Nasrrddine Youbi, Linia Tavares Martins , Jose Manuel Munhi, Hassan lbouh, Jose Madeira , El Houssaine Ait Chayeb, and Adelmajid El Boukhari A.
1 Department of Geology, Faculty of Sciences-Semlalia, Cadi Ayyad University.
P.O. Box. 2390, Prince Moulay Abdellah Avenue, Marrakech 40000, Morocco.
2 Centro de Geologia, Departamento de Geologia da Faculdade de Ciencias da Universidade de Lisboa, Edif. C2 50 piso, 1749-016 Lisboa, Portugal. Itm@fc.ul.pt; firstname.lastname@example.org
3 Department of Geology, Faculty of Sciences and Technics-Gubliz, Cadi Ayyad University. P.O. Box.618, Marrakech 40000, Morocco.
4 LATTEX, Departamento de Geologia da Faculdade de Cidncias da Universidade de Lisboa, Edit C2 50 piso, 1749?016 Lisboa, Portugal. email@example.com
An overview on the Late Triassic-Early Jurassic Magmatic Province of
Morocco and Portugal (TJMPMP) is presented. It comprises clastic
rocks sequences interbedded with extrusive basalts, preserved in elongated
rift basins, and their feeder dikes and sills. Paleontologic data
indicates ages that range from Upper Ladinian-Lower Carnian to the Sinemurian
for the sediments, while available 40Ar/39Ar analysis yield a mean age
of 200±1,6 Ma for the volcanics. The volcanologic characteristics
of the TJMPMP are those of confinental basaltic successions. It comprises
subaerial lava flows and pyroclastic deposits, sometimes deposited in lacustrine
environments, and feeder dikes, constituting an interesting volcanic sub-province
of the Central Atlantic Magmatic Province (CAMP) as most outcrops are preserved
as extrusive volcanics. These rocks correspond to low-Ti, quartz
normative, tholeiites displaying very uniform chemical and isotopic characteristics,
showing variable upper crustal contamination. The most primitive
non-contaminated rocks represent a mantle source localised in continental
lithospheric mantle. The nucleation of the rifting process may have
started at two different triple junctions: an RRR junction near Florida,
and a RRT between Africa-lberia-America.