Detection of detached forced-regressive nearshore wedges: a case study from the central-southern Siena Basin (Northern Apennines, Italy)

摘要: The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one the hottest topics sequence stratigraphic analysis due their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased impermeable clay, thus presenting a good potential traps for fluids. This paper focuses on Pliocene deposits cropping out central-southern sector Siena Basin (Tuscany, Italy), post-collisional basin Northern Apennines. exposed sedimentary succession was investigated through detailed sedimentological approach, integrated by biostratigraphic analyses, aimed at better characterization infilling history this basin. Specifically, study revealed occurrence repeated facies shifts that allowed identification two depositional sequences. detail, thick sand-rich body far from margins, previously turbiditic lobe, has been reinterpreted setting during fall sea level. totally offshore lack physical connection with related HST deposits, it be forced-regressive wedge. present work led recognition some features typical falling stage systems tract (e.g. presence intrabasinal recycled materials, evidence pre-existing fluvial network subsequently eroded) can provide useful clues core studies poorly settings.