Variations in carbonate-evaporite shoreline and ramp facies trends: Middle Miocene Fatha Formation, Kurdistan Region, NE Iraq

A sedimentological investigation of Miocene deposits at the periphery Zagros foreland basin , Kurdistan Region, NE Iraq, reveals a cyclical arrangement carbonate-evaporite ramp facies . The study aims to provide rare insight into lateral variability microfacies and environments such systems' inner shoreline Between 10 40 depositional cycles are preserved, separated by flooding surface, recording an overall basinward progradation In each cycle, shallowing-upward trend from lower-energy calcareous mudstone mudstone-wackestone carbonate base higher-energy packstone-grainstone-rudstone or low-energy algal mat/stromatolitic above is evident. Evaporite supratidal sabkha origin cap deposit. Red clastic sediments that advanced south-westward adjacent hinterland overlie evaporite surface return mudstones mark start next cycle. Outcrop thin-section analysis cycle shoaling-up inner-ramp with varied environmental settings developed under range hydrodynamic conditions. Microfacies indicates these included normal marine salinity open lagoons hypersaline lagoons, restricted shallow sand shoals, intertidal flats, ponds, coastal alluvial plain channelised palaeosols changes toward top succession in relative rate siliciclastic supply markedly increased, whereas production decreased. Progradation migration through time caused vertical thickness variations over succession. Repeated sea-level changes, associated climate, sediment hinterlands during collision Arabian Iranian plates, combined variable accommodation generation, inferred have controlled preserved cyclicity • Basin Fatha Formation carbonate-evaporite-red bed vary laterally. Carbonates shoal upwards high energy low energy, e.g. stromatolitic, facies. Inner clastics evaporites; flux increases upward. Controls: Varying Middle sea level, erosion accommodation.