Relación entre los macizos de Temsamane y Ketama en la Semiventana de Beni- Malek (Rif Oriental, Marruecos) Relationships between the Temsamane and Ketama Massifs in the Half-Window of Beni-Malek (Eastern Rif, Morocco)

Observations at Beni-Malek allow us to propose that the Temsamane units are the relative autochthonous of the Tanger-Ketama metamorphic Unit. There is a body of serpentinized peridotites (Beni-Malek Peridotites) within the main thrust surface that overlays 5 to 10 meters of mylonitic marbles with a ENE-WSW-trending stretching lineation and a top-to-.the-WSW sense of movement. The serpentinized peridotites have remains of pyroxene but no olivine, which is transformed to the low temperature polymorphs of serpentinite with a typical deformed mesh texture. Also, a fine grained aggregate of antigorite, the high temperature polymorph of serpentine can be observed, suggesting that the transformation to antigorite was induced by deformation at least under 300 oC. Rocks from the Temsamane units have reached epizone metamorphic conditions, which agree with the conditions deduced from the serpentinites.