COASTAL PALEOENVIRONMENT: A LOWER DEVONIAN (EMSIAN) LAND-SEA TRANSITION SOUTH OF THE OLD RED CONTINENT (MOSEL SYNCLINE, RHEINISCHES SCHIEFERGEBIRGE, GERMANY)
In the section two distinct, fossiliferous units contain abundant terrestrial plant remains and a diverse fauna. Physical sedimentary structures prevail throughout, whereas bioturbation is mostly restricted to the fossiliferous units. Erosional surfaces mainly separate the beds. Aside from ripple cross-stratification and parallel bedding, longitudinal cross-bedding is most common. Channel-fills are less frequent. Scour-and-fill structures exhibit marked disconformities of irregular shape on a smaller scale. Mud pebble layers at the base of laterally prograding cross-bedded layers, scour-and-fill structures, and drainage rills characterize the upper part of the section. More sporadically, desiccation cracks, wind-induced striations, and water-level marks occur.
The sedimentary structures and the paleontological information indicate a marine to brackish environment with frequent emergence in an intertidal setting along the coastal region (including lagoons and estuaries) of a presumed Hunsrück Island/Archipelago. Terrestrial plant remains indicate a position at the land/sea interface characterized by a complex configuration of different environments. Thick packages of plant material may have been derived during meteorological events such as hurricanes.