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BJÖRKDAL EXPLORATION
The Company acquired the mineral rights immediately surrounding the Björkdal Gold mine when it purchased Bjorkdalsgruvan AB. The exploration land package consists of 10 permits covering 19 square kilometres. In September 2007, Gold-Ore purchased an additional 9 permits covering 34.5 square kilometres from Lundin Mining. These permits are contiguous with the east and south boundaries of the original Bjorkdal permits. After initial evaluation, the Company allowed some of the smaller and less strategically important permits to lapse. Currently the exploration lands cover 53 square kilometres in 14 permits. The Ronnberget gold target is located in the northeast part of the exploration land package.
Property Geology
The Björkdal area is located in the eastern part of the Paleoproterozoic Skellefteå district. This 1.9 billion year old volcanic arc hosts close to 100 Zn-Cu-Au-Ag volcanic-hosted massive sulphide deposits (VHMS) of which 28 have been mined historically. The best known mine in this area is the famous gold-rich Boliden deposit, which is located just 12 kilometres from the Björkdal mine. The Skellefteå District covers an area 150 kilometres by 50 kilometres and is Europe's biggest gold belt.
The Skellefteå district consists of a lower volcanic sequence (Skellefteå Group) overlain by a younger sedimentary sequence (Vargfors Group). The 3 kilometre thick Skellefteå Group is composed of mainly felsic volcanic rocks and the upper part of the Group hosts most of the VHMS deposits. The supracrustal rocks of the Skellefteå District were later cut by a variety of intrusions including the Björkdal dome.
The gold at Björkdal is associated with centimetre to metre wide subvertical quartz veins within a biotite-altered granodiorite or intrusive dome. The gold mineralization is localized near the contact between the intrusive and the overlying Skellefteå Group. The veins mainly trend NE and NNE. The vertical extent of the veins terminates at the sediment-intrusive contact, however, the strike extent remains open. The gold is found both as free milling gold and is also associated with pyrite.
Property History
The Skellefteå Field mining district has been the focus of exploration for gold-rich polymetallic deposits since the discovery of the Boliden Gold Deposit in the mid-1920's. While developing the Björkdal gold deposit, Terra Mining collected till samples on the exploration lands, but did not continue with any diamond drilling or other activities.
In 1989 the French company, Cogema, entered into a joint venture (SGJV) with an arm of the Swedish Government, NSG, to conduct exploration for gold in the Skellefteå Field. Gold and tellurium anomalies were detected in surface tills during the early 1990's and follow-up work included mapping, geophysics, trenching and drilling of the till profiles.
In 1993, Cogema dissolved the SGJV and formed a new JV with the Boliden Mining Company. This JV conducted extensive, detailed exploration programs in the Ronnberget area. The work culminated in the drilling of approximately 100 diamond drill holes to test for Björkdal-styles of mineralization. The Boliden-Cogema JV was dissolved upon completion of the diamond drilling in 1997.
Exploration Plans
An airborne survey flown in 2000 delineated several strong electromagnetic (EM) conductors at the contact of the dominantly metavolcanic rocks of the Skellefteå Group and the metasediments of the Vargfors Groups. This contact is very prospective for gold and base metal mineralization. It is this contact that hosted the 4.5 million ounce Boliden gold mine. Ground geophysical surveys over the conductors will further define the targets prior to diamond drill testing. In several cases anomalous geochemical metal values are found in the glacial tills adjacent to the EM conductors.
The Company plans to contract a detailed, low-level airborne magnetic survey to begin in June. These types of surveys are used to map shear zones and other structures that may be associated with gold mineralization. Results of the survey will be integrated with the geochemical data to assist in selecting drill targets.
During 2009 a geochemical survey of the 50 square kilometres surrounding the mine employed a technique known as heavy mineral concentrates. This process physically captures and counts the gold grains that are in the glacial till. Microscopic examination of the grains can estimate the distance to the bedrock source of the gold grains. This program successfully outlined several areas containing highly anomalous pristine gold grains suggesting proximity to bedrock mineralization. Additional sampling will be conducted to further refine the targets.
Based on the results of the foregoing exploration work, the Company then plans to follow up with up to 3000 metres of diamond core drilling on the defined drill targets.
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