Annual report on EL 4816 September 1988

Abstract

A first pass sampling programme was undertaken concurrently with the present mapping project. Initially, samples of as wide a range of lithology, mineralogy and microstructure as possible were sent for analysis in an attempt to determine a host environment for the gold mineralisation in this particular area. Emphasis was then directed to sampling quartz veins and gossans. All samples were rock chips with an average weight between 0.5 and 1 kilogram. A small minority were single specimens, most were 3 to 6 pieces, as homogeneous as possible within a particular rock type, bulked from a small area of a -few metres radius. Soil sampling was not attempted. A total of 59 samples were submitted -for analysis, collected from within (and a few just outside) the tenement area. Sample locations are plotted. All specimens submitted for analysis were assayed for gold by fire assay, and for As, Ag, Pb, Cu by A.A.S. Gold values in ppm are also plotted, and appended. Sampling practices which evolved for location of anomalous areas during first pass sampling in the McKinlay tenements area involved rejections of certain lithologies or styles of mineralisation which consistently (within the limited number of specimens submitted in the time available) returned negligible gold values. Clear un-mineralised vein quartz always returned low gold values. Metasediments with a network of small quartz veins returned low gold values. Metasediments showing obvious effects of ionic migration returned low grade values (eg. purple sandstone, sometimes with limonite pseudomorphs after pyrite, irrefularly bleached to buff, with small ferruginous quartz veins leaking iron into selvidges). This is a style of mineralisation which 'carries grade' in some other areas but apparently not here, at least at surface. Drilling, at a later stage in the exploration programme, could possibly identify here, as elsewhere, a zone of surface depletion. Gossanous material generally returned good values, but not always. There are two types of gossan in the McKinlay area; a very heavy gossan with galena boxworks (as at McKiniay, Flora Belle, and three other newly identified locations and a light gossan, less well developed, less intensely ferruginised and more quartzitic (as at the Elizabeth mine and the Eliza project). In the later stages of the sampling programme, two areas which showed anomalous gold values were resampled to improve the statistical value of the sample set, to get a better idea of the outcrop extent of the mineralised area, to check the structural controls on mineralisation in the immediate vicinity and thus to confirm that further exploration and systematic second pass sampling was warranted in these areas. In both of these areas the extra samples collected were mainly gossanous (this lithology being the one which 'carried grade' in the first instance), to try to improve the variance, and recheck the gold bearing environment at that location. The two areas of gold anomalism are outlined. The Su Ah Ray Prospect is situated immediately west of the old McKinlay silver-lead workings. Quartz veining in psammites occurs over a strike length of 700 metres and width of 50 metres on the southwest limb of the regional F3 anticlinal structure at the intersection of north-south and 120 striking faults. A total of 22 rock chip samples were collected from over the area. The Zappo Prospect is located 3 km south ofthe Mt Wells Battery Road/Springhill Road Junction. Quartz veining associated with gossans and ferruginous quartz breccia occurs within intervedded psammites and pelites over a strike length of 1.5 km arid widths up to 50 metres. This area is located over an anticline cut by N-S faults. A collection of 25 samples produced values ranging from 0.03 g/t to 4.760/t Au. Further evaluation of these and at least one other area is recommended.