The above picture was taken during an afternoon visit recently to Hornsea on the Holderness coast. A fine warm day with, thankfully, an off-shore gentle breeze. As soon as she is on the beach Molly is off in a dash-around on the sand and in the shallow water, no more than that, basically a wimp.
The picture shows roughly a square meter of beach where sand and shingle mix, rather than the areas of total shingle or total sandy beach. The pebbles, just in their colours, show the diversity of the rock types from which they originate. It would be fascinating to have a geological reference book (with pictures) and to take such a small area as a case study, identify the various rock types and the consult a geological map/atlas to see where they might have come from. Almost certainly it would transpire that many came from far away – so how did they get here?
A big part of the answer would be glaciation and the most recent, geologically, spate of Ice Ages across the last four million years. The mighty force of slow-moving ice-sheets and glaciers plucked rocks from exposed strata, transported them locked in the ice and then deposited them during the retreat of the ice as climate warmed. So it is quite possible that some of the pebbles were plucked from Scandinavian strata, those of the Lake District or Scotland. Holderness was created by post-glacial deposition so some pebbles may have been moved around by successive glaciations.
Virtually all the pebbles are rounded in outline this resulting from abrasion as they bumped into each other as a result of lower wave action on the sea bed on the sea bed, this over millennia, then to be deposited on the beach at spring tides/storm times.
So many pebbles, so much diversity, so much history – sounds like a metaphor.
(To be continued).