The traditional association of the later Mesolithic with narrow-blade or geometric microlithic technology has been challenged in recent years by the excavation of several sites along the Forth Littoral such as Cramond, Echline Fields, East Barns and Howick in Northumberland. These have all produced large, well stratified and contextualised assemblages of narrow-blade material dating to the mid to late 9th millennium BC.

The assemblages of the Forth Littoral sites appear to be dominated by scalene microliths, with the exception of Echline Fields where this form was replaced with crescent types. This was also the case across the Forth at Fife Ness, Fife (Wickham-Jones and Dalland 1998) suggesting some possible form of site specialisation. Other tool forms represented included a wide range of other microlith types such as backed bladelets/rods and crescents, numerous small scraper forms, retouched flakes and blades, piercers and in the case of the assemblages at East Barns and Cramond quantities of micro burins and notched pieces. These artefacts were relatively scarce at Howick and Echline Fields, which is possibly due to a lack of surviving in situ working areas at these sites (Engl 2021, 57). The presence of microburins has been closely associated with the production of scalene triangles (Wickham-Jones and McCartan 1990: 100).

All stages of the chaîne opératoire were present within these assemblages with blade and blade/flake forms being the predominant core type. This suggests that blade manufacture was an important focus of activity within the sites of the Forth Littoral. A variety of other core types were present including bipolar examples. At East Barns this was associated not only with the reduction of intractable material but also the curation of exhausted flint platform cores. A wide range of regular blades, flakes and other debitage was present within the assemblages (Engl 2021).
In recent years the excavation of several sites in the Daer Valley (Sites 1–3) situated within the uplands of South Lanarkshire (Ward 2017) have produced a large corpus of lithic material associated with dates ranging from the turn of the 8th millennium BC to the Mesolithic-Neolithic transition. Though much of this material awaits analysis and full publication these three sites define the transition between the Early and Late Mesolithic periods and contain valuable typological evidence (Ballin pers comm).

The scatter sites of the Tweed valley though lacking contextual information appear to provide a similar signature with a variety of microlithic forms, scrapers and rare micro burins. However, the scatter sites are mixed with substantial amounts of later material and in the case of Craigsford Mains possibly earlier material. The assemblages of the Tweed valley, though quantitively significant, require a substantial reappraisal if they are to be an important addition to the archaeological record.
The appearance of narrow-blade lithic industries within South East Scotland has been proposed as a specific cultural response to the inundation of the North Sea Plain at the turn of the 8th millennium BC (Waddington et al 2007; 2015; Waddington and Bonsall 2016; Waddington and Passmore 2012). This builds on Saville’s tentative view that this technological change to narrow-blade assemblages within the British Mesolithic was happening first within northern Britain.