Skip to main content

The Jurassic-Cretaceous Magmatic Complexes of the Eastern High Atlas, Morocco

Located in the eastern part of the High Atlas Mountains, the Upper Jurassic-Lower Cretaceous magmatic complexes intrude predominantly along the thick Mesozoic sedimentary anticlinal ridge and within the Mouguer-El’Bour Paleozoic inlier. They are range in composition from mafic to felsic, including gabbro, diorite, and syenite.
Petrography admits that these intrusions show three types of gabbro as mafic facies: ordinary, biotite-bearing, olivine-bearing Gabbro as for the intermediate term diorite then the syenite.
Ordinary and biotite-bearing Gabbro are mostly coarse-grained and composed mainly of euhedral plagioclase, clinopyroxene, Biotite, alteration minerals including amphiboles, chlorite, sericite, and epidote, secondary minerals like apatite, sphene and opaque minerals included in the biotite grains. As for the olivine bearing Gabbro, olivine euhedral minerals are abundant with serpentinization faces mainly in the cracks these facies are exclusively found in the Tazmamart intrusion. Diorite is the intermediate facies it mainly comprises plagioclase, clinopyroxene, amphiboles, opaque minerals, and apatite. The syenites comprise aphanitic to phaneritic textures with both potassic, plagioclase feldspar and quartz which combined in a mermekitic texture, amphiboles, opaque minerals, apatite, and sphene.
Previous geochemical studies reveal a trend from mafic to felsic rocks, with transitional to alkaline affinities. These studies indicate a heterogeneous mantle source. Several researchers suggest that these magmatic intrusions occurred during the late Jurassic to Cretaceous period, which coincides with the closure of ocean basins and the final phase of continental plate collision.
We attempt to undertake mineral geochemistry in order to gain additional insight on magmatic process and the origin of these intrusions.

Details

Author
NASSIRA CHAFIK1, BRAHIM KARAOUI1, Mustapha ALLOUBAN1, Hripsime GEVORGYAN2, Zakaria YAJIOUI1
Institutionen
1Laboratory of Applied Geology, Faculty of Sciences and Techniques (Errachidia), Moulay Ismail University of Meknes, Morocco; 2Mineralogy Institute, University of Technology Bergakademie Freiberg, Germany
Veranstaltung
GeoSaxonia 2024
Datum
2024
DOI
10.48380/4qh5-8212