vicky77 Posted December 17, 2018 Share Posted December 17, 2018 Hi everyone. I am completely inexperienced in this. I dont even know if I have actually found a fossil. I live in the Karoo and found the attached rocks on one of my mountain climbs. There seems to be a layer of this rock about halfway up and I am sure there are plenty more. If you can advise me. I apologise for the quality of the pictures and hope you can make them out. Thank you so much Link to comment Share on other sites More sharing options...
TqB Posted December 17, 2018 Share Posted December 17, 2018 Hi and welcome to the forum. They look like fracture patterns in basalt or similar igneous rock. Like this, from this site: https://www.sandatlas.org/basalt/ 5 Tarquin Link to comment Share on other sites More sharing options...
Rockwood Posted December 17, 2018 Share Posted December 17, 2018 I agree with the fracture concept, but weathering, specifically the expansion caused by hydration, I believe can play a role in the shape being created in sedimentary rocks as well. 2 Link to comment Share on other sites More sharing options...
Anomotodon Posted December 17, 2018 Share Posted December 17, 2018 Not denying the geological possibility, but look at the similarity of these objects to Ediacaran Cyclomedusa (very very old and very weird and poorly understood creatures). Looks like there are Ediacaran deposits in South Africa. 2 The Tooth Fairy Link to comment Share on other sites More sharing options...
Oxytropidoceras Posted December 17, 2018 Share Posted December 17, 2018 Looks like spheroidal weathering. Go see: 1. Spheroidal weathering https://en.wikipedia.org/wiki/Spheroidal_weathering and 2. Liesegang rings (geology) https://en.wikipedia.org/wiki/Liesegang_rings_(geology) Yours, Paul H. 5 Link to comment Share on other sites More sharing options...
Fossildude19 Posted December 17, 2018 Share Posted December 17, 2018 @Anomotodon I think the Karoo beds are Triassic. That would rule out anything Ediacaran. 4 Tim - VETERAN SHALE SPLITTER VFOTM - APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
doushantuo Posted December 17, 2018 Share Posted December 17, 2018 beidelitic smectite rings in weathered basalt? (in essence thus concurring with Paul H) NB:The Karoo is extensive,also in a stratigraphical sense The Dwyka Beds are certainly Permian 1 Link to comment Share on other sites More sharing options...
Rockwood Posted December 17, 2018 Share Posted December 17, 2018 7 minutes ago, doushantuo said: weathered Key word to explain the difference in appearance between example and post I assume ? Link to comment Share on other sites More sharing options...
doushantuo Posted December 17, 2018 Share Posted December 17, 2018 Yes. Liesegang processes do take place in weathered paleosols Link to comment Share on other sites More sharing options...
ynot Posted December 17, 2018 Share Posted December 17, 2018 42 minutes ago, doushantuo said: Liesegang processes do take place in weathered I agree with the weathered Liesegang processes. However, the rock looks more like a sandstone than basalt. 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...
abyssunder Posted December 17, 2018 Share Posted December 17, 2018 9 hours ago, vicky77 said: There seems to be a layer of this rock about halfway up and I am sure there are plenty more. Could you take some in-situ photos of that layer? " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Herb Posted December 17, 2018 Share Posted December 17, 2018 not seeing any fossils, sorry "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted December 17, 2018 Share Posted December 17, 2018 7 hours ago, Anomotodon said: Not denying the geological possibility, but look at the similarity of these objects to Ediacaran Cyclomedusa (very very old and very weird and poorly understood creatures). Looks like there are Ediacaran deposits in South Africa. I think many of these are now considered to be holdfast marks of rangeomorphs such as Charnia, it's base being called Charniodiscus. Here is one very similar to the photo here, from my collection, Medusina mawsoni, also once thought to be a jellyfish, hence the name. 2 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Rockwood Posted December 17, 2018 Share Posted December 17, 2018 Here's an example of the whole thing from Mistaken Point. 1 Link to comment Share on other sites More sharing options...
ynot Posted December 18, 2018 Share Posted December 18, 2018 15 hours ago, vicky77 said: I live in the Karoo and found the attached rocks on one of my mountain climbs. I think We need to have a better understanding of the age of the rocks You are looking at. Can You look at a geologic map of the area or give Us a location? 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...
vicky77 Posted December 18, 2018 Author Share Posted December 18, 2018 On Monday, December 17, 2018 at 6:43 PM, ynot said: I think We need to have a better understanding of the age of the rocks You are looking at. Can You look at a geologic map of the area or give Us a location? Thank you for your response. I have attached the GPS coordinates to our property. The mountains are south of the property. It is extremely remote. Link to comment Share on other sites More sharing options...
vicky77 Posted December 18, 2018 Author Share Posted December 18, 2018 On Monday, December 17, 2018 at 12:53 PM, Tidgy's Dad said: I think many of these are now considered to be holdfast marks of rangeomorphs such as Charnia, it's base being called Charniodiscus. Here is one very similar to the photo here, from my collection, Medusina mawsoni, also once thought to be a jellyfish, hence the name. Those are very impressive and I see that my one does seem to have a resemblance to these Link to comment Share on other sites More sharing options...
