1986 Annual report Cosmo Howley - Big Howley

Abstract

R Read and Associates, acting for Regent Mining, had established at early 1986 and in situ proven resource in the East Limb-Nose area of 1.1 Mt at 4.2 grams per tonne comprising 225.1 Kt at 3.4 grams per tonne oxide and 851.3 Kt at 4.4 grams per tonne sulphide material. An additional approximate 75,000 t at 4.0 grams per tonne on the West Limb had also been inferred by R Read. Re-evaluation of the geological mapping and drilling data combined with the test pit results indicated there was some misinterpretation in arriving at the above figures. Newly calculated figures indicate a proven resource of about 927,700 t at 2.39 grams per tonne oxide material which is inclusive of about 321,270 t at 2.22 grams per tonne 'new' ore as delineated by recent November-December drilling. Re-calculations of in-situ reserves for sulphide material has not yet been conducted. However, the shallow holes of the November-December drilling program have defined a further 309,619 t at 2. 92 grams per tonne of 'new' sulphide ore not previously included in R Read's calculations. Oxide ore, not sulphide ore, was the exploration target pursued by Dominion during 1986. In the metallurgical test pits, about 500 samples were collected and assayed. The test pits were mapped at 1:250 scale. Additionally, some 400 samples were collected and assayed from 9 Ditchwitch lines on the southern extension of the east and west limbs. In November-December, a total of 3000.5 m of reverse circulation drilling was completed in 52 holes (average depth 57.7 m) with holes located on southern extensions of both east and west limbs. A further 6 water bore holes were drilled for 327 m (average 54.5 m depth). Assay samples were mostly collected at 1 m intervals over the entire drill hole, producting about 2,678 samples. About 10% of the drill samples were additionally check sampled and despatched to an alternate laboratory.