Page "Geography of Turkey" Paragraph 18

During the Mesozoic era ( about 250 to 65 million years ago ) a large ocean ( Tethys Ocean ), floored by oceanic lithosphere existed in-between the supercontinents of Gondwana and Laurasia ( which lay to the south and north respectively ; Robertson & Dixon, 2006 ).

This large oceanic plate was consumed at subduction zones ( see subduction zone ).

At the subduction trenches the sedimentary rock layers that were deposited within the prehistoric Tethys Ocean buckled, were folded, faulted and tectonically mixed with huge blocks of crystalline basement rocks of the oceanic lithosphere.

These blocks form a very complex mixture or mélange of rocks that include mainly serpentinite, basalt, dolerite and chert ( e. g. Bergougnan, 1975 ).

The Eurasian margin, now preserved in the Pontides ( the Pontic Mountains along the Black Sea coast ), is thought to have been geologically similar to the Western Pacific region today ( e. g. Rice et al., 2006 ).

Volcanic arcs ( see volcanic arc ) and backarc basins ( see back-arc basin ) formed and were emplaced onto Eurasia as ophiolites ( see ophiolite ) as they collided with microcontinents ( literally relatively small plates of continental lithosphere ; e. g. Ustaomer and Robertson, 1997 ).

These microcontinents had been pulled away from the Gondwanan continent further south.

Turkey is therefore made up from several different prehistorical microcontinents.