TECTONOSTRATIGRAPHY OF ALBANIAN OPHIOLITES

This paper focuses on tectonostratrigraphy of central Mirdita ophiolites, the most completed and preserved section of Albanian ophiolites. Tectonostratigraphy of Albanian ophiolites- The Albanian (Mirdita) ophiolites complexes consist of westernmost type Triassic-Jurassic ophiolite (Rubiku area) and the western and eastern type Jurassic (Kachinar-Perlat-Reps area) internally disrupted, as displayed by the existence of a stack of thrust sheets in the front and inside the Mirdita ophiolite nappe. Ophiolite complexes from west to east consist from three main thrust sheets: a) The Triassic-Jurassic ophiolite complex or The Rubiku unit, b) The western and eastern type Jurassic ophiolite complex Kachinar-Perlat-Chafe Mali unit or The Perlati unit and c) The metamorphic sole or The Vela unit. The Rubiku unit is overthrusted onto Triassic platform carbonates overlain by Late Jurassic-Early Cretaceous /Early Cretaceous mélange, making up the main front of westward emplacement of Albanian ophiolites. The Perlati unit- Comprises Middle Jurassic Kachinar-Gzik area and Middle Jurassic-early Late Jurassic Chafe Mali-Perlat. The Perlati unit is highly disrupted, as represented by westward-northward thrusting of different levels of ophiolites, taking place after mélange deposition. In the Albanian ophiolites, only the 'Chafe Mali-Reps sheeted dyke dominated segment' is like a typical "Penrose-type ophiolites". The other area ophiolites do not represent the remnants of mature oceanic lithosphere, but rather various stages of oceanic crust formation. All western and eastern type volcanics are overlain by sin-obduction deposits of Late Jurassic-Early Cretaceous mélange whereas different levels of eastern ophiolites are overlain by transgressive post-obduction Berriasian-Valanginian flysch-like deposits and Barremian-Aptian platform limestones. The Vela unit- This metamorphic sole unit consists of greenschist-amphibolite facies and is located along the volcano-sedimentary-ultramafic contact with a thickness from few meters up to 120 meters. The metallogeny reflects the differences in the western and the eastern ophiolites the geotectonic settings and age of generation.