Valentia Island, a set on Flickr.
Our last day - Valentia Island
Friday 20 May 2011
Sunday 1 May 2011
Last day - Tetrapods and myriapods
The final day was all on Valentia Island, now with a handy bridge across from Portmagee. We started off at the old Valentia slate quarry at Dohilla where smooth slabs of astonishing size were produced in the past: used for billiard tables and shelving in particular. These are underground quarries but were closed in 1911 because of foreign competition - from Wales - though there has been some recent interest and we could see modern machinery down in the quarry. Part of the main quarry approach has been converted into a grotto with a statue of Our Lady and Bernadette highup on the cliff. Sadly we didn't know if they were lifesize or no, so no good for scale.
From here we went down to the Tetrapod trackway site, also at Dohilla. This is one of the earliest records in the world of primitive amphibian trackways and was discovered in 1992 by Iwan Stossel, a geology student from Zurich, and published in 1995. Dating of associated volcanic rocks places this at 385 Ma.
The footprints don't show any detail and are likely to be underprints but even so give a lot of information about the size and and movement of the animal. One shows body drag and another, tail drag. They've been deformed by tectonic stress but strain analysis shows the original body length was around 1m.
There's a good interpretation board and the access is easy from the designated car park via a pathway down to the top of the low cliff.
Lunch was in Knights Town - built in the 19th Century for the quarries and, as far as mine went at least, was another bowl of delicious chowder eaten on a roof terrace overlooking the harbour. After a diversion to see the Altazamuth Stone (and some debate about why it isn't Altazimuth) and a walk to the museum to get some booklets about the trackway (if shut ring the number on the door!) we went back round to Trawagwinnaun Bay on the way to Cromwell Lighthouse to check out a wide dolerite dyke, and then below the lighthouse to see the Valentia Slate Fm which has a number of trackways of Diplichnites - must have been about the size of a largish centipede!
As a finale we went over to the other end of the island to Telegraph Field where the transatlantic cables came ashore - a fascinating monument has cross sections of the actual cables embedded and the field is also the site of one of the last dancing platforms.... where comely maidens danced at the crossroad... Bettie and Jan obliged! Cups of tea and scones nearby completed a really super day
With an early start for the 250 mile drive back to Dublin in the morning some of us weren't planning on making a night of it but we still found time to go down to the pub for a last Guinness
From here we went down to the Tetrapod trackway site, also at Dohilla. This is one of the earliest records in the world of primitive amphibian trackways and was discovered in 1992 by Iwan Stossel, a geology student from Zurich, and published in 1995. Dating of associated volcanic rocks places this at 385 Ma.
The footprints don't show any detail and are likely to be underprints but even so give a lot of information about the size and and movement of the animal. One shows body drag and another, tail drag. They've been deformed by tectonic stress but strain analysis shows the original body length was around 1m.
There's a good interpretation board and the access is easy from the designated car park via a pathway down to the top of the low cliff.
Lunch was in Knights Town - built in the 19th Century for the quarries and, as far as mine went at least, was another bowl of delicious chowder eaten on a roof terrace overlooking the harbour. After a diversion to see the Altazamuth Stone (and some debate about why it isn't Altazimuth) and a walk to the museum to get some booklets about the trackway (if shut ring the number on the door!) we went back round to Trawagwinnaun Bay on the way to Cromwell Lighthouse to check out a wide dolerite dyke, and then below the lighthouse to see the Valentia Slate Fm which has a number of trackways of Diplichnites - must have been about the size of a largish centipede!
As a finale we went over to the other end of the island to Telegraph Field where the transatlantic cables came ashore - a fascinating monument has cross sections of the actual cables embedded and the field is also the site of one of the last dancing platforms.... where comely maidens danced at the crossroad... Bettie and Jan obliged! Cups of tea and scones nearby completed a really super day
With an early start for the 250 mile drive back to Dublin in the morning some of us weren't planning on making a night of it but we still found time to go down to the pub for a last Guinness
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