Rock 365 : Day 261 : Gabbro Pegmatite Cairn

20100918

Day 261 : Back home, and here is a small cairn of pegmatititc gabbro cobbles from the back garden collection.  They derive from the St David's Head intrusion but due to weathering on St David's Head itself, the gabbro is not that is not well exposed (See Day 250).  However, the well rounded blocks at Porthmelgan beach show the structures well.  A detailed close-up will be shown on Day 262.

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~ by hypocentre on September 19, 2010.

 
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