This question is for an updated paleogeographical reconstruction of the Atlas Gulf and assiociated landmasses in the Early Jurassic (Early Toarcian)
We know that this Paleozoic montane rangue was exposed on the EJ (Frizon de Lamotte et al., 2008), that was being pushed by two rift systems (the Tethyan Atlas rift in the north and the Atlantic rift in the west) and that there was an ongoing exhumation, that cutaround 7.5–10.5 km of crustal rocks by the end of the Middle Jurassic (Gouiza et al., 2017). As well there is evidence it was a source for siliclastic materials in the Early Jurassic Atlas Gulf (Krencker et al. 2020).
But, is there any suggested reconstrucion of it´s appperance? Or a suggestion of what it may have looked like?
-Frizon de Lamotte, D., Zizi, M., Missenard, Y., Hafid, M., Azzouzi, M. E., Maury, R. C., ... & Michard, A. (2008). The atlas system. Continental Evolution: The Geology of Morocco: Structure, Stratigraphy, and Tectonics of the Africa-Atlantic-Mediterranean Triple Junction, 133-202.
-Gouiza, M., Charton, R., Bertotti, G., Andriessen, P., & Storms, J. E. A. (2017). Post-Variscan evolution of the Anti-Atlas belt of Morocco constrained from low-temperature geochronology. International Journal of Earth Sciences, 106, 593-616.
-Krencker, F. N., Fantasia, A., Danisch, J., Martindale, R., Kabiri, L., El Ouali, M., & Bodin, S. (2020). Two-phased collapse of the shallow-water carbonate factory during the late Pliensbachian–Toarcian driven by changing climate and enhanced continental weathering in the Northwestern Gondwana Margin. Earth-Science Reviews, 208, 103254.
I am sure that some of the Moroccan colleagues can give a more detailed answer but it is for sure that there was already significant erosion in the post-Variscan Palaeozoic. The famous outcrop of Ouidane Chebbi and other Kem-Kem outcrops show a medium-scale hill and valley Devonian-Carboniferous topography transgressed by flat lying Cretaceous beds. So it seems that there was no alpine-style mountain range left in the Jurassic.
Ralph Thomas Becker Interesting. Makes sense with the expected 7.5–10.5 km erosion in the MJ. Then, I have doubts because the Anti-Atlas was still hit by 2 main rift systems and and perhaps continued to fold... The only thing that seems to be clear is that it was a (possible) source of sediment.
But it definitely did not have the massive topography suggested for the Carbo-Permian.
Thanks for your answer!
Dear Antonio García Palmeiro ,
I am not so familiar with the area you are researching. 27 years before I had to leave the profession... But since then I've been working in my former profession as a hobby... You should pay attention to what Ralph Thomas Becker said : 'The famous outcrop of Ouidane Chebbi and other Kem-Kem outcrops show a medium-scale hill and valley Devonian-Carboniferous topography transgressed by flat lying Cretaceous beds. So it seems that there was no alpine-style mountain range left in the Jurassic.'! Very logical!
If you look at his work he made paleontological study near the East of Anti-Atlas Range: Dra Walley... That is why you can use as prove his works... Regardless of that, without doing any research there - there is no possibility to do - my opinion was that the area worked as continental medium in Jurassic... You don't have an easy job... You need to do research in East (West Algeria, There has to exist drilling's Data! and seismic 3D surveys, 2D seismic sections) . In principle, you should be thinking about what the Moroccan Anti-Atlas would have looked like in the Early Jurassic nearly as it looks now... Only its West, North-West Area had other features. you have to determine correctly, why? I cannot say more about Hungary from here... It is clear what you have to do.
Regards,
Laszlo
László Attila Horváth You´re right. I already got seismic data and all point to a Tophography of less than 2000 m. Then, I still need some opinions
Dear Antonio ( Antonio García Palmeiro ),
For other options you have to read through the literature related to this area... , mostly French literature, and meanwhile you have to think about what is wrong with the options... I had one reservation about the recommended option, but can be eliminated...
Regards,
Laszlo