The New England Orogen is interpreted to be a complex tectonic collage of terrains which accreted onto the eastern margin of Australia in the Late Palaeozoic (Flood, 1988). It forms the eastern part of the Palaeozoic – Early Mesozoic Tasman Fold Belt System and is subdivided into three provinces; Yarrol in the north, Gympie in the east and New England in the south (Flood, 1988). The Didcot permit lies within the eastern Gympie Province of the New England Orogen. 

Cranfield (1989, 1994) identified and mapped the rocks on the Maryborough 1:250,000 sheet, identifying three major stratigraphic blocks in the region. These blocks young eastward from the Carboniferous Coastal Block, to the Late Carboniferous Goodnight Block and the Permian Gympie Block. The eastern and western portions of the Mt Shamrock tenement straddle the Goodnight Block and the Coastal Block respectively.

The Goodnight Block comprises the late Carboniferous – Permian Goodnight Beds, a sequence of deep marine siltstones, sandstones and cherts with lenses of mafic volcanics. The sequence has been metamorphosed to mid-greenschist facies during approximately E-W compression, forming schists and phyllites. The deformation produced NNE to NE trending upright folds and thrusts with a strongly developed axial planar schistosity. The Goodnight Beds are intruded by dioritic – granodioritic porphyries and intrusive stocks, with associated volcanism during the late Permian. Intrusive complexes are generally localised at the intersection of NE and NW, to NNW trending faults. These rocks are locally overlain by Triassic volcaniclastics of the Aranbanga volcanics within the Coastal Block.

Within the Didcot permit area, late Permian intrusives include the Chowey Granite, located south of the Gebangle prospect. Other intrusives include the Gebangle porphyritic diorite, and the Mt Shamrock intrusive complex. Other minor porphyry dykes and stocks occur in the area and tend to intrude along NE trending faults or at fault intersections.

Williams (1991) identified two phases of intrusive activity at Didcot. The main phase centred on Mt Ophir, forming an upper unit of andesitic to rhyolitic agglomerates and tuffs, and a lower unit comprising a rhyodacitic porphyry stock. There are widespread ring fractures associated with the complex, which are intruded by rhyolite dykes that often have brecciated margins.  

The area is regarded as highly prospective for Intrusive Related Gold Systems such as Mt Rawdon and porphyry mineralisation such as Coalstoun. It is the contention of the Proprietors of Kangal Resources, that whilst the area has been heavily explored, it has not been effectively explored for this style of mineralisation.