Tectonic Crossroads: Evolving Orogens of Eurasia-Africa-Arabia

Paper No. 4
Presentation Time: 08:30-18:30

OUTLINE ABOUT GEOSTRUCTURES IN OPHIOLITES OF THE NORTH CENTRAL MIRDITA IN ALBANIA, BASED ON THE INTEPRETATION BY METHODS OF GEOMECHANICS


KOLNDREU, Dede, Rruga Pandi Dardha, Pallati 58, Apt 47, Tirana, Albania, dkolndreu@mail.com

Based on the interpretation of Geostructures by Method of Geomechanics (Kolndreu, 1987, 1988, 1991, 1995, 1996) the Mirdita Ophiolite Complex is a part of the West Reflection Arc of the e- Epsilon type structure of the Balkan Peninsula (J.S. Lee, 1973, 1984) formed during the compression of Euro-Asian against Africa (Mesozoic time).

At the beginning stage (rifting) was formed the MOR-western ophiolites, then the MOR-western ophilolite type evolved into the IAT-boninite-Eastern-type ophiolite (subduction) (Melo, Beccaluva, Shallo, Aliaj, Robertson, Dilek , Bortelotti et al.).

During J3 - Cr1 geological time, after the Ophiolitic-complex forming, it was formed the Structure Ksi Type of Ophiolite Mirdita Zone (folds and faults) with the compressive-shear planes (including the Riedel-type displacement structures, the Structure Lambda Type, S-Type, Vortex and Wrench Structures as well (Spaç, Bulshar, Reps etc.). This interpretation also is conform to the Geochemically Experiments Data about Evolution of the Subduction which explain clearly the milieu where successively occur in subduction zone where oceanic plates sink into the mantel. “Raw materials entering the subduction factory are processed into magmas, which erupt as characteristic arc volcanism and construct continental crust…. This mixing process can create the andesitic crust, the composition of the total crust is still basaltic, nor andesitic (Tatsumi, 2005)”.

The anticlines and synclines are the structures of first order, the fractures are the second order in the Succession of the Generation of the Structural Feature that compound the Ksi Type Structure of Ophiolite Mirdita Zone in Albania.