Sequence response to syndepositional regional uplift: insights from high-resolution sequence stratigraphy of late Early Pleistocene strata, Periadriatic Basin, central Italy.

This paper deals with the depositional sequences that occur within the uppermost part of the Plio–PleistocenePeriadriaticbasin fill in the southern Marche region, centralItaly. The succession is an EarlyPleistocene, easterly dipping clastic wedge showing an overall shallowing trend from slope clays to shallow-marine and non-marine deposits comprising two major sequences, namely Qmb and Qmc. Analysis has provided new insights into: (i) the nature of sedimentary facies and facies associations occurring within the upper part of Qmb and Qmc; (ii) the gradual contact within Qmb between regressive littoral deposits (RLD) and underlying deep-marine blue clays; (iii) the composite origin of the Emilian surface, which is a widespread erosional unconformity separating Qmb from Qmc; (iv) the cyclothemic pattern of Qmc, composed of downstepping, small-scale depositional sequences; (v) the role played by synsedimentary uplift on the stacking pattern of small-scale sequences and their internal architecture.Up to three small-scale depositional sequences have been recognised within Qmc. They are up to 50 m thick and defined by previously unrecorded. High-frequency sequences display a distinctive stacking pattern and form a tectonically induced forced regressive sequence set underlain by a composite, tectonically enhanced regressive surface of marine erosion formed by the lateral connection of lower-rank sequence boundaries.