mastodon 4.8.0-nightly.2026-10-06Welsh-Polish grandchild of forced labour survivors of the Nazi regime. The rule of law: all else follows from there. Former microbiologist, now wandering over and inside the mountains, capturing and writing about north Wales' heritage. Fellow, Royal Astronomical Society. I also fly and motorcycle.
Dear geologists: how do I summarise the processes leading to this pattern of colours in a slate bed in north Wales? Ignore the brown stuff on the right, which is just staining/biofilm Credit given in my voluntarily-written account of a drainage adit, which cuts through this. 🙏
#Geology help needed, please!
I'm writing up a visit to a 1903 abortive slate adit in north Wales, where the quarrymen were seeking a life independent of the oppressive Lord Penrhyn. Amongst the debris on the floor was the stone shown below.
If anyone can offer a description of it's geological history, I would like to include this in my write-up, with suitable credit, of course.
The stone's a few cm across.
Crib Goch this lunchtime. Great day for walking.
