Petrographie et geochimie des roches magmatiques basiques de la region de bellara et de la region d’amrioune

Abstract

During the Jurassic; Intense magmatic activity accompanied the Rifting and openness, and subsidence and installation of the open sea, This magmatism is well represented at the Kabylie of Collo and El Milia (N E Algeria) that exhibited by the diversity of basic and ultrabasic rocks, in this epoch that it diabase volcanic activity in the series of Achaiches (south of El Milia) . The studed magmatic rocks is outcropping in the south of El Milia in the region to Bellara and Mat Amrioune are a clear example of the basic rocks of the region known, it is of tholeiitic basalts ophitic texture for the region Bellara have been up to the surface by Triassic formations and crossed the Oligo Miocene Kabyl materials and sandstone numidien, however magmatic rocks at Amrioune it is the tholeiitic basalts, it’s in dyke, this rocks have a doleritic texture intruding the middle of Mauritanian flyschs épimétamorphic of achaichs the series. The main minerals forming these rocks are plagioclase, clinopyroxene (diopside) and the secondary minerals (chlorite, epidote, calcite, quartz, hematite, magnetite and ilmenite) The geochemical data of magmatic rocks in question have been correlated with major geodynamic events of the Western Mediterranean sea.