A 400-km-long piggyback basin (upper Aptian-lower Cenomanian) in the Eastern Alps

The Late Aptian to Early Cenomanian Tannheim-Losenstein basin constitutes an early, deep-marine piggyback trough which formed on the Cretaceous orogenic wedge of the Eastern Alps. The narrow basin extended over more than 400 km from the western part of the Northern Calcareous Alps into the Western Carpathians (Slovakia), as suggested by similarities in stratigraphy- e.g. the common coarsening upward succession of marls, sandstones, and conglomerates and by similarities in timing of deformation and the uniform composition, e.g. similar heavy mineral assemblages. The coarsening-upward succession resulted from the progradation of a coarse-grained slope apron into a hemipelagic basin. The composition of detrital material constitutes evidence for a uniform source area to the north, along the entire length of the basin, comprising continental basement, Mesozoic sediments and remnants of ophiolites. The basin formation marked the onset of compression along the northern Austroalpine plate boundary.