John Faithfull ππͺπΊπ΄σ §σ ’σ ³σ £σ ΄σ Ώπ§‘βπ»βπΏToday I was given this fabulous rock specimen from the Lewisian Complex in Iona.
We have a grey banded garnet-gneiss on the left side of the image. This banding is truncated by the dark rock on the right, indicating that the dark rock must have been intruded after the banding had formed.
Then both rocks have been heated, and the grey banded rock has partially melted, forming a granitic melt which has then intruded into the dark rock.
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