Strangely, I saw a program on those Irish sites just yesterday spanning from Sligo https://en.wikipedia.org/wiki/County_Sligo#History in the west to Meath https://en.wikipedia.org/wiki/County_Meath#Places_of_interes... in the east which seemed to be implying that the circles represented a religious movement that was pan-European and demonstrably encompassed at least north-western France, Ireland, and northern Scotland. They also divided it in to two periods, an earlier 'earth worship' phase and a later 'sky worship' phase, though much of the interpretation seemed to be pretty close to pure conjecture, they did identify advances in astronomy may have enabled superior navigation leading to technology exchange, seasonal migration, better timed fishing expeditions and wealth from trade. The program also featured a single glyph inside a monolithic grave. Clearly there was some form of pictographic script coming in to use at the time.