A fluvial record of active fault-propagation folding, Salsomaggiore anticline, northern Apennines, Italy
The Salsomaggiore anticline in the northern Apennines is an actively growing fault-propagation fold that is flanked by a suite of early Middle Pleistocene (~0.8 Ma) to Recent fluvial terraces, which reveal a foreland-migrating wave of coupled incision and aggradation, interpreted to reflect the response of a fluvial system to progressive vertical and lateral fold-propagation. This ~10km-wavelength fold resides ~25 km hinterward of the modern structural front and exhibits a complex growth history extending back to at least the middle Miocene. Langhian-Messinian, marginal- to deep-marine clastics are folded about a NW-SE trending axis, record the majority of fold growth, and are superimposed by the Ligurian nappe and Pliocene-Recent deep-marine, marginal-marine, and fluvial strata with shallowing upward dips. Active growth is documented by fluvial terraces, recent seismicity, deflected stream channels, first-order stream gradients, and long-profile modeling. › Continue reading