Is the Cambrian basin of the Western High Atlas (Morocco) related either to a subduction zone or a major shear zone?
✍ Scribed by A. El Archi; M. El Houicha; A. Jouhari; M. Bouabdelli
- Publisher
- Elsevier Science
- Year
- 2004
- Tongue
- English
- Weight
- 550 KB
- Volume
- 39
- Category
- Article
- ISSN
- 1464-343X
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✦ Synopsis
By its geological and structural position, the Palaeozoic massif of the western High Atlas constitutes a hinge between the Anti-Atlasic domain in the South and the domain of Meseta in the North. The upper Proterozoic and lower Palaeozoic formations of the Anti-Atlas and the Cambrian successions of coastal Meseta are well known, while a synthetic vision of the western High Atlas coeval sequences is lacking.
Recent field and analytical work performed on low-grade metamorphic rocks of the Moroccan ''High Atlas old Massif'' allows us to distinguish several sedimentary sequences and interbedded (essentially effusive) magmatic rocks, the geochemical characterization of which forms the main aim of this paper.
By comparison with adjacent areas, the age of the metasedimentary rocks is attributed to the late Neoproterozoic and lower Palaeozoic. The volcanic rocks have calc-alkaline (late Neoproterozoic and lower Cambrian), alkaline and/or tholeiitic (Middle Cambrian) affinities.
The results of this study impose some constraints on understanding the palaeogeographic links between the Anti-Atlas and the Moroccan Meseta during the Neoproterozoic-Cambrian transition.