Happy Friday! Here are two more folds in gneisses of the Lewisian, in the North West Highlands of Scotland, near Tarbet.
Enjoy!
Happy Friday! Here are two more folds in gneisses of the Lewisian, in the North West Highlands of Scotland, near Tarbet.
Enjoy!
How can I differentiate between gneiss and migmatite in the field?
There are many different varieties of migmatite. This book delineates them masterfully.
There are injection migmatites and anatectic migmatites – two very different origins! In one, the melt comes from somewhere else, and in the other, it is locally derived through anatexis (partial melting).
In general, what I would look for to spot an anatectic migmatite is segregation of pockets of felsic material (“leucosome”) from residue of mafic material (“melanosome”).
Thank you, Dr. Callan.
Where were the Callanish Standing stone quarried?
How did the earky inhabitants of Lewis Isand quarry and work the Lewisisan gneiss stones?
Thank you
Hi there,
I’m not sure. I haven’t been to the Callanish stones. This blog post isn’t about them, either.
Sorry,
CB