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.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Analysis of trace fossil abundance and diversity in the Oligocene to Miocene foredeep and piggyback basins of the Tuscan-Romagna-Umbrian Apennines allows us to recognize five ichnocoenoses. The deposits reflect sedimentary environments from slope to basin plain, whose sedimentation was directly controlled by synsedimentary tectonics: attached fan lobes and channels, lobe- and channel-fringes, overbank-fringes of intrabasinal highs, distal detached lobes of basin plain and slope-proximal interfans. The graphoglyptid: non-graphoglyptid ratio has been considered as the chief factor in the study of ichnologic material from Falterona-Cervarola-Trasimeno, Marnosoarenacea and Marne di Vicchio-Verghereto stratigraphic units. The study shows that there is an increase in ichnodiversity and ichnodensity of graphoglyptids, which are typical mainly in detached lobes of basin plain and overbank-levee deposits whose background ichnofauna also shows better preservation.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.