Tidgy's Dad Posted July 13, 2015 Share Posted July 13, 2015 I bought this recently in Agadir for only $25 so I'm happy whatever it is. It is said to be a stromatolite, though it may be just a desert rose of some type, though it's very hard and heavy, definitely not gypsum or barite. Some sites on the net suggest precambrian, ranging from 2.6 down to .6 billion years old, depending where you look. Some say Cambrian, some Ordovician and others Devonian or Cretaceous. Any ideas anyone? Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Raggedy Man Posted July 13, 2015 Share Posted July 13, 2015 Definitely a stromatolite and a nice sized one! Here's mine. It's from the lower cretaceous, Tagana formation.Ken-kem region. Ksar-es Souk, Morocco ...I'm back. Link to comment Share on other sites More sharing options...
Auspex Posted July 13, 2015 Share Posted July 13, 2015 It's a lovely example! Certainly a good match for many of the Sahara stromatolite images I can Google up. You are right, though, about the dating being all over the map... "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
abyssunder Posted July 13, 2015 Share Posted July 13, 2015 Also from Morocco,one in my collection. " 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...
Tidgy's Dad Posted July 13, 2015 Author Share Posted July 13, 2015 Definitely a stromatolite and a nice sized one! Here's mine. It's from the lower cretaceous, Tagana formation.Ken-kem region. Ksar-es Souk, Morocco 20150713_155214.jpg Yes, these Cretaceous ones are similar, but not as orange as the desert ones, altogether paler. Thanks, nice looking one you have there. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 13, 2015 Author Share Posted July 13, 2015 It's a lovely example! Certainly a good match for many of the Sahara stromatolite images I can Google up. You are right, though, about the dating being all over the map... Thanks, it's a beauty, I checked every image I could find on Google for these orange ones and it is, as you say, rather conflicting. My collection's arranged by geological period, so I don't know where to place it. I'd love it to be Pre-Cambrian, but I don't honestly think it's that old, i've seen the Pre cam stroms from some areas here and they're much harder, massive and layered. Hmmm. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 13, 2015 Author Share Posted July 13, 2015 Also from Morocco,one in my collection. 100_4304a.jpg That's beautiful! Do you have a location and age? Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Auspex Posted July 13, 2015 Share Posted July 13, 2015 ...My collection's arranged by geological period, so I don't know where to place it... "Timeless" has a nice ring to it... "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 13, 2015 Author Share Posted July 13, 2015 "Timeless" has a nice ring to it... It does. So in my music collection, then? Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Auspex Posted July 14, 2015 Share Posted July 14, 2015 There might be a paper out there addressing these. What do we have to go on, location-wise? "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
ZiggieCie Posted July 14, 2015 Share Posted July 14, 2015 Tidgy's Dad, we are going to love seeing your collection of "REAL" fossils "FROM" Morocco. PS. I love your Fez. I have thought those were great hats since I was a kid, I'm 63 now, and they are still great. Ziggie Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 14, 2015 Author Share Posted July 14, 2015 There might be a paper out there addressing these. What do we have to go on, location-wise? Just that it's from the Sahara. The guy in the shop in Agadir was vague, but I've seen plenty like this here and on the net. It's real, but I'm just not sure about the age. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Ebo Posted July 14, 2015 Share Posted July 14, 2015 (edited) I'm sorry to deceive you, but these aren't stromatolites, but structures that are formed through rich mineral water deposition. I've had a long discussion with a colleague that extract these structures from the Moroccan site, and at this time I believe that are stromatolites too. He says not, I'm saying yes... He show me some pictures from the extraction site... then I was convinced that aren't stromatolites. Here are some pictures that show these concretions. It is interesting to see also that doesn't exist any internal layered structure when you cut and polish these spherical structures (see image below), growing structures that are in general well visible in "normal" stromatolites. I haven't this paper, but these structures are described in this way: According to Lavocat (1954b), fossils are sometimes concentrated at the surface by erosion but most of these concentrations have now vanished as a result of continuous surface collecting. At these more ephemeral localities fossils are associated with the kerkoub facies (Fig. 4C), characterized at the surface by concentrations of sandstone spheres that range from around 2 to 10 cm in diameter (Lavocat, 1954). Lavocat, R., (1954). Reconnaissance géologique dans les Hammadas des confins algéro-marocains du Sud. Notes et Mémoires du Service Géologique du Maroc 116. 147 p. At my knowledge, the only commercial Moroccan Precambrian stromatolites are coming from the Tachgagalt Formation, in the Ouarzazate Supergroup (Amane n'Tourhart, Ouarzazate), like the Collenia specimen shown here (from my collection): Enrico Edited July 14, 2015 by Ebo 2 ********************* Enrico Bonino https://www.facebook.com/BackToThePastMuseum/ http://www.backtothepast.com.mx/ebonino Trilobite viewer: https://arcg.is/0iWWvL ********************* Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 14, 2015 Author Share Posted July 14, 2015 Stromatolites with definite layered structures are found at Tiout, Agdz and Imgur, (maybe not all commercial sites). The sort you show are the alleged Cretaceous pale ones found at Saf-saf, Merzouga and Khenifra. Others come from Erfoud and in the Sahara and Western Sahara. You may well be right that they are just concretions, but if Lavocat in 1954 suggested these concretions were mostly gone due to surface collecting, why are these things still so abundant? I think in 1954, most Moroccan localities were still unknown. However, my logic is telling me they are probably not fossils, my heart still hopes they are. Thank you for your information. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Auspex Posted July 14, 2015 Share Posted July 14, 2015 The question really is whether these accreted by biological or lithological process. It may be pretty hard to tell. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Ebo Posted July 14, 2015 Share Posted July 14, 2015 Auspex, this is an interesting question. I'm pretty sure that bacteria can be present during the deposition of CaCO3 or other minerals, functioning as catalytic. But in this particular situation, the sandstone is quite an unusual and raw matrix for the stromatolites sensu strictu as we know. These structures (collenia, cryptozoon, thrombolites, oolithes...) develop in general in quiet environments (lagoons -but not only like the oolithes/onchoids-), with hypersaline water, in general lime or very fine dolomite sediments are the principal component of the matrix, and not sand that is more related to detritic presence, not very well appreciated by the algal mats... This is an open question and very interesting to analyze (even taken in account in astrobiology, in searching for extraterrestrial life in other planets). Enrico ********************* Enrico Bonino https://www.facebook.com/BackToThePastMuseum/ http://www.backtothepast.com.mx/ebonino Trilobite viewer: https://arcg.is/0iWWvL ********************* Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 15, 2015 Author Share Posted July 15, 2015 This picture seems to show layering. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 15, 2015 Author Share Posted July 15, 2015 And this one. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Ebo Posted July 16, 2015 Share Posted July 16, 2015 I bought some years ago this "stromatolites" coming from the same site, and I believe that was a real stromatolites too (before the discussion with the guy working on place and send me the picture that I show you): You can see the evident layering due to the atmospheric elements erosion, the "bubbled surface" that remember well the "growing gems" of some algal mats and the smoothed general surface. Just at today I haven't seen any official paper published about these "stromatolites", nor the exact location where these forms come from; may be you can greatly help us to localize the site with a latitude/longitude point. This is really useful to find the geologic formation (then the correct age) and if we are lucky the environment deposition if the geologic map of Morocco contain the related information. ********************* Enrico Bonino https://www.facebook.com/BackToThePastMuseum/ http://www.backtothepast.com.mx/ebonino Trilobite viewer: https://arcg.is/0iWWvL ********************* Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted July 17, 2015 Author Share Posted July 17, 2015 I don't have the location, though there are several supposed localities for this type of 'fossil'. The greyer ones like yours are supposedly from further north and the yellowish ones, like mine from the Sahara. I will look into it. Life's Good! Tortoise Friend. 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