Abstract
A major new Neoproterozoic orogenic system belonging to the larger Pan-African deformational realm, the Saharides, is described in North Africa, which formed from about 900 to 500 Ma ago. The Saharides, a Turkic-type orogenic complex similar to the Altaids of central and northwestern Asia, involved major subduction-accretion complexes occupying almost the entire Arabian Shield and much of Egypt and the small inliers of such complexes farther west to, and including, the Ahaggar mountains. These complexes are formed at least by half from juvenile material representing at least 5 million km2 new continental crust formed during the Neoproterozoic. The Saharides involved no continental collisions until the very end of their history, but evolved by subduction and strike-slip stacking of arc material mainly by pre-collisional coast-wise transport of arc fragments shaved off the Congo/Tanzania cratonic nucleus in a manner very similar to the development of the Nipponides in east Asia, parts of the North American Cordillera and the Altaids. The entire Sahara is shown to be underlain by a double orocline much like the Hercynian double orocline in western Europe and northwestern Africa and not by an hypothetical ‘Saharan Metacraton’. The method here followed may be a fruitful procedure to untangle the structure of some of the Precambrian orogenic belts before life evolved sufficiently to make biostratigraphy feasible.
| Original language | English |
|---|---|
| Pages (from-to) | 2885-2924 |
| Number of pages | 40 |
| Journal | International Journal of Earth Sciences |
| Volume | 111 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Nov 2022 |
Bibliographical note
Publisher Copyright:© 2021, Geologische Vereinigung e.V. (GV).
Funding
First, we thank Renaud Caby, for doing his best to keep us honest by supplying us with information and critique. We are also grateful to Jean-Paul Liégeois, who most generously supplied us with data on the Ahaggar Massif. Dan McKenzie informed us of the anomalously thin lithosphere under the entire Saharides. We also thank Wim Spakman for informative conversations on the seismic tomographic observations and their interpretation under the Sahara. Anke M. Friedrich gave us access to the rich map collection of the historical Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians Universität München. Abdelrahman Khalifa, most kindly provided us with the 1:500,000 scale geological maps of Egypt during the difficult times of the pandemic. Mehran Basmenji and Müge Yazıcı digitised some of the geological maps we used. Attila Çiner informed us of the recent volcanological literature of Patagonia. We are most grateful to the personnel of the İTÜ Mustafa İnan Library for making it possible for us to use its great map collection during the pandemic, when the university was essentially closed. None of the persons named above can be held responsible for what is written in this paper. Its errors of omission and commission are entirely ours. N. Lom acknowledges NWO Vici Grant 865.17.001. First, we thank Renaud Caby, for doing his best to keep us honest by supplying us with information and critique. We are also grateful to Jean-Paul Liégeois, who most generously supplied us with data on the Ahaggar Massif. Dan McKenzie informed us of the anomalously thin lithosphere under the entire Saharides. We also thank Wim Spakman for informative conversations on the seismic tomographic observations and their interpretation under the Sahara. Anke M. Friedrich gave us access to the rich map collection of the historical Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians Universität München. Abdelrahman Khalifa, most kindly provided us with the 1:500,000 scale geological maps of Egypt during the difficult times of the pandemic. Mehran Basmenji and Müge Yazıcı digitised some of the geological maps we used. Attila Çiner informed us of the recent volcanological literature of Patagonia. We are most grateful to the personnel of the İTÜ Mustafa İnan Library for making it possible for us to use its great map collection during the pandemic, when the university was essentially closed. None of the persons named above can be held responsible for what is written in this paper. Its errors of omission and commission are entirely ours. N. Lom acknowledges NWO Vici Grant 865.17.001.
| Funders | Funder number |
|---|---|
| Department für Geo- und Umweltwissenschaften | |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 865.17.001 |
| Ludwig-Maximilians-Universität München |