Abstract
The large sorted stone-stripes of the Rhinog Mountains, North Wales post-date the last major glaciation of this area which occurred penecontemporaneously with the Main Würm glaciation of Continental Europe. Ice from the northern Irish Sea basin, Scotland and the English Lake District, however, readvanced to a position some 25 km NW of the Rhinog Mountains sometime after 16,830 years B.P. The sorted stone-stripes of the Rhinog Mountains and other periglacial fossil forms, developed in the Main Würm glacial drifts of the Cardigan Bay lowlands, were most probably formed during the latter readvance. Their formation, however, was not associated with large scale solifluction.