Onshore-Offshore Coastal Lithofacies of Polis Basin, NW Cyprus

Lester C. Ward

The Polis basin, northwest Cyprus, is located between the Akamas Peninsula and the main Troodos ophiolite massif. The basin contains sediments of Miocene-Holocene age and allows detailed study of a range of onshore-offshore coastal lithofacies which represent potential reservoirs. Coastal sediments of Messinian age characterized by algal mats and fluvial channel fill are found in the basin. Following very late Miocene rifting and Pliocene transgression, steep, narrow, faulted coastlines were produced, and several coastal facies were generated. These include coastal alluvial fans, offshore reefs, and tectonically generated cliff deposits as olistolith blocks. The steep, faulted coastline generated fan-delta deposits in early Pliocene time, superseded during late Pliocene r gression by carbonate fan deltas. Offshore coastal lithofacies include storm-generated deposits, consisting of rip-up clasts and hummocky cross-stratification in sand-silt sequences, and mass-flow and channelized conglomerates and debris flows in this tectonically active basin. Shoreline sands are dominated by long-shore drift which generated longitudinal sandbars and offshore gravel bars. Pleistocene-age deposits show several suites of coastal deposits, formed in response to oscillations in Pleistocene sea level. These include beach deposits demonstrating beach-crest and planar bimodal back-beach deposits, together with coastal lagoons transected by cross-bedded fluvial conglomerate deposits. In addition, lowstands produced large channelized braided fluvial deposits which formed part of a broad coastal plain. Certain Pleistocene channels are deformed by continuing synsedimentary tectonic activity.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.