Gold exploration undertaken at Mongolata by CRA has consisted of underground mapping and sampling at the principal workings, viz. the Byles mine and the Golden Harp mine, plus the drilling of 7 vertical exploratory diamond holes (aggregate total depth 288 m) and 1 inclined diamond hole of 201.5 m length to test the un-mined zone between the two mines, the drilling of 1 rotary hole to 92 m in the down-faulted Tertiary sedimentary sub-basin lying east of the Mongolata escarpment, to test the potential for alluvial deep leads, and the drilling of 1 percussion hole to 152 m adjacent to the old water bore near the Byles mine. Gold mineralisation within the oxide zone at Mongolata is seen to occur within iron/manganese oxide - carbonate - quartz veins and breccia zones hosted by a boldly outcropping Adelaidean quartzite and underlying siltstone. Vein orientation is variable, and vein widths are commonly around 0.3-0.5 m. Some veins are stratabound, but others (of significant thickness, e.g. up to 1.6 m) are transgressive. Of the latter, some are flat-lying to gently dipping, others are steeply dipping with variable strike. Breccia zones also vary in orientation and thickness. Some breccia zones are conformable (ostensibly the majority), while others disrupt bedding. Gold distribution appears to be patchy. The gold mined to date is typically very coarse-grained (+80 mesh), occurring as small pockets of spectacularly high grade surrounded by virtually barren rock. Remobilisation within the oxide zone has clearly been extensive. The underground examination of Byles mine disclosed indications of a relatively wider and higher-grade lode just above the water table (a weighted mean assay of 1 of 2 samples taken being 8.2 g/tonne). However, in general no significant gold values were returned from either the underground sampling or the drilling, and the drill core sample assays (maximum 1.84 ppm from surface to 0.79 m in hole 81MOD2) are much lower than (battery) recorded mine grade. It was concluded that drilling provides samples which are much too small to be considered representative. Bulk sampling of veins / breccia in possible mineralised units is the only method available which could be used to adequately test the prospect, but this process is regarded as being too expensive, in view of the very low grade assay results so far returned by the work completed.