Stanner Rocks is a rounded hill, steep in parts, which lies close to the Wales border with England between Walton and Kington.
Holgate & Knight-Hallowes (1941) suggested a Precambrian origin based on the occurrence of dolerite clasts associated with Longmyndian sediments in a nearby quarry.
In the late 1970s the general acceptance of the theory of plate tectonics resulted in a re-investigation of the Precambrian and Paleozoic igneous rocks of southern Britain.
Thorpe et al. (1984) made the earliest developments by identifying the calc-alkaline nature of many of these exposures and interpreting this evidence as the product of Precambrian subduction.
The Stanner - Hanter Complex was not part of this study, perhaps because of its considerable alteration or possibly owing to the limited range of rock types.