Upper Pliocene bivalve shell concentrations from the Lower Chelif basin (NW Algeria): Systematics, sedimentologic and taphonomic framework

First record of blister pearls in the oyster Hyotissa hyotis (Linné, 1758) from Pliocene deposits at Sidi Brahim, Lower Chelif Basin (north-west Algeria)

“…1, 2) which surround the north-eastern side of Lower Chelif Basin, about 1.5 km south of the city of Sidi Ali. This outcrop has been studied by many authors during many decades (Anderson, 1936;Atif et al, 2008;Satour, 2012;Satour et al, 2013;Bendella et al, 2021;Benyoucef et al, 2021). The Neogene series is complete in the Lower Chelif Basin and ranges from the Burdigalian to the Pliocene (Benyoucef et al, 2021).…”

“…This outcrop has been studied by many authors during many decades (Anderson, 1936;Atif et al, 2008;Satour, 2012;Satour et al, 2013;Bendella et al, 2021;Benyoucef et al, 2021). The Neogene series is complete in the Lower Chelif Basin and ranges from the Burdigalian to the Pliocene (Benyoucef et al, 2021). The Neogene sediments rest with diastrophic unconformity on an allochthonous bedrock of Cretaceous to Oligocene age (Benyoucef et al, 2021).…”

“…The Neogene series is complete in the Lower Chelif Basin and ranges from the Burdigalian to the Pliocene (Benyoucef et al, 2021). The Neogene sediments rest with diastrophic unconformity on an allochthonous bedrock of Cretaceous to Oligocene age (Benyoucef et al, 2021). The Neogene series is divided into Miocene and Pliocene sedimentary cycles (Benyoucef et al, 2021).…”

“…The Neogene sediments rest with diastrophic unconformity on an allochthonous bedrock of Cretaceous to Oligocene age (Benyoucef et al, 2021). The Neogene series is divided into Miocene and Pliocene sedimentary cycles (Benyoucef et al, 2021). The Miocene began with a Burdigalian transgressive phase over the Cretaceous substratum, and is represented by conglomerates, sandstones and dark marls commonly called "marnes bleues" ('blue marls') .…”

“…The Miocene began with a Burdigalian transgressive phase over the Cretaceous substratum, and is represented by conglomerates, sandstones and dark marls commonly called "marnes bleues" ('blue marls') . Another transgressive phase took place during the Late Miocene, followed by regression (Messinian salinity crisis) (Benyoucef et al, 2021). An abrupt marine transgression has been noted at the start of the Pliocene, and this is terminated by the Astian regression (Benyoucef et al, 2021).…”