Kendrick Resources has begun building a geological model and volumetric estimate for its Teufelskuppe rare earth project in Namibia after completing 90 drill holes, moving the project closer to its first JORC-compliant Mineral Resource Estimate.
The London-listed company said on Monday that drilling to date comprises 38 diamond and 52 reverse circulation (RC) holes, while further infill diamond drilling continues across the Teufelskuppe carbonatite complex.
The latest preliminary portable X-ray fluorescence (pXRF) results returned broad zones of light rare earth oxide (LREO) mineralisation, including 20 metres at 5.08% LREO, 23m at 4.85%, 40m at 3.37% and 48m at 3.36%.
Kendrick also reported wider mineralised intervals, including 78m at 2.81% LREO, 48.75m at 2.20%, 43m at 2.55%, 41m at 2.25%, 33m at 2.85%, 32m at 2.84% and 28m at 2.87%.
Higher-grade sections included 6m at 6.98% LREO, 7m at 5.90%, 8m at 5.84%, 4.5m at 5.42%, 7m at 5.38% and 11m at 4.80%. The results are preliminary pXRF measurements, not certified laboratory assays.
The significance of the latest update, however, extends beyond the new drilling results.
Kendrick said it is using the growing drilling database to develop an in-house geological model and establish a framework for a Mineral Resource Estimate. At the same time, the company continues to receive certified laboratory assays.
Detailed logging and sampling of the holes are continuing, with composite samples being submitted for independent certified laboratory analysis. The company said previous comparisons between pXRF measurements and certified assays have given it confidence to use the preliminary data to start modelling the deposit rather than wait for all laboratory results.
The in-house work will include a volumetric estimate of the mineralisation, which will subsequently be updated using certified laboratory assays as Kendrick works towards a Mineral Resource Estimate compliant with the 2012 JORC Code.
Kendrick chairman Colin Bird said the consistency of grades and continuity of mineralisation over substantial widths remained defining features of Teufelskuppe.
“With two drill rigs operating we are expanding our coverage over the multiple sills and dykes that make up the Teufelskuppe carbonatite complex,” Bird said.
He said the pXRF information was providing confidence in the distribution and grade of mineralisation, while incoming certified assays were supporting the data needed to develop the resource estimate.
The latest work represents another step in Kendrick’s attempt to convert Teufelskuppe from an exploration target supported by drilling and surface mineralisation into a formally defined mineral resource.
The company had already identified an estimated 14 million tonnes of above-ground carbonatite mineralisation from exposed outcrops using digital elevation modelling and updated bulk-density information.
That figure is an in-house estimate and is not a JORC-compliant Mineral Resource. Kendrick has been working to verify and incorporate the surface material, together with subsurface drilling, into its resource work.
Earlier drilling indicated that mineralisation extends beneath the exposed carbonatites, prompting Kendrick to expand drilling across the TK1 to TK7 structures.
The company initially focused on diamond drilling but later introduced RC drilling to increase the subsurface information available for resource definition.
Kendrick said earlier in September that it had started verifying its in-house resource work and converting it to JORC 2012 compliance alongside the diamond and RC programmes. The latest 90-hole dataset substantially increases the drilling information available for that process.
The company’s drilling programme was designed to determine the subsurface configuration and dimensions of the carbonatite cone sheets and dykes after earlier work suggested the visible surface carbonatites could represent only part of the mineralised system.
Resource definition is proceeding alongside metallurgical studies aimed at establishing how the rare earth minerals could eventually be recovered.
Kendrick appointed Germany’s Anzaplan in August to undertake early-stage metallurgical assessment and Mineral Liberation Analysis on bulk samples from the project.
Subsequent independent mineralogical work found that more than 95% of the rare earth pool at Teufelskuppe is hosted in minerals that Kendrick says are amenable to established processing routes.
Certified analyses also returned average thorium and uranium concentrations of 144 parts per million and 3.6 ppm, respectively.
The combination of drilling, resource modelling and metallurgical work is intended to provide the technical information required for the next stage of project assessment.
Teufelskuppe forms part of Kendrick’s Bonya rare earth project in Namibia. The company has an agreement with Bonya Exploration (Pty) Ltd under which it gains a 70% interest in the Teufelskuppe and nearby Kieshöhe exploration licences.
