Explosion Breccia - Trelavour Downs (#213)
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Fact sheet
Description: 

This breccia comes from Trelavour Downs, St Austell, Cornwall. It was transformed from its original granite composition to this brecciated tourmaline-quartz rock by hydraulic pressure and high temperature fluids rich in boron and fluorine that passed through the rock.

In thin section the rock is formed of angular fragments that are veined and broken. One fragment displays fine banding displaced by the brecciation, and another contains larger magmatic tourmaline grains that appear to have been altered. The rock is almost entirely formed of two minerals, tourmaline and quartz.

In Place
In Time
Location description: 
Trelavour Downs, St Austell, Cornwall
Accuracy:
Timescale:
Timescale: 
Permian
Ma = Millions of years ago
In Focus
Collection:
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Type:
Type: 
igneous
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Rock-forming minerals:

Rock forming mineral:

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