A preliminary geological assessment of Craiglea Quarry, Logiealmond, Perthshire

This report describes the outcomes of a preliminary geological assessment of Craiglea Quarry, Logiealmond, Perthshire [NGR 294950 732290]. The quarry is a source of Highland Border Slate, a building stone that has seen widespread use throughout much of Scotland as a traditional roofing material. The extant worked faces of the quarry expose inter-layered metasandstone (psammite) and metamudstone (pelite) rocks; the latter is a true ‘slate-rock’ and would have been the target of the quarrying activities. The ‘slate-rock’ appears to be bestdeveloped within a 20–30 m thick, inclined layer consisting predominantly of metamudstone. Renewed extraction of slate at the quarry may be challenging due to the degraded state of the former quarry, where abundant screes cover the original workings and limit access. Furthermore, extracting significant quantities of high-quality slate would likely involve removal of a relatively high volume of psammite rock that may end up as waste unless a use for this material (as a ‘by-product’ of the slate quarrying) can be found. Nonetheless, recoverable slate is present and could be targeted by further extending the existing workings to the north-east or east.