Reconstructing orogens without biostratigraphy: The Saharides and continental growth during the final assembly of Gondwana-Land

Abstract

SignificanceA method without biostratigraphy is employed to delineate a hitherto unknown, major orogenic system of Neoproterozoic age in North Africa and Arabia in which some 5 million km2of juvenile continental crust may have been generated in some 400 Ma, i.e., 0.44 km3/a assuming a minimum thickness of 35 km for the generated crust, thus slightly less than the 1/3 of the annual average crustal growth rate globally and similar to the crustal growth rate in the Altaids of Asia between 600 and 140 Ma, supporting the idea that the formation of the continental crust has been continuous throughout earth history, albeit with fluctuating intensity. Our method can be applied to reconstruct other complex Precambrian orogenic systems.