Annual report on EL 2351 Bridge Creek

Abstract

Owing to the close proximity of adjoining exploration licenses priority was given to delineating the exploration license boundaries on the ground. This was achieved with the aid of the National Mapping 1:100,000 topographic map of the area and aerial photography. Using as many reference and check points as possible with associated measurements, the exploration license boundaries were plotted from the topographic map onto the aerial photograph. From the photographs the north western corner of the exploration license was located on the ground and the western boundary, marked at 100 metre intervals with wooden pegs, was surveyed with the aid of a toperfil chain and prismatic compass. To ensure accuracy further checks were made and it is interesting to note the track shown on the current National Mapping 1:100,000 topographic series, where it passes close to the south western corner of EL 2351, is not the alignment of the new 'Stuart Highway but was in fact an access track used for surveying the current Highway. Using the western boundary of the exploration license as a base line the area covering the old Chinese workings and battery site was mapped at a scale of 1:2000. Additionally, a map at aerial photograph scale was produced to cover EL 2351 and environs. Territory Mining Pty. Ltd., the operators, after consultation with the Department of Mines & Energy, Darwin, dug 5 pits, numbered 1 to 5, within EL 2351. These pits were dug with a 'Hy Mack' excavator as close to bedrock as possible, the depth varying but usually in the proximity of 2 metres. These pits were channel and bottom sampled then panned off in the nearby Bridge Creek. The results from this exercise, while giving some encouragement, were inconclusive, mainly owing to the inability of the excavator in some cases to dig to bedrock and because it was felt bulk sampling was needed to give a true representation of the gold values. At this point of time Greenex, a division of Greenbushes Tin Ltd., indicated interest in undertaking such an exercise as they had the necessary equipment available in the Northern Territory. As a result of this, in September/October 1981, Greenex established a camp and sampling site on a waterhole of Bridge Creek, by the North Australia Railway Line approximately 3 kilometers to the north of the old workings. Their attached report outlines the programme they undertook and gives the results obtained.