Late Eocene–Neogene sedimentary geology of the Girne (Kyrenia) Range, northern Cyprus: A case history of sedimentation related to progressive and diachronous continental collision

Abstract

Sedimentary geology can shed light on the processes of continental collision. The easternmost Mediterranean provides an exceptional opportunity to study sediments deposited during progressive and diachronous continental collision, with implications for comparable settings elsewhere. Here, we focus on sediment sources, pathways and deposition of mostly deep-sea clastic sediments exposed in northern Cyprus. The sedimentary basin forms part of the northern continental margin of the Southern Neotethys ocean and is represented by a ca. 200km-long, E–W-trending, arcuate lineament, encompassing northern Cyprus and its submarine link with Turkey. The Upper Eocene–Upper Miocene basin was divided into northerly and southerly sub-basins during Mid- to Late Miocene time by an E–W-trending, inferred syn-depositional fault lineament. The sequence begins with non-marine to shallow-marine basal conglomerates (Late Eocene) that abruptly fine upwards into siliciclastic turbidites (Oligocene), followed by biogenic calciturbidites and marls (Aquitanian–Langhian). During Mid–Late Miocene the northerly sub-basin was characterised by thin- to medium-bedded calciturbidites and marls (Serravallian), overlain by thick-bedded, medium-grained lithic sandstones (Tortonian). In contrast, the southern sub-basin is dominated by siliciclastic turbidites with abundant sole structures (Burdigalian–Tortonian). Palaeocurrent evidence indicates dominantly westward sediment transport, especially during the Late Miocene. The Serravallian–Tortonian sandstones of the northern sub-basin are relatively rich in carbonates, while the southern sub-basin contains more siliciclastic and ophiolite-derived detritus indicating differences in sediment supply. In general, the Upper Eocene basal conglomerates were mainly derived from the north, from within the Girne (Kyrenia) Range and its inferred northward extension. In response to rapid subsidence (reflecting possible southward subduction zone retreat) clastic sediment sources to the north then submerged while clastic sediment was instead mainly supplied from the South Neotethyan suture zone to the east and northeast in southern Turkey. Reflecting diachronous collision, deep-water deposition persisted in the easternmost Mediterranean basin further west until this was terminated in northern Cyprus by thrusting/folding during latest Miocene–earliest Pliocene. Quaternary collision-related uplift ensued. Similar sedimentary development is to be expected in collisional settings elsewhere (e.g. Tethyan closure in the Himalayas; Iapetus closure in the Appalachians).