Tectonic Controls on Miocene Reefs and Related Carbonate Facies in Cyprus
Edward J. Follows, Alastair H. F. Robertson, Terence P. Scoffin, 1996. "Tectonic Controls on Miocene Reefs and Related Carbonate Facies in Cyprus", Models for Carbonate Stratigraphy from Miocene Reef Complexes of Mediterranean Regions, Evan K. Franseen, Mateu Esteban, William C. Ward, Jean-Marie Rouchy
Download citation file:
Reefs of Early Miocene (Aquitanian/Burdigalian) and Late Miocene (Tortonian) age are exposed in Cyprus, mainly around the periphery of the Troodos ophiolitic massif. Reef growth followed early Tertiary deep-water sedimentation and localized tectonic uplift. The Aquitanian/Burdigalian Terra Member formed on isolated, stable basement highs in southeast and west Cyprus. Up to 500 m- by 80 m-sized, faunally diverse patch reefs grew in relatively shallow, calm seas. Fore-reef and basinal facies are exposed in western Cyprus. Reefs of the Tortonian Koronia Member reflect local tectonic settings. Those in southern Cyprus developed on linear highs, related to earlier crustal compression. These reefs are preserved almost entirely as channelised talus in adjacent basins. Around the western and, particularly the northern margins of the Troodos ophiolite, reef growth was influenced by active crustal extension. Patch reefs in the north formed on uplifting fault blocks and large volumes of talus were shed down steep slopes into basins to the north. In west Cyprus, the reefs grew on both flanks of a gradually subsiding graben, with local preservation of back-reef facies. The Late Miocene reefs were dominated by Porites, first largely domal, then mainly as sheet-like encrustations. Growth of both the Early and Late Miocene reefs was preceded by erosion and was then followed by transgression, associated with a relative sea-level rise. Reef growth was finally brought to an end by Messinian desiccation of the Mediterranean. The reefs were cemented by Mg - calcite and botryoidal aragonite during and shortly after growth. Subsequently, during exposure to meteoric and brackish waters, the fabric of the reef was modified by dissolution, neomorphism, calcite spar and locally gypsum cementation. Uplift and extensional faulting caused fracturing of the, by then, brittle reefs (Terra Member) and fissures were locally enlarged by karst-forming solutions. A marine transgression in the ensuing Early Pliocene time then filled the fissures with fine-grained carbonate sediments, which were prone to mixing-zone dolomitization.
Figures & Tables
Miocene carbonates are intensively explored and locally exploited for hydrocarbons in parts of the Mediterranean regions. The outcrop models presented in this publication provide excellent analogs for the highly productive Miocene carbonates from Iran, Iraq and Gulf of Suez and for smaller reservoirs in other localities. Lessons learned in the outcrops of the Mediterranean regions are applicable as well to Miocene carbonate reservoirs. The Miocene outcrops in Mediterranean regions can serve as models for the relationships between carbonate reservoirs, pre-evaporitic basinal sediments, and overlying evaporites. Additionally, the Miocene carbonate rocks exposed in the Mediterranean regions serve as important analogs for ancient carbonate-rimmed basins with or without basinal evaporites.