Sedimentology and depositional environment of the Late Eocene marine siliciclastic to evaporite transition in the Sivas Basin (Turkey)

The E-W oriented Sivas foreland basin in Turkey recorded a salinity crisis during the Late Eocene resulting evaporite accumulations thick enough to trigger intense halokinesis Oligo-Miocene. is studied thanks three sedimentological sections crossing transition from last marine deposits (Bözbel Formation) overlying evaporitic facies (Tuzhisar preserved halokinetic deformations. top of Bözbel Formation presents flood-generated hyperpycnites developed pro-delta delta front settings. In central part basin, such become increasingly sediment-starved with azoic calcareous interlayered organic-rich shales. Such are ultimately capped by gypsiferous turbiditic lobe deposits. Southward, foredeep was partly isolated domain due propagation an anticline. There, basal siliciclastic turbidites gypsum-rich and 45 m-thick mass-transport deposit enclosing olistoliths gypsum ophiolitic rocks. gravity collapse evolve upward same lobes observed northward. Both transitional record progressive confinement sea, likely northward fold-and-thrust belt located farther south. evaporites started precipitate piggy-back basins, along highs belt, before being reworked gravitationally north, producing high low density turbidites. Finally, north south, extensively covered >100 m thick, chaotic, prismatic mass hydration anhydrite grains left as residual phase after leaching significant amount halite. latter formed hypersaline marine-fed have lately allowed mini-basin salt tectonics Oligo-Miocene times.