Sunday, 15 November 2015

Solway sojourn - signs of stress


The coastline between Meggerland Point and Borness Point contains some really great geology.  We paddled along past strata which have been folded and contorted into an astonishing variety of shapes and patterns.  Wigtown Bay is one of the better places to view the results of the stresses of the collision between Scotland and England some 460 million years ago.





 Getting right in close at the base of the cliffs reveals that there's two different types of rock layered like plywood, and in this image thrust vertical.

500 million years ago Scotland and England were at opposite sides of the Iapetus Ocean, which lay to the south of the Laurentian supercontinent.  The rocks which would end up exposed here in Wigtown Bay were formed by submarine mudslides interspersed with periods of steady sedimentary accumulation.  The submarine slide process is called "turbidity" and the resulting Silurian grey mudstones layered with red sandstones are described as "alternating turbidite lithofacies" (which is a phrase I must remember!). 

The impact as the islands which would become Scotland and England crunched together  would affect much of Scotland by throwing up alpine-scale mountain ranges in the Caledonian Orogeny.....so we have our southern neighbours to thank for the superb hillwalking we enjoy today!

The point at which the Iapetus Ocean finally disappeared as Scotland and England joined together (the Iapetus Suture) lies just a little to the south of Wigtown Bay, so the effects on the rocks here are pretty dramatic, and made even more so by much later glacial action.





 We explored caves topped by elaborately folded rock......





...and paddled along the bases of colourful cliffs.....





 .....which reached out to steep headlands.





 The relatively soft sandstones and mudstones have been further eroded and altered by relentless wave action as here at Meikle Pinnacle.  We were very fortunate in enjoying calm conditions, a rarity along this coast of strong tides and exposure to the prevailing weather.






 There are "Dove Caves" above the level of the sea.....






...and caves which are submerged at higher states of the tide and lined with colourful anemones.






 Rounding Dunrod Point we paddled towards Brighouse Bay and a last chance to stop before arrival at our intended destination for the evening.





We landed on a tiny wave-cut pebble beach between fangs of rock at the Mull of Ross and found a stone seat on which to sit and survey the stresses which surrounded us.....any resemblance to the three wise monkeys is entirely coincidental.......





The rocks which surrounded us may have been stressed, but we certainly weren't.  We relaxed in the sunshine under a huge Solway skyscape with a view out to the distant Isle of Man.  It seemed that we'd been on our Solway sojourn for quite some time and yet it was still only the first day.  It was, however, late in the afternoon of that day and we still had to make the final distance to our camp for the night.

6 comments:

  1. The resemblance of you all sitting there are rather of three wise, unstressed men, being occupied by being there full time. The timescale is mindboggling. Ta very much for pic's and an enjoyable text, as usual!
    Safe paddling!

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    1. Thanks Leif, thinking about the "deep time" around us called for a bit of a sit down!

      Kind Regards

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  2. Been down in that area walking and rock climbing but viewing it from the water really bring the geology alive.

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    1. It's a great bit of coast Bob - completely different to my expectations of the Solway

      :o)

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  3. Marvellous, Ian, simply marvellous...three "wise men" in mango, I'd say. Warm wishes.

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    1. Thanks Duncan - it's been suggested that we may be more "Three Billy Goats Gruff" !

      :o)

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