Abstract

Detailed mapping of the Bitlis suture zone near Lake Hazar shows that it is composed of three tectonostratigraphic units which crop out as distinct north-dipping thrust slices. From south to north, these are the Puturge Metamorphic Complex, the Maden Mélange, and the Elazig Igneous Complex. The Puturge Metamorphic Complex consists of pre-Tertiary, continental-margin sediments metamorphosed to the greenschist facies during the Campanian-Maastrichtian and deformed by four generations of structures. These are, in sequence (1) isoclinal folds and a transposition foliation, (2) open folds, crenulation cleavage, and north-dipping thrust faults, (3) kink bands, and (4) small-displacement faults. The Maden Mélange represents middle Eocene, back-arc-basin sediments and volcanics metamorphosed to the greenschist facies and deformed by three generations of structures: (1) a north-dipping cleavage, (2) kink bands, and (3) small-displacement faults. The Elazig Igneous Complex comprises an imbricated Maastrichtian-early Eocene island arc and young marginal-basin terrain. Thrust faults between units are north-dipping, listric, and form a thin-skinned system.

These features suggest the following deformational and tectonic history. The Puturge Metamorphic Complex was generated by isoclinal folding and metamorphism of sediments composing the Arabian continental margin during Campanian-Maastrichtian ophiolite obduction to the south. The Elazig arc developed on the deformed margin because of subsequent southward subduction of oceanic lithosphere. The arc migrated to the north, opening a back-arc basin. By the early Eocene, the back-arc basin was filling with volcaniclastics of the Maden Mélange, and the Elazig arc collided with a continent to the north. During middle to late Eocene, convergence caused thrust stacking of the Elazig, Maden, and Puturge Complexes; second-generation deformation in the Puturge Complex; and first-generation deformation in the Maden Mélange. Continued convergence with the Arabian plate in the late Miocene caused kink banding in the Puturge and Maden Complexes. Since the late Miocene, this convergence has been accommodated by shortening and thickening along numerous internal faults.

First Page Preview

First page PDF preview
You do not currently have access to this article.