Evolution of two overlapping sand-rich clastic submarine fans in the Lower Miocene Adana Basin, southern Turkey: Contribution from a new palaeocurrent analysis

Abstract

A complete longitudinal profile from the continental shelf break to the basin floor includes a significant and well-exposed turbidite system at the northern edge of the Adana Basin, one of a series of foreland basins in southern Turkey. This study focused on the evolutionary interpretation of 2 coeval submarine fans, the Western Fan and the Eastern Fan, in the Upper Burdigalian-Lower Serravallian Cingoz Formation. The Western Fan was fed by a single major canyonised feeder from the west, and the Eastern Fan was fed by multiple feeder channels to the north. The Western Fan originated as a confined system with 2 depositional styles of frontal splay development: a) elongate tongue-shaped bodies, extending at least 15 km downdip, and b) radial, lobe-shaped bodies. The Eastern Fan has a more complex internal structure than the Western Fan. In this study, a total of around 952 palaeocurrent measurements were obtained from specified sedimentary structures in exposures from 42 localities. These data showed that a portion of the Eastern Fan was deposited on top of the eastern extension of the Western Fan. Subsequently, the buried Western Fan acted as a submarine topographic high during the deposition of the final phases of the Eastern Fan, changing the direction of the currents forming the lobes of the final phase from the southwest to the east. The submarine topography had a crucial effect on the development of the lobe elements and evolution of these 2 fans of the Cingoz Formation. The information learned from the study of these 2 fans can be useful to understand their counterparts elsewhere.