The role of the Kyrenia Range Lineament, Cyprus, in the geological evolution of the eastern Mediterranean area

Abstract

Rewarding insights into major crustal lineaments come from the integrated study of well exposed examples. One is the Kyrenia Range, a narrow arcuate lineament of several hundred kilometres in length comprising northern Cyprus and its offshore extension. The Kyrenia Range consists mostly of Mesozoic and Tertiary sedimentary and subordinate volcanic and metamorphic rocks, disposed in four rock groups separated by unconformities recording deformation events. The lineament is dominated by a steeply dipping composite thrust pile located partly along, and partly straddling, the abrupt northward termination of crust similar to the Troodos Igneous Complex at depth. The 200 Ma history of the lineament involved episodic rift, passive-margin, active-margin, strike-slip and uplift phases. The area was rifted off Gondwana in the late Triassic to form a southerly Turkish microcontinent capped by a gently subsiding carbonate platform. After formation of a small ocean basin to the south during the Cretaceous (Troodos ocean), northward subduction began (?Santonian). The first major deformation (D1) is attributed to pervasive (?dextral) strike-slip, which removed the Mesozoic passive margin and brecciated and metamorphosed the remaining platform. In the Maastrichtian and early Tertiary the area subsided and scree breccias were shed from scarps into pelagic carbonate-depositing seas, while bimodal within-plate-type lavas were erupted in an extensional setting influenced by strike-slip. By mid Eocene time, shortening, first evidence by flysch and olistostrome deposition, culminated in strong southward thrusting (D2) and localized metamorphism. Northward subduction south of Cyprus ensued and the range lay in an extensional fore-arc setting in late Eocene and Miocene time. The area then subsided dramatically and accumulated thick turbidite sequences derived from eroding Tauride Mountain areas to the northeast. Faulting and general uplift in the late Miocene was followed by renewed compressional deformation climaxing in mid Pliocene time (D3) with large-scale thrusting and tilting. Pulsed vertical uplift continued through the Quaternary. Similar volcanic and metamorphic rocks formed along the Kyrenia Lineament at intervals. Sedimentary rocks emerge as the most sensitive tectonic setting indicators. Long-lived lineaments like the Kyrenia Range are inherently very complicated, and perceived simple solutions in other cases should be viewed with some scepticism.