vicky77 Posted December 18, 2018 Author Share Posted December 18, 2018 On Monday, December 17, 2018 at 12:21 PM, abyssunder said: Could you take some in-situ photos of that layer? Thank you for your response. I am currently not on the farm but will send a photo as soon as I return. I have attached a photo of a similar layer in another mountain in the group. The one where I found the rocks was much narrower. Link to comment Share on other sites More sharing options...
vicky77 Posted December 18, 2018 Author Share Posted December 18, 2018 On Monday, December 17, 2018 at 5:12 AM, Oxytropidoceras said: Looks like spheroidal weathering. Go see: 1. Spheroidal weathering https://en.wikipedia.org/wiki/Spheroidal_weathering and 2. Liesegang rings (geology) https://en.wikipedia.org/wiki/Liesegang_rings_(geology) Yours, Paul H. Thank you very much for the links. There are a lot of examples of spheroidal weathering on the mountain itself and a hill in the vicinity. Link to comment Share on other sites More sharing options...
vicky77 Posted December 18, 2018 Author Share Posted December 18, 2018 On Monday, December 17, 2018 at 3:13 AM, TqB said: Hi and welcome to the forum. They look like fracture patterns in basalt or similar igneous rock. Like this, from this site: https://www.sandatlas.org/basalt/ Thank you so much for your links. While there are different kinds of basalt rocks on the mountain in different sections. One section even has what looks like a waterfall of basalt rock running down most of that section. The rocks i have posted are more sand stone than basalt. The links were exceptionally helpful as I was able to identify some of the interesting rocks that I have collected during my explorations. 1 Link to comment Share on other sites More sharing options...
ynot Posted December 18, 2018 Share Posted December 18, 2018 It looks like in that area there is sedimentary rock of the correct age for the suggestions made by Anomotodon and Tiggy's Dad. 1 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...
abyssunder Posted December 18, 2018 Share Posted December 18, 2018 1 hour ago, vicky77 said: Thank you for your response. I am currently not on the farm but will send a photo as soon as I return. I have attached a photo of a similar layer in another mountain in the group. The one where I found the rocks was much narrower. Thank you for the photo. Now I know why you like climbing. The Maine Karoo Basin has a sedimentary character. It is an infill basin. The sandstone succession in the Karoo Basin was accumulated between the late Carboniferous and the early Jurassic, attaining a maximum thickness of 12Km. The uppermost deposits are the youngest in geological time. There's a lot of mudstone and sandstone forming beautiful landscapes with interesting features, like rock doughnuts, pothole structures, polygonal "boxwork" structures, convex polygonal structures, cavernous weathering/erosion forms, slope forms, cliffs, pillars, lichen-cyanobacteria-fungi-induced weathering, etc. There might be a Paradise for the tourists. 3 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Oxytropidoceras Posted December 19, 2018 Share Posted December 19, 2018 There are a number of PDF files of publications on the Internet about the Karoo Basin. Some include; Johann Neveling, Robert A. Gastaldo, and John W. Geissman Permian–Triassic boundary, Karoo Basin, South Africa 35th International Geological Congress Field Trip Guide https://pdfs.semanticscholar.org/8f62/89e59a0b51d1bcef320255e11ed702582302.pdf http://personal.colby.edu/~ragastal/RAG_reprints/RAG2016c.pdf Retallack, G.J., Smith, R.M. and Ward, P.D., 2003. Vertebrate extinction across Permian–Triassic boundary in Karoo Basin, South Africa. GSA Bulletin, 115(9), pp.1133-1152. https://cpb-us-e1.wpmucdn.com/blogs.uoregon.edu/dist/d/3735/files/2013/07/karoopt_final-2hzot5q.pdf https://web.colby.edu/ragastal/publications/ptb-karoo-basin/ Gastaldo, R.A., Adendorff, R., Bamford, M., Labandeira, C.C., Neveling, J. and Sims, H., 2005. Taphonomic trends of macrofloral assemblages across the Permian–Triassic boundary, Karoo Basin, South Africa. Palaios, 20(5), pp.479-497. https://repository.si.edu/bitstream/handle/10088/5946/Palaios_2005.pdf https://web.colby.edu/ragastal/publications/ptb-karoo-basin/ Götz, A.E., Ruckwied, K. and Wheeler, A., 2018. Marine flooding surfaces recorded in Permian black shales and coal deposits of the Main Karoo Basin (South Africa): implications for basin dynamics and cross-basin correlation. International Journal of Coal Geology, 190, pp.178-190. https://researchportal.port.ac.uk/portal/files/8045697/Marine_flooding_surfaces_recorded.pdf There is also a new book, "Origin and Evolution of the Cape Mountains and Karoo Basin." Yours, Paul H. 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now