Scotish Regional Metamorphism - Buchan
The Buchan Facies Series of regional metamorphism is characterized by the widespread development of andalusite and cordierite in metapelitic rocks, indicating that the conditions of metamorphism were at lower P than those of the Barrovian Facies Series. Once again, the type locality of Buchan metamorphism is the Dalradian of Scotland.
The Buchan is characterised by the following metamorphic zones:
Biotite Zone (Greenschist Facies)
Cordierite Zone (Amphibolite Facies)
Andalusite Zone (Amphibolite Facies)
Sillimanite Zone (Amphibolite to Granulite Facies)
We will be spending 3 days looking in detail at these classic rocks, examining the classic low-P metamorphic zones and associated assemblages developed in metapelitic and calc-silicate rocks. We will see partially melted rocks (migmatites), meta-gabbros and associated contact metamorphic rocks, amphibolite-facies shear-zones, sedimentary structures and much else.
Perhaps the word’s best-exposed regional isograds occur within the coastal section around Banff.