Anti-Atlas (Morocco) role in Neoproterozoic Western Gondwana reconstruction

Reconstruction of latest Neoproterozoic Gondwana hinges on the interpretati on of the subduction and collision kinematics of pan-African orogenic belts that rim the West African craton. The Anti-Atlas suture zone of southern M orocco has presented an enigma in this reconstruction as the inferred subdu ction zone polarity and age of suturing appear to be incongruous with bette r known West African orogens to the west (Mauretanian, Bassaride and Rokeli de) and Transaharan orogens to the east (Ougarta, Tuareg, Gourma and Dahome yan). Contrary to previous interpretations, new data from the Anti-Atlas in dicate a history of late Neoproterozoic (similar to 750-600) north-dipping subduction culminating in the (similar to 600 Ma) collision of the Saghro m agmatic are to the north with the north-facing rifted margin of the West Af rican craton. Thus, the Anti-Atlas suture links a similar to 6000-km long c hain of Pan-African suture zones that essentially encircle the West African craton. The suture zones demarcate the former position of subduction zones that in all cases dipped away from the West African craton. The Anti-Atlas suture links the western and eastern segments of the Pan-African orogenic belts associated with the amalgamation of Western Gondwana. (C) 2000 Elsevi er Science B.V. All rights reserved.