primarily in the deeper portions of the Ramp Area Mineral Resources and extending westward towards West Goldbrook. Following Phase 2F, Osisko continued with the Phases 2D and 2E drilling campaigns, which continued westward along the remaining 1.7 km segment of the Boston Richardson Deformation Zone from the Ramp through West Goldbrook to Dolliver Mountain.As of April 29, 2010 59 holes for the Phases 2D, 2E and 2F drilling campaign, representing 12,989 metres, were completed. A 600m undrilled gap still exists between West Goldbrook and Doliver Mountain.
During the same period Nova Scotia based Mercator Geological Services Limited and D.R. Duncan & Associates Ltd., were retained and completed a regional compilation-synthesis on the 960.8 km2 Goldboro Extension Property. A number of key Goldboro-type gold targets were identified and are currently being drill-tested using the Reverse Circulation method to recover basal till and bedrock samples for gold assaying and whole-rock analysis. To date 194 RC drill holes are completed for 1,513 meters and 758 samples taken.
On November 18, 2010 the highlights of 64 holes were released. Significant mineralization was found in 12 of them. Including four bedrock samples grading 2.3 g/t, 4.23 g/t, 10.85 g/t & 25.65 g/t.
On February 8, 2011 Orex management announced that Osisko would conduct further Diamond Drilling on 10 targets. Four holes to the west of the West Goldbrook strike area to validate the up-plunge of the West Goldbrook formation, and six east of the East Goldbrook area on a 750meter area of new prospects identified by the RC drilling. This drilling is to start in March 2011.
On April 20, 2011, Orex and Osisko announced drilling had commenced on three diamond drill holes spaced 200 m apart in the West GoldBrook to Dolliver Mountain gap where there has been no previous drilling. In addition six drill holes will be drilled on 3 sections spaced 250 m apart from East Goldbrook to the east property boundary. Reverse circulation drilling in 2010 indicated a trend of mineralization in this area. On August 11, 2011 Orex and Osisko announced the results from this drilling campaign. A total of 10 holes were drilled. Significant additional new mineralization was identified on the areas between East Goldbrook and the eastern Property Boundary including an intersection of gold that assayed at 1570 grams/ton over half of meter of core, and another sample of 410 g/t over 1/2 meter of core.
Independent exploration activities
In addition to exploration activities undertaken with Osisko, Orex is conducting field exploration activities on its many claims that are not shared with Osisko. These exploration activities are guided by the Regional Compilation study funded through the joint venture with Osisko. This information was officially revealed on November 30, 2010, although it had long been understood to be occurring by local residents and people close to the project.On November 30, 2010, further details of the company's field exploration activities were released. New mineralization was noted to on western claims on the Goldenville and Stillwater Claims, including the discovery of a quartz vein outcrop on the Goldenville Anticline which had a sample grading 12.665 g/t, and the discovery of a 12-metre-wide quartz vein 600 m to the south of this outcrop. The company also reported a float sample grading 0.121 g/t in an area close to the Stillwater anticline with historic anomalous gold occurrences. The company also announced that it had resumed field exploration work several weeks earlier.
Geological interpretation
The property is located within the Meguma Supergroup of the eastern Canada Appalachian Belt. The property is entirely underlain by sedimentary rocks of the Goldenville Group, which consist of altered greywacke, sandstone, and slate. The stratigraphic sedimentary succession of the Goldboro area is affected by the Upper Seal Harbour anticline. This anticline is an upright, ENE-trending tight fold with a 10° to 30° plunge to the east. In the apex of the anticline, the slate units are thicker than other sedimentary rock types. The following diagram illustrates the Goldenville & Upper Seal Harbor Anticlines and the relative location of gold mineralization being explored by Orex and Osisko:Image:OrexNewGoldLocations.jpg|thumb|center| 500px | Goldenville and Upper Seal Harbour Anticlines Annotated with Orex Gold Locations
The Goldboro mineralization has been previously referred to as a “saddle reef” lode-gold deposit type. In Nova Scotia, the Boston-Richardson mine is a classic example of a “saddle reef” deposit. The gold mineralization at Goldboro occurs in association with and within a quartz vein swarm located in the hinges of regional anticlines, principally in black shale-argillite wall rocks. As such, Goldboro is not a classic “saddle reef” lode gold deposit type. The fine-grained folded sedimentary units have a constant thickness in the limb but not in the hinge of the fold, suggesting flexural-slip as the folding mechanism. Many key features within the gold deposits of the Upper Seal Harbour district show that the folding itself should be considered as the gold mineralizing process.
Gold mineralization at Goldboro occurs in quartz veins and disseminated sulphides in the wall rock. The mineralized wall rock mostly, but not exclusively, consists of shale-argillite. Locally, the greywacke and arenite are cut by quartz veins and are mineralized. The veins are characterized by quartz, sulphide and native gold. Wall rocks generally contain more sulphides than the veins, in the form of arsenopyrite selvedges.
Exploration by Orex from 2005-2008 indicated that in certain portions of the sedimentary sequence the intervening sandstone rocks contained sufficient veining and mineralization that in combination with the shale/slate units formed large zones of lower grades that could possibly be mined by open pit methods.
The 2010 drilling is revealing further possible revisions to the interpretation as they see a strong subvertical influence in the location of mineralization probably along subvertical shear zone.
The shorter term focus has been the identification and delineation of the maximum number of low cost near surface potentially open pit resources. This would be followed by investigation of higher grade shallow and deeper resources for potential economically viable underground operations either independent or complementary to potential open pitting.