It has lately been recognised by explorers that subsidiary fault splays developed adjacent to the main Yarlbrinda Shear Zone may be more prospective for hydrothermal gold deposits than the main zone. In an approved PACE Initiative Year 2 drilling project, Southern Gold aimed to test the potential for gold mineralisation to be hosted in these subsidiary splays, and thereby to reinforce the geological conceptual model developed by the South Australian Geological Survey that recognises an arcuate, orogenic gold province in the central Gawler Craton, wrapping around the western and southern margins of the Gawler Range Volcanics Domain. In June 2006 an aircore drilling programme (103 holes for a total of 2395 m) was carried out to explore for Tunkilla - style gold targets in the vicinity of the central-northern Yarlbrinda Shear Zone. The drilling was aimed at magnetic features which appeared to meet the criteria of favourable sites for gold emplacement, notably in relation to the Hiltaba Granite serving as a high heat source, the Yarlbrinda Shear Zone acting as a fluid pathway, and a north-east trending demagnetized fault splay forming a suitable hydrothermal fluid trap site. The PACE drill programme results have shown a degree of cover thickness and type which supports Southern Gold's initial suspicion that the regional calcrete sampling conducted by Equinox Resources in the mid 1990s (using a 1.5 km sample interval, infilled to 50 m x 100 m on 3 grids; highest values 5-10 ppb Au, best result 54 ppb Au) may not have been able to detect with sufficient precision a geochemical gold signature where nearby mineralisation in fact exists. The PACE aircore drillholes encountered a variety of granite, mylonitic granite, granodiorite, diorite, and mafic basement units. The occurrence of mylonite fabric at some of the margins of the magnetic granite bodies helps to support the exploration concept behind the project, i.e. proximal to distal shearing possibly associated with the Yarlbrinda Shear Zone. Only one hole showed visible evidence of quartz veining, over a 2 m wide interval. Overall, the assay results for economical trace elements were low, however, further work is planned which will continue to target geophysical targets in this area, as the recent drilling has confirmed the depth of cover and has highlighted some probable related innaccuracies of past surface geochemical sampling. The best assays obtained from the PACE drillholes were 1 m @ 35ppb Au, 3 m @ 1000 ppm Cu and 3 m @ 11.5 ppm U.