n8state Posted May 11, 2019 Share Posted May 11, 2019 I’m a complete beginner so please forgive my ignorance. I found this on my second time deliberately looking for fossils. Honestly, I’ve no idea if it’s a fossil. I did find some other interesting things too but nothing like this. I’ve researched Penarth and it’s suggested that the formation is early Blue Lias? Or Lias Group and dates to Jurassic period. This was found towards the bottom of a cliff and I do not believe it’s been submerged by the sea. Thanks in advance for any pointers, Nathan Link to post Share on other sites
JohnBrewer Posted May 11, 2019 Share Posted May 11, 2019 Not really sure, Nathan but I think you have something there. I expect @TqB will know Link to post Share on other sites
TqB Posted May 11, 2019 Share Posted May 11, 2019 Something mineralogical I think, it looks superficial - perhaps gypsum crust? Link to post Share on other sites
n8state Posted May 11, 2019 Author Share Posted May 11, 2019 Thanks @JohnBrewer and @TqB. Now I’ve looked up Gypsum Crust, certainly looks similar. The texture of the bits in the middle vs the rest of the light grey area is different, much more rough but not sure if that’s just a difference in erosion? What caught my eye was the distinctive shape and that the bit above looks similar and of a similar orientation. Either way I think I’ll hold onto it Link to post Share on other sites
Mark Kmiecik Posted May 11, 2019 Share Posted May 11, 2019 Post some pics of all the other sides, and keep it all in-frame so the entire specimen is visible. Link to post Share on other sites
ynot Posted May 12, 2019 Share Posted May 12, 2019 As water percolates through rock it will concentrate some minerals in discrete layers (forget what the process is called at the moment). I think that is what this is. So- a concentration of minerals in a layer of the rock, not a fossil. Maybe @Rockwood can remember what it is called. Or maybe it was @Sagebrush Steve that I discussed this with. Link to post Share on other sites
DeepTimeIsotopes Posted May 12, 2019 Share Posted May 12, 2019 43 minutes ago, ynot said: As water percolates through rock it will concentrate some minerals in discrete layers (forget what the process is called at the moment). I think that is what this is. So- a concentration of minerals in a layer of the rock, not a fossil. Maybe @Rockwood can remember what it is called. Are you thinking of dissolution and deposition? Link to post Share on other sites
Rockwood Posted May 12, 2019 Share Posted May 12, 2019 1 hour ago, ynot said: As water percolates through rock it will concentrate some minerals in discrete layers Are you thinking of liesegang banding ? Link to post Share on other sites
ynot Posted May 13, 2019 Share Posted May 13, 2019 1 hour ago, Rockwood said: Are you thinking of liesegang banding ? No. Liesegang banding radiates from a core and tend to be orbicular in nature. Link to post Share on other sites
ynot Posted May 13, 2019 Share Posted May 13, 2019 2 hours ago, UtahFossilHunter said: Are you thinking of dissolution and deposition? That is the process that forms the layers, but not the geologic name. Had a lengthy discussion on the subject with someone here on TFF about a year age, but not sure who it was. This is driving Me nuts........ Link to post Share on other sites
DeepTimeIsotopes Posted May 13, 2019 Share Posted May 13, 2019 26 minutes ago, ynot said: That is the process that forms the layers, but not the geologic name. Had a lengthy discussion on the subject with someone here on TFF about a year age, but not sure who it was. This is driving Me nuts........ There’s “foliation” but that process doesn’t include water... Link to post Share on other sites
ynot Posted May 13, 2019 Share Posted May 13, 2019 Just now, UtahFossilHunter said: There’s “foliation” but that process doesn’t include water... Foliation is the bending of rock by external pressures. Looks nothing like this piece. Link to post Share on other sites
Sagebrush Steve Posted May 13, 2019 Share Posted May 13, 2019 3 hours ago, ynot said: As water percolates through rock it will concentrate some minerals in discrete layers (forget what the process is called at the moment). I think that is what this is. So- a concentration of minerals in a layer of the rock, not a fossil. Maybe @Rockwood can remember what it is called. Or maybe it was @Sagebrush Steve that I discussed this with. No, it wasn’t me. But you’ve got me curious. Hopefully someone will know the name. Link to post Share on other sites
Mark Kmiecik Posted May 13, 2019 Share Posted May 13, 2019 1 hour ago, Sagebrush Steve said: No, it wasn’t me. But you’ve got me curious. Hopefully someone will know the name. Permineralization? Striation? Stratification? Antidisestablishmentarianism? Link to post Share on other sites
Rockwood Posted May 13, 2019 Share Posted May 13, 2019 It looks like simple hydration/oxidation weathering to me. Link to post Share on other sites
DPS Ammonite Posted May 13, 2019 Share Posted May 13, 2019 11 hours ago, ynot said: That is the process that forms the layers, but not the geologic name. Had a lengthy discussion on the subject with someone here on TFF about a year age, but not sure who it was. This is driving Me nuts........ Diffusion banding? Weathering rinds? https://onlinelibrary.wiley.com/doi/full/10.1111/gfl.12056 Link to post Share on other sites
n8state Posted May 13, 2019 Author Share Posted May 13, 2019 This is from another angle. I think perhaps you guys are right and a layer of whatever(?) has been eroded to leave what it is I can see. From this angle you can see that the feature is raised a little. On a separate note, I found some other interesting bits and would like some help identifying but I’m not sure on the etiquette for the forum. Would it be best to include one new topic with a handful of specimens or a new topic for each? Link to post Share on other sites
ynot Posted May 13, 2019 Share Posted May 13, 2019 51 minutes ago, n8state said: I found some other interesting bits and would like some help identifying but I’m not sure on the etiquette for the forum. Would it be best to include one new topic with a handful of specimens or a new topic for each? It is better to limit the number of pieces in one thread and You can start as many threads as You want. If there are more than 1 piece in a thread, please number them. And include a scale. Link to post Share on other sites
abyssunder Posted May 13, 2019 Share Posted May 13, 2019 Septarian - like propagation cracks? Link to post Share on other sites
Rockwood Posted May 13, 2019 Share Posted May 13, 2019 52 minutes ago, abyssunder said: Septarian - like propagation cracks? Or the shape is right for syneresis cracks maybe ? 1 Link to post Share on other sites
abyssunder Posted May 15, 2019 Share Posted May 15, 2019 On 5/14/2019 at 2:47 AM, Rockwood said: Or the shape is right for syneresis cracks maybe ? Maybe, I would agree with you. Link to post Share on other sites
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