The geology of Cyprus and its place in the East-Mediterranean framework

Abstract

New datings and sedimentological observations seem to confirm the Cretaceous age and submarine origin of the Troodos igneous complex in central Cyprus. Troodos rocks, of marked calc-alkali character, form the basement to an Upper Maastrichtian-Tertiary sequence, 500-1800m thick, of bathyal-shallow abyssal marls and chalks. In N Cyprus these relatively undisturbed sediments are in contact with southward thrusted flysch deposits (2000-3000 m) of prevailing Miocene age, indicating a tectonic weld of major order. Allochthonous Permian-Lower Cretaceous shelf limestones are exposed in what seems to be the core (Kyrenia Range) of the N Cyprus thrust belt. In SW and S Cyprus a thin, exotic rock complex (Mamonia) wedges in between the Upper Maastrichtian-Tertiary sediments and Troodos basement. The Mamonia comprises a Triassic- Lower Cretaceous allochthonous, mainly deep marine assemblage that rests on Campanian dated andesitic pyroclastics. The geological evolution of Cyprus is conceived by the authors as follows: The Troodos igneous complex formed part of an ocean rise in a Cretaceous sea bordered by continental margins. In about Campanian time Troodos was underthrust by the southern (Afro-Arabian) margin. Some of the continental margin rocks (the allochthonous Mamonia), preceded by pyroclastic slope deposits, came to rest on the leading edge of Troodos. The andesitic source of the pyroclastics was probably in the former margin. Quartz sandstone blocks of Lower cretaceous age, included in the allochthonous assemblage, are possibly Nubian sandstones derived from the southern continent. Continued underthrusting forced Troodos to rise without disturbing its sedimentary cover. Eventually, in the upper Miocene and Pliocene, slope deposits and detached shelf limestones from a northern(? ) source were thrust on the Troodos north flank. The tectonic setting of Cyprus is analogous to that of other peri-Arabian thrust belts in that ophiolite/deep-sea sediment associations appear thrown on the southern continent. The Troodos "ophiolite", however, seems unique because of its enormous size and relative rigidity.