The Palaeoproterozoic in western Anti-Atlas (Morocco): a clarification

Zircon U-Pb data on post-tectonic granites that have intruded the Precambrian formations of the Kerdous inlier (western Anti-Atlas, Morocco) are Pan-African. Zircon grains from a syntectonic monzodiorite of the Tahala pluton yield a precise discordia line with an upper intercept at 2043.9 +/- 1.8 Ma (MSWD = 0.67) interpreted as the emplacement age. This age is consistent with zircon U-Pb ages of granites from other inliers and confirms the existence of a widespread magmatic event at approximate to2045 Ma in the Anti-Atlas. The Pan-African event left no resolvable imprint on the isotopic systems of the analysed zircons. The Kerdous Schists are, therefore, older than 2045 Ma. Rb-Sr and Sm-Nd data on the schists and the Tahala pluton suggest that both juvenile and Archaean material contributed to the generation of the Palaeoproterozoic formations in the Anti-Atlas. (C) 2004 Elsevier Ltd. All rights reserved.