Great Geology Lunch Spots - No. 1: P-Forms near Knock

Had a bit of time at lunchtime today so I headed off to one of my favourite places - the side of Loch Na Keal, just south of Knock near Scarisdale Point. Its a great viewpoint with good views up and down the loch, but importantly, it is reckoned to be one of the best places in the UK to see glacial P-forms. there is a good JNCC paper on these things with various ideas given as to their formation. You can read it at:

http://jncc.defra.gov.uk/pdf/gcrdb/GCRsiteaccount1438.pdf

They also look neat under heavy frost - there are obvious striae on the  P-Forms and these show up well under frost..

As well as P-forms there are also some rather impressive dykes of the Mull Swarm cutting the shore. There is a huge concentration of these things in this area (similar to Croggan in this repsect) and they are very easy to see as all this geology is right by the road!  A few pics, mainly of the P-Forms:


 A particularly wind blown tree is a good location indicator - behind it is a weathered out dyke

Below are some pictures of the P-Forms, most of these run approximately E -W, which is the direction of the ice flow that carved them out.







the picture above is of one of the dykes that cuts the Palaeogene lavas that make up the shore here. It winds a sinuous path across the rocks. It has also been cored in several places, presumably for palaeomagnetic research.



So there you have it, right beside the road, one of the best locations in the country for seeing these features.
And a great place to stop for lunch!

Comments

Post a Comment

Popular posts from this blog

Into the caldera

Image
Weather today was pretty wild and wintry   a day for staying down low! Took a walk along the track beside Loch Ba as far as Glen Clachaig - there is some great mountain scenery in the area and of course it is the location for the world famous Loch Ba Ring dyke. I wanted to have a look at the hills with a bit of snow on them as it often brings out detail that is hard to see otherwise. The pictures below give an idea. Click on the images to see them larger! The Loch Ba Ring Dyke (LBRD) follows the wintry skyline. Seen from near Gruline Moving on to the track by the loch, the weather started to clear but was still quite wild: View up the loch! Moving on this prominent hill is on the RHS: The LBRD runs through this un-named hill down to the loch side. The exposed rock sene at the top is the felsite with basic inclusions that makes up most of the dyke. There are also some noticeable parallel gullies running across the hill. I havent been to investigate these, but t
Read more

North Mull Mesozoic Rocks (3) North of Ardnacross

Image
On the BGS map North Mull and Ardnamurchan, there are a couple of small outcrops of Mesozoic strata just south of Tobermory and north of Ardnacross Farm. These are the rocks that underlie the volcanics. The volcanics are of Palaeocene age ( approx 60 million years old) but the underlying Mesozoic rocks, depending on exactly what they are can be from about 248 million years ago up to 65 million years. So depending on what they are, they could be considerably older Rocks of this type probably underlie most of Mull but it is only in certain coastal locations (and also as xenoliths and in volcanic vents) that we can readily see them. This particular outcrop had intrigued me for a while and it was long overdue a visit. Many thanks to Rory Forrester of Ardnacross Farm for letting me explore at leisure! The view down the sound of Mull is great: The Sound of Mull looks quite wide at this point. Ben Talla has snow on top as do the hills above Craignure Its not just the geology -
Read more

Lighthouse Path Walk 19 Nov 2017

Image
Took a stroll along the newly repaired Lighthouse path that goes to Rubha nan Gall. Great views over to Morvern, up Loch Sunart and over to Kilchoan. I wanted to have a look at the geology esp since if there had been some digging going on during the path upgrade, then there might be some goodies to see.  Here in pictures is what you can see on the path. Of historic interest, this is the location where Prof Heddle discovered the mineral Tobermorite. The new gate on the path A bit further on, there are some neat dykes on the shore at Rubha na Leip: The smaller of the 2 dykes, about 0.5m across The larger of the dykes - about 3m in width and showing very pronounced columnar jointing.Both dykes run NW-SE - Classic "Mull Swarm" stuff. Further along the path there are some interesting amygdales to be seen in the cliff face above the path. Some of the rock here has been recently excavated so is quite fresh. 50p for scale. It was in amygdales that Prof
Read more