Integrated analysis of the Neogene–Quaternary Valdera‐Volterra Basin (Northern Apennines). Evidence for composite development of hinterland basins

• Published in: Basin research 2024-09, Vol.36 (5), p.n/a
• Main Authors: Poneti, Giovanni, Benvenuti, Marco, Scarselli, Nicola, Craig, Jonathan, Sani, Federico
• Format: Article
• Language: English
• Subjects: Anticlines; Basins; Data analysis; Deformation; Depth profiling; Evolution; Geological faults; Geology; Geophysical data; Geophysics; Gravity data; Hinterland basins; Messinian; Miocene; Neogene; Northern Apennines; Pleistocene; Polyphase tectono‐sedimentary evolution; Quaternary; Sedimentary basins; Sediments; Seismic profiles; Seismic reflection profiles; Seismic surveys; Stratigraphy; Synclines; Tectonics; Two dimensional analysis
• ISSN: 0950-091X; 1365-2117
• DOI: 10.1111/bre.12897

The Neogene and Quaternary hinterland basins of the Northern Apennine have been the subject of different tectonic interpretations. Several studies considered these basins as the result of polyphase normal faulting framed in a continuous crustal extensional regime since the middle Miocene. On the contrary, geophysical and geological studies provided evidence of the important role played by out‐of‐sequence thrusts and backthrusts in the evolution of these basins during a prolongated and intense period of shortening. Here we present an integrated analysis of 2D stacked seismic reflection profiles, stratigraphic and geophysical data from deep exploration wells, gravity data, and published geological and biostratigraphic data for the Valdera‐Volterra basin (central Tuscany, Italy). The results support a polyphase and composite evolution of the basin, subdivided into three main phases. During the late Tortonian–Zanclean, the growth of major thrust‐related anticlines controlled the evolution of the sedimentary basin. The growth of a syncline determined the creation of accommodation space for the sediments. This main compressional deformation occurred during the Messinian and ended during the Late Zanclean. NE migration of the depocentre during the Early Zanclean was identified, likely possibly due to a differential activity growth between the bordering anticlines. During the Piacenzian, an extensional phase has been recognised, superposed to the previous compressive phase. During the Latest Piacenzian–Early Pleistocene (?), a final compressional phase took place resulting in the positive inversion of the Piacenzian WSW dipping main border fault. Reconstruction of the polyphase tectono‐stratigraphic evolution of the Neogene‐Quaternary Valdera‐Volterra Basin, one of the largest hinterland basin of the Northern Apennines, through the study of 2D seismic sections integrated with published and unpublished geophysical and stratigraphic data from deep boreholes and surface palaeontological samples.