DMC Mining (ASX:DMM) has announced an increased exploration target size of 0.9 to 1.3 billion tonnes of dominantly itabirite iron mineralisation at its 80% owned Mayoko Iron Ore Project in the Republic of Congo in West Africa.
Mineral investment company Cape Lambert Resources (ASX: CFE) is DMC’s largest shareholder with 36% of the issued shares of DMC. CFE participated in a share placement in September 2009 at $0.25 per share.
Recently completed reconnaissance geological mapping and rock chip geochemical sampling has confirmed the occurrence of iron mineralisation at 3 new targets that were initially identified by a high resolution, airborne magnetic survey completed in 2009.
The targets were not included in the exploration target size previously announced of 0.7 to 1.0 billion tonnes at the Mt Lekoumou in Mt Mipoundi and Mt Lekoumou South Prospects.
Geophysical modeling of these 3 new targets, constrained by surface mapping and sampling, estimates an additional exploration target size1 of 200 to 300 million tonnes, which increases the aggregate exploration target size1 at the Mayoko Iron Ore Project by 30%, to a range of 0.9 to 1.3 billion tonnes of dominantly itabirite iron mineralisation.
The 2009 airborne geophysical survey covered 220km2 or 22% of the area of the granted Mayoko exploration licence. The Mbinda target is open along strike to the northeast. DMC plans to extend the airborne geophysical coverage of the Mayoko licence to the north and south with a survey to be undertaken later in 2010.
The high resolution airborne geophysical survey completed during 2009 totaled 2,402 line kilometers covering an area of 220km2 located in the central portion of the 1,000km2 Mayoko exploration license.
Reconnaissance geological mapping and surface rock chip geochemical sampling was completed at the 3 new targets, referred to as Mipoundi North, Mbinda and Doumani, late in the December 2009 quarter. The principal rock types observed were weathered banded iron formation, locally referred to as itabirite.
Rock chip assay results from Mipoundi North ranged from 37.9% Fe to 49% Fe. Results for Mbinda and Doumani ranged from 32.3% Fe to 41.5% Fe. Encouraging results were also received from 2 samples to the north of Mbinda being 34% Fe and 42% Fe.
A range of target size models for the magnetic anomalies, constrained by the existing geological information, were developed to assess the best fit with the surveyed magnetic intensity. The principal input variables were width, strike, dip, magnetic susceptibility (SI from 0.5 to 2.0) and depth below surface.
Based on this modeling, exploration target sizes1 were estimated for Mipoundi North, Mbinda and Doumani with a total low estimate of 200 million tonnes and a total high estimate of 300 million tonnes of dominantly itabirite iron mineralisation. When added to the exploration target sizes previously announced for Mt Lekoumou, Mt Mipoundi and Mt Lekoumou South, the revised aggregate exploration target size1 at the Mayoko Iron Ore Project is a range of 0.9 to 1.3 billion tonnes.
Further prospecting including trenching is planned during 2010 at the new targets, and DMC plans to extend the airborne geophysical coverage of the Mayoko licence to the north and south with a regional survey to be undertaken later in 2010.