12 Mar 2014

Now this is what I call an erratic...

Runswick beach has its share of erratics - rocks dragged here by glaciers and dumped when they melted, like this piece of Shap granite. So it was interesting to find this in the boulder clay cliffs today...
Number One Field Assistant had at it with a rock hammer; out came an ammonite partially encased in a nodule. It's the first time in all my fossiling life here I've recovered a fossil from the boulder clay. It was a few hundred metres from where I found it to the nearest shale cliffs, and the closest are very fossil-light. I've never found an ammonite this good in them. Assuming it wasn't stuffed into the boulder clay to fool the unwary, I wonder where this was picked up by either the glacier or the boulder-clay. More Jurassic rock must underly the boulder clay, so maybe it was popped out of that as the glacier or clay ground on its way.

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