Muremera ProjectThe Muremera Nickel Project in Burundi is located a short distance away along strike from Xstrata's Kabanga Nickel Project (which is on the Tanzanian side of the Burundi/Tanzania border), thought to be the single largest undeveloped nickel sulphide deposit in the world. Following the renewal of the Muremera exploration licence in August 2009 and the corresponding renegotiation of the exploration expenditure commitment to approximately US$2 million over two years, Nyota embarked upon a review of all available historical exploration data by an independent consultant specialising in nickel geology. As part of the review, new software was purchased specifically to undertake 3D modelling of the geology based on geological mapping, diamond drill hole log data and geophysical information. In addition, the work programme for Muremera was revised to include a new round of ground and downhole geophysics comprising electromagnetic surveys over the most prospective areas within the licence. In February-March 2010, twelve drill holes from the 2007-2009 drilling programs were surveyed by down-hole electromagnetics (DHEM) by the South African contractor, GSS. After initial processing and interpretation by the contractor, the results were subsequently fully interpreted and reconciled with their respective VTEM targets by Condor Consulting of USA. In general, survey productivity was better than hoped and most of the holes attempted were open for surveying. Only two of the 2008-2009 holes were blocked (including RUJA_D001 containing a 16m intersection of massive sulphides). Three other holes were not attempted as they were of lower priority. However, the DHEM surveys suggested that the use of VTEM surveying (as previously undertaken over the Muremera licence area) was of limited success in differentiating between moderate and very good conductors and that, accordingly, a program of ground electro-magnetic surveys might be more useful in testing prospective mafic-ultramafic bodies for massive to semi-massive sulphide mineralisation that might not have been detected by the VTEM survey. Such a program has been included in the latest work program and budget for the Muremera project. In March 2010, 523 drill core samples were shipped to ALS Chemex for multi-element analysis by fire assay (Pt, Pd and Au) and acid-digest -- ICP-AES (Ni, Cu, Co Cr, Fe, etc). Those samples mainly comprised weakly ultramafic and mafic lithologies with disseminated sulphide from the 2008 and 2009 drill holes in most of the known mafic-ultramafic bodies at Muremera. The focus of the assay program was to establish the range of nickel tenors of the mineralised system in order to enable future exploration work to be prioritised (as only the mafic-ultramafic bodies containing higher-tenor disseminated sulphides are likely to host high-grade massive sulphides). From the assay results, the group of bodies containing a wide range of sulphide tenors (clustered in the Rujungu-Muremera F areas in the northern part of the licence) was separated from the group exhibiting low-tenor sulphides, for future follow-up work. Finally, a newly-interpreted surface geological map was combined with structural measurements and geophysical inversion of the VTEM survey to generate a three-dimensional geological model of the northern part of the licence areas, to a depth of two kilometres. This model shows the main folded structures in three dimensions and confirms the continuity of the host stratigraphy between the Kabanga area in Tanzania and the Muremera area in Burundi. |
