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3. Neotethys: Turkey |
Middle East Technical University, Institute of Marine Sciences, Erdemli-
çel, Turkey
The ‘Ankara Melange’, as defined by Bailey & McCallien (1953), comprises several belts, sub-belts and lenses of melange units, as well as some intercalated ocean floor fragments and continental (magmatic arc?, island arc?) slivers. Two significant observations are the successive younging of melange units from north to south (or northwest to southeast locally) and mega-debris flow features in some of melange units indicating a possible flow direction from east to west (or northeast to southwest). Both observations can be explained by assuming an obliquely northward moving Tethys ocean plate, subducting under a continental mass against which successive accretion and obduction of ocean floor irregularities (such as ocean plateaux, ridges, magmatic island arcs or even continental slivers) from Early Jurassic times to Middle Oligocene, produced the present complex melange system. Flow features can be explained by the development of local high ground where a non-subducting oceanic platform transpressed obliquely against the already-formed melange material, causing it to flow successively to depressed (trench) regions. Such flows were naturally interbedded with, or accompanied by, other types of mass flows and slivers of continental and/or oceanfloor material.
