The Paleogene larger foraminifera (LF) are widespread in carbonate sediments from different parts of the northern Italy. They are particularly abundant and well known from the Veneto area (Berici and Lessini Mountains), where there are several “classic” localities. Conversely, on the northern side of the northern Apennines, the Paleogene formations are mainly terrigenous turbidites, substantially different from the carbonate platforms of the Southern Alps.Nevertheless, there are in literature some scanty records of LF even in some flyschoid formations from the Emilian side of the northern Apennines. The presence of LF has been usually neglected, both for their rarity and for the clear redeposition of the tests out from the environment of life.Starting from the known occurrences, we restudied the Paleogene LF from three formations, namely the Loiano Formation, the Montepastore Formation (formerly known as Coscogno Flysch or Coscogno Limestones), and the Monte Sporno Flysch.The LF identified showed usually the same age in the same samples, so the assemblages are substantially contemporary. Moreover, the ages of the assemblages are consistent with the ages determined with different tools.The assemblage with Nummulites anomalus, N. beaumonti, N. incrassatus, N. problematicus, N. variolarius, Discocyclina radians radians, Orbitoclypeus varians varians, Asterocyclina stella stella, Asterocyclina stellata stellaris allow to assign a Bartonian age (SBZ 18) to the upper part of the arenaceous member of the Loiano Fm. Its lower part, with Nummulites alponensis, N. maximus, N. millecaput, N. variolarius, Operculina parva, Discocyclina radians radians, Orbitoclypeus douvillei chudeaui, Asterocyclina stella stella, Asterocyclina stellata stellaris is probably of Middle-Late Lutetian age (SBZ 15-16), even if some reworking is here probable. The assemblages collected from the Montepastore Fm. and from the Monte Sporno Flysch contain Alveolina cf. ellipsoidalis, A. moussoulensis, Glomalveolina cf. pilula, Orbitolites biplanus, Nummulites praecursor, Ranikothalia sp., Discocyclina archiaci bakhchisaraiensis. They are both attributed to the Lower-Middle Ilerdian (SBZ 6-7, basal Eocene). It is worthy noting that some authors suggested a strict correlation between these formations.The provenance of the bioclasts is still matter of speculation, given the complete absence of carbonate platform sediments in the surroundings.
|Data di pubblicazione:||2007|
|Autori:||Papazzoni C.A.; Zoboli P.|
|Titolo:||Resedimented Paleogene larger Foraminifera from the northern Apennines (Modena, Bologna, and Parma Provinces).|
|Appare nelle tipologie:||Abstract in Atti di Convegno|
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