Miocene burrows of the Ghost Crab Ocypode and their environmental significance (Mykolaiv Sands, Fore-Carpathian Basin, Ukraine)

The huge lithosome of the Middle Miocene (Early Badenian) Mykolaiv Sands, developed at the external margin of the Fore-Carpathian Basin in western Ukraine, is recognized to represent a shallowing-up sequence. Special attention is paid to burrows of the Ghost Crab Ocypode which are pantropical in present-day littoral habitats. In the Stratyn section, burrows of this type become a crucial tool in the interpretation of basin bathymetry, which starts from distal offshore depths, through the foreshore, to the backshore where the Ocypode burrows record a temporary break in sedimentation. Lithification of the sand layers and the Ocypode burrows subsequently progressed in beachrock mode. The Stratyn section demonstrates that the development of submerged shoals and/or emergent parts, throughout the huge mass of the Mykolaiv Sands, is probably responsible for their great variation in thickness in western Ukraine, which has long proved difficult to explain.