While the sedimentological development of the Quaternary in the northern Upper Rhine Graben is well researched, there is a lack of in-depth investigations for the underlying Iffezheim Formation. To close this gap, detailed sedimentological and sequence stratigraphic investigations were carried out on an approximately 220 m long Pliocene core section of the Riedstadt-Erfelden research borehole drilled in 2020 and 2021, which is also the northernmost borehole of its kind in the Upper Rhine Graben to date. This work presents insights into sedimentary facies of the Upper Pliocene Iffezheim Formation and investigates the cyclicity in sedimentation dynamics based on facies analysis including petrophysical measurements (total gamma ray logging, spectral gamma ray logging and magnetic susceptibility measurements). Relatively thick successions of channel sediments and pedogenetically influenced floodplain deposits accompanied by abundant crevasse splays indicate an anastomosing fluvial style for the river Rhine system during the Upper Pliocene. By analyzing the cyclicity, three orders of magnitude of cycles could be identified, each consisting of predominantly stacking patterns of base-level-rise half-cycles with some intermediate base-level-fall half-cycles. In addition to a detailed facies model of the Rhine system in the Upper Pliocene of the central, northern Upper Rhine Graben, this work thus also offers an approach to correlate further sections of the Iffezheim Formation basin-wide. Based on this, the knowledge gained can be used stratigraphically in a wider region and context.