TSXV-listed exploration company Mkango Resources has identified high grade uranium, niobium and tantalum values at the Thambani project in southern Malawi.
Thambani is primarily focused on zones of anomalous uranium and associated niobium and tantalum targets across the Thambani Massif, a nepheline-bearing syenite gneiss which dominates the north eastern part of the license.
Mkango has completed a trenching program across the Thambani Massif primarily focused on two sites of historical uranium exploration, known as the Chikoleka and Little Ngona targets. An initial set of 9 trenches, selected on the basis of anomalous ground radiometric results, have been re-examined and geochemically sampled across profiles from soil/overburden into bedrock.
The first set of assay results of 142 soil and rock chip samples returned variably anomalous U, Nb and Ta values in most trenches, ranging up to 4.70 % U3O8, 3.25 % Nb2O5 in soil and up to 0.42 % U3O8, 0.78 % Nb2O5 and 972 ppm Ta2O5 in rock chips, notably higher than results from the 2013 reconnaissance surface geochemical sampling program. Results associated with the 10 best U3O8 assays are summarized in Table 1.
Preliminary mineralogical studies carried out on six rock samples from the Little Ngona River and Chikoleka targets, using Scanning Electron Microscopy (“SEM”) at the Natural History Museum (NHM) London, indicate that pyrochlore group minerals, mainly betafite, are the principal carriers of U, Nb and Ta for these samples. Further mineralogical evaluation involving QEMSCANTM analysis is planned at Camborne School of Mines, UK.
Mkango’s exploration activities to date include acquisition of Landsat7 and ASTER satellite imagery for the license area, systematic ground radiometric surveys to confirm and detail previously-known airborne anomalies, reconnaissance geological mapping and litho-geochemical sampling programs. The work has identified a number of potential uranium and associated Nb-Ta targets over the Thambani Massif, which is mainly composed of nepheline-bearing syenite gneiss, forming two prominent ridges known as Thambani East Ridge and West Ridge.
The systematic ground radiometric survey completed by Mkango previously revealed two distinct uranium anomalies occurring across the Thambani East and West Ridges: A strong uranium anomaly, measuring approximately 3 km by 1.5 km, occurs along the length of the Thambani East ridge, with a north-south trend, and a second uranium anomaly, measuring approximately 1.5 km by 0.4 km, occurring on the West Ridge along the western contact of the nepheline-bearing syenite body with the biotite-hornblende gneisses.
Sample preparation and analytical work for the trenching program is being provided by Intertek-Genalysis Laboratories (Johannesburg, South Africa and Perth, Australia) employing ICP-MS techniques suitable for the analysis of uranium, niobium and tantalum. Internal Laboratory QAQC was also completed to include blanks, standards and duplicates.