Dipping back in my A-level field notebook and in those pre-digital days, I found that colour prints could be more useful than slides, as I could stick them in my notebook. Here I’ve indicated a fault in the wave-cut platform of Selwicks Bay, Flamborough Head.
Flints in Chalk
Flints are exposed in the chalk of the wave-cut platform south of the fault. Flints like these may have formed when the silica-rich skeletons of sponges and other creatures formed a gel on the seafloor which was drawn down into burrows in the chalk ooze – hence the shape of the nodules.
Buttress of Contorted Chalk
We looked at a buttress of contorted chalk south of the fault. The chalk contorted by the fault has been re-cemented by calcite-rich fluids circulating through the rock and depositing veins of calcite.
Strengthened by this cement the chalk is harder than that surrounding it and it has withstood erosion and formed a buttress.
Contorted Chalk with Calcite Veins
This vein is exposed on the wave-cut platform in front of the buttress.