M.Chapman 688 Posted June 19 I took this photo of some scratch marks on some rock on Skye. This is a closeup. This is a more general view showing a similar scratched rock in the foreground. I suspect these scratches were caused by glacial action and have captioned an keyworded accordingly. But I would value a second opinion. I think it's quite unusual to see glacial scouring scratches in several directions. I suspect this rock (boulder) was originally inverted and being pushed along a rocky surface by a glacier above. The boulder may have rotated at some point causing the direction of scratches to change. That's my theory anyway... Thanks in advance Mark Share this post Link to post Share on other sites
geogphotos 958 Posted June 19 Have you got 'Striations'? 1 Share this post Link to post Share on other sites
Inchiquin 612 Posted June 19 I think the first pic is a stone-age carving of an electricity pylon. Alan 1 Share this post Link to post Share on other sites
M.Chapman 688 Posted June 20 9 hours ago, geogphotos said: Have you got 'Striations'? No I hadn't, thanks for that Share this post Link to post Share on other sites
Stokie 442 Posted June 20 16 hours ago, geogphotos said: Have you got 'Striations'? If you have, I believe you can get pills to help............. Share this post Link to post Share on other sites
Brian Vickers 13 Posted June 20 Is it fossilised foliage embedded on the surface perhaps? Share this post Link to post Share on other sites
spacecadet 1,925 Posted June 20 1 hour ago, Brian Vickers said: Is it fossilised foliage embedded on the surface perhaps? No. Fossilised leaves look like, well, leaves. Share this post Link to post Share on other sites
Inchiquin 612 Posted June 20 And on the far left of the first picture there's clearly a carving of a monkey wearing sunglasses. Quick, sell the pic to Erich von Däniken. Alan Share this post Link to post Share on other sites
vpics 513 Posted June 20 Personally, I think these scratches look man-made. I took some pics of striated rocks next to a glacier in South America a while ago and the rocks were all striated in the same direction and very smooth. Share this post Link to post Share on other sites
John Mitchell 2,215 Posted June 20 (edited) 18 minutes ago, vpics said: Personally, I think these scratches look man-made. I took some pics of striated rocks next to a glacier in South America a while ago and the rocks were all striated in the same direction and very smooth. I think that striations can go in two (or more) directions -- i.e. they can show two different periods of glaciation. But I'm no geologist. The scratches could also have been made by some sort of digging machine. They do look pretty rough. Erich von Däniken? I thought the aliens must have got him, or perhaps he's working in the White House now. Edited June 20 by John Mitchell Share this post Link to post Share on other sites
aphperspective 39 Posted June 20 55 minutes ago, vpics said: Personally, I think these scratches look man-made. I took some pics of striated rocks next to a glacier in South America a while ago and the rocks were all striated in the same direction and very smooth. I tend to agree the boulder has far to many raised sharp edges, a glacier would have ground it flat and a lot smoother, (saw a lot of those in a past life falling out of glaciers in the Falklands.) Share this post Link to post Share on other sites
M.Chapman 688 Posted June 20 (edited) 1 hour ago, John Mitchell said: The scratches could also have been made by some sort of digging machine. They do look pretty rough. This is a remote location on a Scottish Island so a digging machine is very, very unlikely. Edited June 20 by M.Chapman Share this post Link to post Share on other sites
Michael Ventura 2,674 Posted June 20 Here are some examples from a blog show glacial striations on rock (in Canada). https://blogs.agu.org/mountainbeltway/2014/10/28/glacial-striations/ Share this post Link to post Share on other sites
M.Chapman 688 Posted June 20 1 hour ago, vpics said: Personally, I think these scratches look man-made. I took some pics of striated rocks next to a glacier in South America a while ago and the rocks were all striated in the same direction and very smooth. Yes most of the glacial scouring I've seen has created smoother rocks with all the scratch marks in the same direction. But this is often on harder rock. I believe this rock is softer mudstone. The scratches are not man-made - the location is remote and the scale too large (parallel scratches extending over a metre or so) for simple hand tool scratches. There are also numerous rocks here with similar scratch marks. The heavily glaciated (during the ice age) Cuillin mountain range is nearby where other rocks show the more conventional uni-directional scouring. It's why I photographed them, they look quite unusual. Mark Share this post Link to post Share on other sites
M.Chapman 688 Posted June 20 (edited) Ah-ha, I think I've found what they might be - "drift ice abrasion marks" See article and photos here PS. If the link doesn't work for you, try a different browser. It displays OK for me in Safari, but not Chrome. Mark Edited June 20 by M.Chapman Share this post Link to post Share on other sites
John Mitchell 2,215 Posted June 20 1 hour ago, M.Chapman said: This is a remote location on a Scottish Island so a digging machine is very, very unlikely. Don't you remember this old joke? Q: How was the Grand Canyon formed? A: A Scotsman accidentally dropped a penny down a gopher hole. 1 Share this post Link to post Share on other sites
MDM 743 Posted July 3 On 20/06/2018 at 20:14, M.Chapman said: Ah-ha, I think I've found what they might be - "drift ice abrasion marks" See article and photos here PS. If the link doesn't work for you, try a different browser. It displays OK for me in Safari, but not Chrome. Mark I think you are probably right Mark. I am not an expert on glacial features but the explanation in that paper seems very plausible. 1 Share this post Link to post Share on other sites
M.Chapman 688 Posted July 3 7 hours ago, MDM said: I think you are probably right Mark. I am not an expert on glacial features but the explanation in that paper seems very plausible. Thanks. Mark Share this post Link to post Share on other sites
