Cligga Head - Greisen Bordered Veins

The Coast path passes through these two rocks.
Cligga Head shows a fine example of a Sheeted Vein System with dark Greisen borders .
The Granite was intruded about 290 million years ago.
Cracks developed in the Granite , numerous parallel cracks at this location at Cligga Head.
Hot fluid left after the Granite crystallised flowed through the cracks and broke down the feldspar ....., forming quartz and mica ...a process called Greisening.
A second mineralisation in the Greisen deposited Crystals of Quartz , Cassiterite (Tin ore) and Wolframite (tungsten ore) ....
A final mineralisation occured throughout the granite - the Kaolinisation of the feldspars with the outside of the feldspars that remain having a powdery coating
Ref:
1949
Date:
2015-06-30 00:00:00.0
Location:
SW 7389.5370
Photographer:

Cligga Head - Greisen Bordered Veins

The Coast path passes through these two rocks.
Cligga Head shows a fine example of a Sheeted Vein System with dark Greisen borders .
The Granite was intruded about 290 million years ago.
Cracks developed in the Granite , numerous parallel cracks at this location at Cligga Head.
Hot fluid left after the Granite crystallised flowed through the cracks and broke down the feldspar ....., forming quartz and mica ...a process called Greisening.
A second mineralisation in the Greisen deposited Crystals of Quartz , Cassiterite (Tin ore) and Wolframite (tungsten ore) ....
A final mineralisation occured throughout the granite - the Kaolinisation of the feldspars with the outside of the feldspars that remain having a powdery coating
Ref:
1949
Date:
2015-06-30 00:00:00.0
Location:
SW 7389.5370
Photographer: