derg Posted February 13, 2017 Share Posted February 13, 2017 Hello! i have found this rock laying on the surface of a dry saharian river. It is a dark blue hard limestone with some fossils in it. This facies is known here as between upper oxfordian and lower Kimmerijian. I think it's a kind of coral. Is it really? i have put some "vaseline codex" on the rock to make it more bright. Sorry for my poor english. Site: Laghouat, Algeria, north africa. Link to comment Share on other sites More sharing options...
Fossildude19 Posted February 13, 2017 Share Posted February 13, 2017 Welcome to the Forum. Maybe these fellows can make a determination. @TqB, ... @FossilDAWG Regards, 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...
Al Dente Posted February 13, 2017 Share Posted February 13, 2017 It looks like a nice example of a Jurassic stromatoporoid. Cladocoropsis is a possibility. 3 Link to comment Share on other sites More sharing options...
TqB Posted February 14, 2017 Share Posted February 14, 2017 I'm with Al Dente, it's not a coral. Nice fossil! 1 Tarquin Link to comment Share on other sites More sharing options...
derg Posted February 15, 2017 Author Share Posted February 15, 2017 Thanks , very helpful! Did anyone tried to obtain a thin rock slice with i may say "a garage tools" ( not those expensive professionl ones)? Link to comment Share on other sites More sharing options...
FossilDAWG Posted February 16, 2017 Share Posted February 16, 2017 I agree, not a coral but a stromatoporoid is a good suggestion. Sections would be nice, but the natural section in the photo you posted is quite good. Don 1 Link to comment Share on other sites More sharing options...
jpc Posted February 16, 2017 Share Posted February 16, 2017 Interesting. I had to look up stromatoporoid Laghouat... I was there a few times many many years ago... 1993. I did find some corals at Taghrit. Link to comment Share on other sites More sharing options...
derg Posted February 16, 2017 Author Share Posted February 16, 2017 (edited) a new photo! Edited February 16, 2017 by derg Link to comment Share on other sites More sharing options...
Wrangellian Posted February 21, 2017 Share Posted February 21, 2017 Interesting! I did think it looked spongish before I saw the comments that followed, but I had assumed that stromatoporoids were restricted to the Paleozoic. Very nice finds. Link to comment Share on other sites More sharing options...
derg Posted February 26, 2017 Author Share Posted February 26, 2017 Yes! very strange fossils theses stromatoporoids! but they were also reef builders in the mesozoic era, especially upper jurassic. Hard to study because they demand thin slices and a microscope, consuming time and money. Here is more other samples of these fossils, same location; Laghouat, Algeria(DZ), North Africa.We can see two new fossils. Washed with water and a brush they look blurry . Wiped with some vaseline they look beautiful. Link to comment Share on other sites More sharing options...
derg Posted February 26, 2017 Author Share Posted February 26, 2017 A photo of the site of findings! Link to comment Share on other sites More sharing options...
TqB Posted February 26, 2017 Share Posted February 26, 2017 This one is a coral (you can see septa), possibly rugose. Could some of these be Palaeozoic? 1 Tarquin Link to comment Share on other sites More sharing options...
derg Posted February 26, 2017 Author Share Posted February 26, 2017 Thank you TqB! palaeozoic? no! the geologic map of this area doesn't show outcrop lower than oxfordian stage. It seem's then that corals and stromatoporoids were sharing the same "paleoecological conditions" i may say. Link to comment Share on other sites More sharing options...
TqB Posted February 27, 2017 Share Posted February 27, 2017 13 hours ago, derg said: Thank you TqB! palaeozoic? no! the geologic map of this area doesn't show outcrop lower than oxfordian stage. It seem's then that corals and stromatoporoids were sharing the same "paleoecological conditions" i may say. Thanks, maybe it's something like Thecosmilia but I don't know much about scleractinians! You have an interesting assemblage there. 1 Tarquin Link to comment Share on other sites More sharing options...
Kosmoceras Posted February 27, 2017 Share Posted February 27, 2017 19 hours ago, TqB said: This one is a coral (you can see septa), possibly rugose. Could some of these be Palaeozoic? 18 hours ago, derg said: Thank you TqB! palaeozoic? no! the geologic map of this area doesn't show outcrop lower than oxfordian stage. It seem's then that corals and stromatoporoids were sharing the same "paleoecological conditions" i may say. Is there a possibility that these are Palaeozoic rock clasts from a Mesozoic conglomerate? 1 Link to comment Share on other sites More sharing options...
derg Posted February 27, 2017 Author Share Posted February 27, 2017 Kosmoceras: geologic map of these area shows that these rock clasts are quaternary conglomérates ( q 3-4 and q 5-6). All theses fossils were already mentioned in their original outcrop ( mountain Lazreg) as jurassic (upper oxfordian- lower kimmeridjian). No paleozoic (outcrop or rock clast) found in this area (Laghouat) since more than a century of geological studies. Link to comment Share on other sites More sharing options...
derg Posted March 4, 2017 Author Share Posted March 4, 2017 My last finding! more likely a coral. Link to comment Share on other sites More sharing options...
abyssunder Posted March 10, 2017 Share Posted March 10, 2017 You might need this document for your corals and stromatoporoids: L. Beauvais and S. Nouiouat. 1993. Une nouvelle faune de coralliaire jurassiques dans l'Atlas sahariens d'Algerie [A new Jurassic coral fauna from the Saharan Atlas of Algeria]. Geobios 26(3):291-318 " This paper contains the description and figuration of fifteen Scleractinian species belonging to fourteen genera. Two species are new. The material comes from three outcrops of the Saharian Atlasis of Algeria. Five genera and one species of Calcisponge have been identified too. This fauna belongs to Late Jurassic, however, four species collected at the top of the Hassi M'Guita series, have been found up to day, exclusively in Middle Jurassic. " Species described include Cladocoropsis memoria-naumanni (YABE). 1927 - Stromatopora memoria-naumanni YABE, p. 90. 1935 - Stromatopora (Parastromatopora) memoria-naumanni YABE in YABE & SUGIYAMA, p. 180, pl. 47-52, 55, 58, 62 et 63. 1982 - Cladocoropsis memoria-naumanni (YABE), Beauvais, p. 41, pl. 1, fig. 3. 1989 - Cladocoropsis memoria-naumanni (YABE), Beauvais, p. 273, pl. 60, fig. 3. Repartition stratigraphique et geographique - Espece tres repandue dans le Jurassique superieur-Berriasien de tout le bassin tethysien (Japon, Philippines, Indondsie, Grace, Italie, Algerie).Localite - Djebel Azreg.Materiel - Une plaque mince (AZG 036). 1 " 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...
derg Posted March 17, 2017 Author Share Posted March 17, 2017 Thank you Abyssunder for this precious document. The association of corals stromatoporoids ans chetaetids is common in upper jurassic reefs of laghouat, Algeria.Here is other photos of stromatoporoids that sometimes seem to show corals like structures in their body. Relation between corals and stromatoporoids is fascinating! Link to comment Share on other sites More sharing options...
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