Sunday, 13 March 2011

Evidence of the awesome forces of plate tectonics on the Cornwall-Lizard geological boundary

The awesome forces of plate tectonics have been all too evident in recent weeks in New Zealand and Japan.  Only today I have received an email from a colleague at Tokyo University, who tells me that his apartment, 250 miles from the epicentre, feels like a 'shaking table' and there are severe jolts taking place every 30 to 60 minutes. I can't imagine how terrifying that must be.

Cornwall has been shaped by the unimaginable forces of tectonic plates, and in an earlier blog posting (The Lizard Peninsula- a geological wonder) I described how the Lizard peninsula, a short drive from Falmouth, was formed around 300 million years ago by the closing of the Rheic Ocean.

Today we walked from Poldhu Cove to Mullion Cove a beautiful stretch of the south coast of Cornwall. The cliffs which flank Poldhu are typical of the Devonian rocks which were laid down in Cornwall around 380 million years ago, but as we walked southwards towards the Lizard it was evident that these rocks had become more and more crushed and buckled by the advancing Gondwana continent, which finally closed the Rheic Ocean and squeezed up the Lizard.

Poldhu Cove
Polurrian Cove marks the geological boundary between Cornwall and the Lizard, the rocks on the north of the cove being Devonian slates, and on the south hornblende schists of the Lizard. The boundary between Cornwall and the Lizard is also evident as one walks across the beach.
Pollurian Cove looking north from the Lizard side to the Cornwall side
Further on we reached Mullion Cove, and the first evidence of the serpentine rocks which characterise the Lizard and form the beautiful Kynance Cove a few miles to the south.
Mullion Cove
More Cornish Walks
More on Cornwall

1 comment:

  1. beautiful pictures, i wish i can go here for a honeymoon :(

    ReplyDelete

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