A few pics from Titan

[pwhole]

I've found sandstone/gritstone pebbles in the Speedwell system over the last couple of years, and there's related sediment banks too. If the shale margin used to be around the top of Longcliffe rather than the bottom, then I guess it's likely that a lot of cover material got washed in via early swallets before the valley floor lowered to its present level. I guess its also probable that when and where the shale, Cavedale Lava and limestone roughly coincided, there would be some far more aggressive chemistry going on around and underneath it?

I bet there's some wedged in crevices in Winnats Head too, though I've only been once, and was more concerned with getting out in one piece again than collecting pebbles