The Neogene Taza-Guercif Basin, in north-eastern Morocco, is located in correspondence of the eastern termination of the Rifian arc and is aligned along with the Middle Atlas Shear Zone. Since Tortonian the tectonic evolution of the Taza-Guercif Basin was tied to repeated advancements of the Rifian front and to the transpressive tectonics of the Middle Atlas Shear Zone. The major structures in this basin consist of thrust-related anticlines, aligned along with the Middle Atlas structures, and second-order normal faults, elongated according to the Rifian trend. The latter are well developed mainly in the north-western sector of the basin (Bab Stout Area). Apart from the Bab Stout Area, the basin is dominated by compressive and transpressive structures (Guercif Transpressive Area). The shortening directions responsible for the development of the major and minor compressive structures in the basin vary from NNW to NNE, but no superposition relationships have been found. This change of the paleo-stress field orientations is here ascribed to a progressive deformation under the constant push between Africa and Europe. An evolutionary model for the development of these two structural areas in relation to the tectonics of the Rif and of the Middle Atlas is here proposed. In this model, the sinistral transpressive Middle Atlas Shear Zone is regarded as the boundary between the Moroccan Meseta microplate, to the west, and the African indenter to the east, which is moving faster to the north. (C) 2000 Elsevier Science Ltd. All rights reserved. The Neogene Taza-Guercif Basin, in north-eastern Morocco, is located in correspondence of the eastern termination of the Rifian arc and is aligned along with the Middle Atlas Shear Zone. Since Tortonian the tectonic evolution of the Taza-Guercif Basin was tied to repeated advancements of the Rifian front and to the transpressive tectonics of the Middle Atlas Shear Zone. The major structures in this basin consist of thrust-related anticlines, aligned along with the Middle Atlas structures, and second-order normal faults, elongated according to the Rifian trend. The latter are well developed mainly in the north-western sector of the basin (Bab Stout Area). Apart from the Bab Stout Area, the basin is dominated by compressive and transpressive structures (Guercif Transpressive Area). The shortening directions responsible for the development of the major and minor compressive structures in the basin vary from NNW to NNE, but no superposition relationships have been found. This change of the paleo-stress field orientations is here ascribed to a progressive deformation under the constant push between Africa and Europe. An evolutionary model for the development of these two structural areas in relation to the tectonics of the Rif and of the Middle Atlas is here proposed. In this model, the sinistral transpressive Middle Atlas Shear Zone is regarded as the boundary between the Moroccan Meseta microplate, to the west, and the African indenter to the east, which is moving faster to the north.
Structural development of the Taza-Guercif Basin as a constraint for the Middle Atlas Shear Zone tectonic evolution
Moratti G;
2000
Abstract
The Neogene Taza-Guercif Basin, in north-eastern Morocco, is located in correspondence of the eastern termination of the Rifian arc and is aligned along with the Middle Atlas Shear Zone. Since Tortonian the tectonic evolution of the Taza-Guercif Basin was tied to repeated advancements of the Rifian front and to the transpressive tectonics of the Middle Atlas Shear Zone. The major structures in this basin consist of thrust-related anticlines, aligned along with the Middle Atlas structures, and second-order normal faults, elongated according to the Rifian trend. The latter are well developed mainly in the north-western sector of the basin (Bab Stout Area). Apart from the Bab Stout Area, the basin is dominated by compressive and transpressive structures (Guercif Transpressive Area). The shortening directions responsible for the development of the major and minor compressive structures in the basin vary from NNW to NNE, but no superposition relationships have been found. This change of the paleo-stress field orientations is here ascribed to a progressive deformation under the constant push between Africa and Europe. An evolutionary model for the development of these two structural areas in relation to the tectonics of the Rif and of the Middle Atlas is here proposed. In this model, the sinistral transpressive Middle Atlas Shear Zone is regarded as the boundary between the Moroccan Meseta microplate, to the west, and the African indenter to the east, which is moving faster to the north. (C) 2000 Elsevier Science Ltd. All rights reserved. The Neogene Taza-Guercif Basin, in north-eastern Morocco, is located in correspondence of the eastern termination of the Rifian arc and is aligned along with the Middle Atlas Shear Zone. Since Tortonian the tectonic evolution of the Taza-Guercif Basin was tied to repeated advancements of the Rifian front and to the transpressive tectonics of the Middle Atlas Shear Zone. The major structures in this basin consist of thrust-related anticlines, aligned along with the Middle Atlas structures, and second-order normal faults, elongated according to the Rifian trend. The latter are well developed mainly in the north-western sector of the basin (Bab Stout Area). Apart from the Bab Stout Area, the basin is dominated by compressive and transpressive structures (Guercif Transpressive Area). The shortening directions responsible for the development of the major and minor compressive structures in the basin vary from NNW to NNE, but no superposition relationships have been found. This change of the paleo-stress field orientations is here ascribed to a progressive deformation under the constant push between Africa and Europe. An evolutionary model for the development of these two structural areas in relation to the tectonics of the Rif and of the Middle Atlas is here proposed. In this model, the sinistral transpressive Middle Atlas Shear Zone is regarded as the boundary between the Moroccan Meseta microplate, to the west, and the African indenter to the east, which is moving faster to the north.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
