New Members woodnah Posted June 8, 2020 New Members Share Posted June 8, 2020 Hi everyone. Of all stones I have found, this one puzzles me the most and I don’t know what to think about it. It would be nice to hear from you, even if it would just mean excluding the possibility that it is a fossil. I'm sharing the photos and all the information that might be useful. The place: Mount Medvednica has risen some 10 million years ago, at an area of ex Pannonian sea. The mountain is made of palaeozoic and Mesozoic rocks. There are deposits of limestone and dolomite and various karst phenomena — there is cave explored 6km in depth 5km far, where the Neandertal man was found. There are many finds of shells and fish on the Medvednica (over 3000), and a couple of km further a whole whale skeleton about 13 million years old and 6m long was found (cub, the only specimen found of its kind). I found the rock on the forest floor while mushroom hunting, on a steep side beside a mountain stream, but not in it, on an altitude around 400m. The roots might have brought it up as there were many fallen trees around. The surface is dotted with intersecting lines, some more than 10cm and some only 2mm long. The general shape is triangular, it is flat (6,5-7cm thick) and has indentations on two on two opposite sides. The lines concentrate (more and more tiny dashes closer to the indentation). There is a tiny indentation on the “front” side as well. There are both “engraved” and bulging lines, so the texture is a relief. I have more photos, but this fits into the limit. I can add them if there's any need. I’ll appreciate your comments! Link to comment Share on other sites More sharing options...
BobWill Posted June 8, 2020 Share Posted June 8, 2020 Those marks look a lot like glacial striations or scour marks. 1 Link to comment Share on other sites More sharing options...
westcoast Posted June 8, 2020 Share Posted June 8, 2020 Weathered meshwork of fine mineral veins. 2 Link to comment Share on other sites More sharing options...
supertramp Posted June 8, 2020 Share Posted June 8, 2020 43 minutes ago, westcoast said: Weathered meshwork of fine mineral veins. ...and karst dissolution grooves on microfractures https://books.openedition.org/pub/11165 ciao 3 Link to comment Share on other sites More sharing options...
New Members woodnah Posted June 8, 2020 Author New Members Share Posted June 8, 2020 Thank you all, I'm learning. It looks fantastic and dramatic, the mesh of microfractures, and your explanation sounds perfectly logical. I didn't know about any of this. Thanks! Link to comment Share on other sites More sharing options...
hndmarshall Posted June 10, 2020 Share Posted June 10, 2020 looks like it would make a very nice display piece very interesting Link to comment Share on other sites More sharing options...
jpc Posted June 10, 2020 Share Posted June 10, 2020 cool rock. These other folks have better answers to your actual question. But... cool rock. Link to comment Share on other sites More sharing options...
Pemphix Posted June 10, 2020 Share Posted June 10, 2020 On 8.6.2020 at 4:43 AM, BobWill said: Those marks look a lot like glacial striations or scour marks. +1 for glacial striation https://en.wikipedia.org/wiki/Glacial_striation Link to comment Share on other sites More sharing options...
Mark Kmiecik Posted June 15, 2020 Share Posted June 15, 2020 Too much directional change over a short distance to be glacial striations, IMHO. If the rock was meters in diameter, then possibly. Glaciers don't tend to make abrupt turns. However, I would have collected it as a fine specimen of whatever it is. Mark. Fossil hunting is easy -- they don't run away when you shoot at them! Link to comment Share on other sites More sharing options...
BobWill Posted June 22, 2020 Share Posted June 22, 2020 On 6/15/2020 at 3:17 PM, Mark Kmiecik said: Too much directional change over a short distance to be glacial striations, IMHO. If the rock was meters in diameter, then possibly. Glaciers don't tend to make abrupt turns. However, I would have collected it as a fine specimen of whatever it is. I would think that is correct about glacial movement but I was imagining the rock turning as it was pushed along. Do think these long, straight lines are the result of fracturing instead? Link to comment Share on other sites More sharing options...
Mark Kmiecik Posted June 22, 2020 Share Posted June 22, 2020 4 hours ago, BobWill said: I would think that is correct about glacial movement but I was imagining the rock turning as it was pushed along. Do think these long, straight lines are the result of fracturing instead? Possibly. Or mineral veins? If you follow the length of one of the "striations" it changes direction 180 degrees too frequently. I don't see enough "parallel" lines to convince me. Mark. Fossil hunting is easy -- they don't run away when you shoot at them! Link to comment Share on other sites More sharing options...
ynot Posted June 23, 2020 Share Posted June 23, 2020 Not glacial. Agree with weathered cracks and veins. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Paleome Posted July 10, 2020 Share Posted July 10, 2020 Oooh! I want it to be an artifact, bit would have to agree that these are naturally produced. I have found similar striations in the Wheeler Shale of Utah. Link to comment Share on other sites More sharing options...
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