Location
Serra Pelada is situated in the mineral prolific Carajas region near the towns of Curionopolis and Parauapebas, Para State, northern Brazil. Access and infrastructure are excellent (view regional geology).
History
Discovered in 1979, Serra Pelada hosted the largest ever gold rush in Latin America (view Serra Pelada Garimpo). During the 1980s, up to 80,000 garimpeiros (artisanal miners) produced an estimated 2 million ounces of gold plus platinum and palladium, from a 400m x 300m x 100m hand dug open pit. Garimpeiro production declined due to pit wall collapse and flooding causing the cessation of bedrock mining since the late 1980s.
Vale, which held the underlying title to Serra Pelada until 2007, explored the area from 1980 to 1998, completing more than 200 drill holes in the Serra Pelada mineralised system (view Serra Pelada, 2007).
COOMIGASP, a registered Brazilian cooperative company, was granted Exploration License 1485 (DNPM process 850.425/90) by the Ministry of Mines & Energy in February, 2007. This 100 hectare license is centered on the Serra Pelada pit (view Serra Pelada, 2007).
In July 2007, COLOSSUS and COOMIGASP formed a partnership to develop the remaining bedrock mineralisation at Serra Pelada. Under the terms of this joint venture, COLOSSUS will manage and operate the project, earning a majority interest by funding exploration and paying COOMIGASP a premium for the gold reserve established by the joint venture. Details of this agreement may be found in Colossus Minerals Prospectus on www.sedar.com. COOMIGASP will separately develop the ‘monteira’ (tailings and waste from the Serra Pelada garimpo), with initial financial and technical assistance from COLOSSUS.
Gold-Platinum-Palladium Mineralization
The Serra Pelada deposit is hosted by Archaean metasediments of the Rio Fresco Group which unconformably overlain by greenstone belts and gneissic basement, intruded by several ages of mafic-ultramafic and granitoid plutons (view local geology).
High-grade gold-platinum-palladium mineralization is hosted mainly by fine-grained carbonaceous rocks, but also occurs in iron oxide-rich breccias and silicified zones (Grainger et al, 2002). The deposit is oxidized to depths of around 300m. Consequently, sulfides are lacking and gold and PGE’s occur mainly as metals and alloys (Cabral et al, 2002).
The Central Mineralized Zone at Serra Pelada was mined along about 350m of strike length to depths of about 110m. Vale drilling in this area encountered some remarkable intersections. For example drill hole FD-0032, 43m. (from 40m) assaying 4709g/t gold, 204g/t platinum and 1174g/t palladium (Cabral et al, 2002) (view long section of open pit).
Vale drilling confirmed that gold-platinum-palladium mineralisation extends under the pit and for more than 450m strike length to the western boundary of 850.425/90. In these areas, mineralisation has been encountered at depths of 150-350m and constitutes the prime target of the COLOSSUS-COOMIGASP joint venture.
Tallarico (2000) and Vale (2006) modeled the Central Mineralized Zone as arcuate in form, with a steeply dipping eastern margin and more shallowly dipping limbs to the west (view cross section 00). The highest grades of gold, platinum and palladium occur in the moderately to steeply dipping parts of the central zone which is up to 150m in vertical extent and in places more than 50m wide (view mineralized column). Vale (2006) and COLOSSUS interpret the Central Mineralized Zone as occupying the hinge zone of a reclined syncline which plunges gently to the southwest. Additional noble metal mineralization occurs to the east and west of the central zone.
The geochemical character of Serra Pelada mineralisation (Cabral et al, 2002; Grainger et al, 2002) is consistent with its deposition by progressive reduction of highly oxidized brine(s) in a structurally controlled hydrothermal plumbing system postdating the main regional deformation of the Rio Fresco Group.
COLOSSUS-COOMIGASP program
Accomplished to date:
-
completed a detailed topographic survey including the capture of remaining Vale drill collar
-
acquired 45,000m of Vale drill core and advanced a program of re-sampling and re-assay program for gold, PGE’s and other elements of potential economic significance
- completed an initial resource delineation campaign comprising seventeen diamond drill holes for 5129 metres of coring (view Serra Pelada, 2007).
The gold-platinum-palladium assays for twelve of these Phase I drill holes may be viewed by clicking on the respective number, SPD-001, SPD-002, SPD 003, SPD-004, SPD-007, SPD-008, SPD-010, SPD-011, SPD-012, SPD-013, SPD-017 and SPD-018.
- Assays for two drill holes from current Phase II drilling program may be viewed by clicking on the respective number, SPD-020A and SPD-021.
- The context of these drill-holes may be examined by clicking on the following drill sections:
- developed a 3D geological model to guide drilling
Program for 2009:
- complete 10,000m Phase II diamond drilling and assaying for gold-platinum group elements
- assay Phase I and Phase II drill core for other PGE’s and other significant elements
- continue geotechnical program for development scenarios
- baseline environmental study
- metallurgical testwork
- prepare and file final exploration report with Brazilian authority
