As I was collecting at Arkona in the Widder Fm yesterday, my eye was drawn to this piece. It had a lot going for it - apparent texture, concentric ribbing, suggestive shape. Not knowing for sure at that moment, and not wanting to spend valuable collecting time deliberating on it when I had a lot of shale to move, I simply put it in the bucket so that I could take a closer look when I got home.
My question for those who know more about taphonomy and such would be this: can anyone tell me a bit more on the processes that produce this kind of nodular form? The concentric patterns are kind of throwing me, almost as though there was some reworking due to tidal turbulence, like mixing dough in a bowl. I'd certainly appreciate learning a bit more about this phenomenon, as it provides me a bit more by way of clues as I move from layer to layer.