Northern Earth 135 also has a nice piece on rock art in Scotland's Kilmartin region where there are 133 known panels of rock art in an area nearly 8 square miles. The Lion and Tiger stones are outcrops of hard rock smoothed by glaciation, 492 feet apart – and a decorated menhir stands nearby. Archaeologist Richard Tipping and pals (Stirling University) (see also British Archaeology 126 Oct 2012, see www.britisharchaeology.org/ba126) found that the wider countryside had been open since 4300-4100BC. He didn't make the connection with the continent when at this time there is evidence of widespread landscape fires which appear to have been an incentive for large numbers of farmers to enter the British Isles. Be that as it may, the archaeologists went on to dig right beneath the rock panels and immediately came across fragments of quartz (similar finds were found at rock art sites in Scandinvia) and scatters of quartz occur all over the area together with over a thousand quartz pebbles. Experimenting with the pebbles they found they were capable of engraving the rocks at Kilmartin, but some of them were prone to break up into fragments. Interestingly, when freshly cut the carvings were not the dull grey of today (weathering) but were coloured red and green – colours associated with meteors, aurora, and other atmospheric phenomena. In addition, the remains of a platform of clay and stones was discovered, edged by a straight wall. This was probably where the artists stood to engrave the rock panels.A C14 date derived from a post hole came out at 2500-2300BC, and quartz fragments gave a date of 2900BC (in context). Other carvings on the rock produced a date of 1300-1100BC – and all three of these date sets have a remarkable correspondence with low growth tree events.
So, cup and ring marks were created by using pebbles – a bit like winding a coin into brickwork to create a round depression, an activity enjoyed by idle schoolchildren in school playgrounds.
The biggest surprise was a date of 400-600AD at the top of the platform. This coincides with Mike Baillie's 536-41AD low growth tree ring event. Basically, cup and ring markings, and related engravings, have a distinct connection with such events – which appears to rule out volcanic eruptions.