M20. Andalusite Hornfels - Clooney, Donegal
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Fact sheet
Description: 

This pelite is from the Neoproterozoic Dalradian Supergroup. It was converted to schist during the ca 470Ma Grampian orogeny, then metamorphosed a second time through contact metamorphism in the aureole of the ca 400Ma Ardara pluton, which is part of the Donegal batholith.  The pluton was emplaced by forceful inflation in two stages.  These two stages may be the cause of the early pink embayed cores (in some porphyroblasts only), and the late clear overgrowth, respectively, of the andalusite.

In Place
In Time
Accuracy:
Timescale:
Not known
Ma = Millions of years ago
In Focus
Type:
Type: 
metamorphic
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