In 2007, the company progressed some of the kimberlite programs to the drill target ready, discovery stage, and advanced the potential near-term development at the Tshikapa and Badibanga alluvial projects.
The company has near-term potential alluvial development permits within the Tshikapa/Kasai alluvial diamond field (Tshikapa Project) in the Kasaï-Occidental Province, and also within a second major alluvial diamond field in the Mbuji Mayi region (Badibanga Project) in the Kasaï-Oriental Province.
Within the Tshikapa area project, Mwana controls over 40 km of diamond mineralized Kasai and Tshikapa River frontage within this diamond producing area of south-western DRC. The project is in a 70% partnership with two local Congolese companies, Terra-Z (Permits TZ1, TZ2, TZ3 and Tshikapa) and Mukeba (Permits M1 and M2). The project focuses on evaluating the alluvial flats and terrace gravel deposits lying along the river banks. In 2006 the geological modeling and target selection was completed. Testing in these regions is advancing with the objective of defining and developing a bulk mineable diamond operation.
The Terra-Z exploration targets include over 1 km2 of upper terrace targets, and over 2.0 km2 of floodplain deposits (creek beds, lower terraces and flats). Potential grades range from 0.20 to 0.5ct/m3 (higher localized grades), with diamond values of ~$85/ct for the area. The Belgium company Forminiere extracted over 1 million carats from this area between 1918 and 1960 from creek, terrace and flat deposits. Mwana is evaluating the remaining diamondiferous terrace gravels from the last Forminiere mine cuts which hosts up to 5.0m gravel thickness in places, as well as the old Forminiere mine tailing dumps. In addition, the virgin terrace deposits in the Terra-Z TZ2 permit are being investigated using 8-inch diameter drillholes as Forminiere extracted over 0.5 million carats from creek deposits on this permit between 1918 and 1952. Within the same permit, a pothole on a large island on the Kasai River has been mined by artisanal miners returning diamond grades of 300ct/m3. The plan is to also investigate the remainder of the island using geophysics and drilling to determine the existence of similar deposits.
The Mukeba permits host large alluvial flats and terraces mainly located on the west banks of the Kasai River. Mwana is currently sampling these deposits with 6-inch drilling and mini bulk sample pitting. Diamond-bearing gravel thickness is up to 3.1 m in places, and recovered grades have reached up to 0.96 ct/m3 for the terrace samples.
The Badibanga Project is SouthernEra’s second alluvial project and is located some 60 km to the northwest of Mbuji-Mayi. The project is 100% owned by SouthernEra and historical information reported by Forminiere, reports on 3.49 million carats delineated within the alluvial flat system known as the "Lubi-Lukula Triangle". The deposits were never mined by Forminiere. The historical Forminiere map indicates that the average diamond grades in the alluvial flats approximate 1 ct/m3 with average grades of individual flats on the Lubi River as high as 1.7 ct/m3. The highest individual sample pit was historically documented at 10.6 ct/m3.
The initial program is targeting an alluvial flat area, named Flats D-E and F, where historical information reports a diamond deposit approximating 1.28 million carats within the "Lubi-Lukula Triangle". The company is extracting and processing basal gravels from bulk sample trenches along the flats, and has determined that the basal gravel ranges in thickness from 0.50m to 2.50m, and the overburden from 3.0m to 5.5m. The diamond processing plant recovered a total of 3,124 diamonds totalling 348.11 carats from 174 m3 of this basal gravel, returning an average recovered grade of 2 ct/m3. The largest recovered diamond was 1.75 carats. The first phase program is continuing with the objective of extracting a representative parcel of over 2,000 carats for diamond valuation purposes. In addition to the extraction of the 2,000 carats, smaller bulk-sample pits averaging 10m x 10m in size will be sampled at 40m intervals along 200 m spaced lines across the rest of the flats to record accurate geological information, as well as highlight any grade or stone-size changes across the flats. Based on positive results from the first phase, the second phase will consist of methodical pitting and drilling to increase confidence levels in the resource and facilitate a decision to mine.
