Comment on “Holocene sedimentation in the southwestern Black Sea: Interplay between riverine supply, coastal eddies of the Rim Current, surface and internal waves, and saline underflow through the Strait of Bosphorus” by O. Ankindinova, A. E. Aksu, R. N. Hiscott [Marine Geology, 420 (2020) 106092]

Abstract

Ankindinova et al. (2020) describe a series of hydrological events that have led to sedimentation and stratigraphic variations in the gradual sinking of the Black Sea shelf during the Holocene. A key aspect of the study is the attempt to provide a reliable stratigraphic basis for proving of a transgression in the basin throughout the Holocene. However, the conclusions of this approach run counter to the stratigraphic rules: redeposition and significant hiatus in the transgressive phase change of depth of sediment core location (M05-03P) – principle of superposition; merging of transgressive and regressive deposits into a common stratigraphic unit (contradicts the sequential stratigraphy). For this reason, the stability of the conclusion of Ankindinova et al. (2020) for the totally transgressive Holocene development of the Black Sea is doubtful. In addition, the study is based on the interpretation that the increase in the 87Sr /86Sr ratio is solely dependent on ocean water inflow, which is not always correct for enclosed and semi-enclosed basins.