1957 Report for operations in NT for April, May & June 1957 and report on reconnaissance of Cambrian area

Abstract

Hot, humid conditions persisted throughout the north but there's been very little rain. The ground is rapidly drying out although many of the flats are still boggy and too green to burn-off. However it should be possible to travel with little difficulty to all of that area held by Authority to Prospect, in two or three weeks time. Work was again restricted at the Hidden Valley area where a bulldozer has been digging costeans. At the end of the month G.W. Patterson made a trip down the coast to the southwest of Darwin to investigate a possible bauxite occurrence between Darwin and Port Keats. Details of the prospecting work carried out are as follows;1. Hidden Valley - The D4 bulldozer completed the costeaning programme at Hidden Valley on 3rd May. In all 34 costeans were dug in nine localities, total length being approximately 3500', with an average depth of 4'. While most of this work was done satisfactorily it was obvious that the machine was underpowered and not capable of digging efficiently in rocky or dry clayey ground. The area in which the costeaning was done is shown on an accompanying plan (No NT 21). In all of these places lead mineralisation had been exposed in the vicinity of old workings or was detected in rubbly - outcropped sandstone and siltstone by KI method. The result of work done at each locality is described in the hardcopy of the company report. 2. Area A - This arera is situated 1 mile SW of Crocodile billabong and has been described in previous reports. Mineralisation has been exposed in 3 of the 5 costeans (Nos. 2, 3 and 4) over a length of about 100' with a maximum width of 72' in costean No 3 averaging 5.6% Pb. Assays from costeans Nos. 2 and 4 have now been received and the results being as follows; In costean No. 4 from 25' to 30' from the western end assayed at 1.6% Pb, 0.53% Ag /ton and the section from 22' - 27' assays at 0.9% Pb. All other samples only contained trace amounts of Pb. Trace amounts of lead were detected in a narrow gossanous occupying a fracture in costean No. 6. There was no mineralisation in costean No. 7.