This is the Hawk's Neb formation on the southern end of Bute. Different layers in the sandstone are very clear.
Close up, some of the layers are reddish and some are almost white. I had heard of there being a calcite-type stone called "cornstone" and wondered whether it could be that.
Close up, the white shows that is probably just an over-abundance of quartz grains. Maybe this was an era when a lot of quartzite Dalradian hills eroded. But quartz means it isn't cornstone.
The red sandstone is clearly more granular. The grains look angular which I think might mean laid down in water. I need to find Penrith sandstone to see what air-blown grains look like.
