Second annual report, EL 1324 Hale River

Abstract

The Exploration Programme undertaken within EL 1324 during the second 12 months of tenure was concentrated on the Albarta and near-by prospects. No field work was undertaken between December, 1977 when the originally planned drilling programme was cancelled and March, 1978 when access and the Albarta Camp were re-established. Drilling commenced on April 20, and was completed in late May. Following the completion of drilling, the Alberta grid was extended, mainly to the south, to cover the extensions of the main fault system and the H-41 airborne radiometric anomaly. Detailed spectrometer and rock chip sampling surveys, and some additional geological mapping were undertaken to further evaluate the uranium potential of the area. Geological personnel conducting the programme were Esso staff geologist P. Symons and contract geologist M. Roche. Fourteen inclined percussion drill holes were drilled into the main Albarta fault system. These holes were designed to test at depth the surface indications of vein-type uranium mineralization and to clarify the structural and lithological controls for this mineralization. An additional 80 metres inclined hole was drilled into the vicinity of the H-41 anomaly to test out-cropping autunite mineralization in sheared leucogranites at depth. All holes were drilled by a Schramm T64H-B rig operated by WL Sides and Son. Holes re sampled at 1m intervals, selected samples were also analysed (atomic absorption technique) for Cu, Pb, Zn, Ag, Ni, and Co. Holes were radiometrically logged with Esso's Mt Sopris 2500 total count system. The drilling programme confirmed that the westerly dipping Albarta fault zone consists mainly of quartz and silicified country rock with minor pyritic chlorite schist, massive chlorite;haematite, and pyrite. The lithologies in the faults hanging wall comprise pyritic chlorite schists and K-feldspar-chlorite-muscovite schists and gneisses. The majority of the radiometric activity is associated with the pyritic chlorite schists and the K-feldspar-chlorite schists, with the fault zone usually being radiometrically inactive. The hole in the H-41 area intersected 80m of schistose quartz - K-feldspar-muscovite (4 tourmaline, magnetite) granitic rocks. Visible autunite mineralization was noted along fracture plans over most of the 0-73m interval. Iron stained clay minerals pyrite are associated with the autunite. The U3O8 geochemical values were found to be consistently significantly lower than the corresponding U3O8 equivalent values interpreted from the radiometric logs. It is possible that the geochemical data may considerably underestimate the true U3O8 content due to the following drilling related inadequacies in the sampling technique: a) Significant losses of fine material occurred during dry drilling due to air suction removing fines from the sample hopper; b) During wet or water injection drilling sample return decreased significantly, losses increasing with drilling depth.