Greisen Bordered Veins - Cligga Head (S9)

Cligga Head shows a fine example of a Sheeted Vein System with dark Greisen borders .
The Granite was intrude 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.
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Cligga Head is to the south of Perranporth in Gallery / Section 9
Ref:
1948
Date:
2015-06-30 00:00:00.0
Location:
SW 7389.5370
Photographer:

Greisen Bordered Veins - Cligga Head (S9)

Cligga Head shows a fine example of a Sheeted Vein System with dark Greisen borders .
The Granite was intrude 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.
------------------------------------------
Cligga Head is to the south of Perranporth in Gallery / Section 9
Ref:
1948
Date:
2015-06-30 00:00:00.0
Location:
SW 7389.5370
Photographer: