Alveolinids at the Middle-Upper Eocene boundary in northeastern Italy (Veneto, Colli Berici, Vicenza)

Citation
D. Bassi et Cl. Broglio, Alveolinids at the Middle-Upper Eocene boundary in northeastern Italy (Veneto, Colli Berici, Vicenza), J FORAMIN R, 29(3), 1999, pp. 222-235
Citations number
63
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF FORAMINIFERAL RESEARCH
ISSN journal
00961191 → ACNP
Volume
29
Issue
3
Year of publication
1999
Pages
222 - 235
Database
ISI
SICI code
0096-1191(199907)29:3<222:AATMEB>2.0.ZU;2-7
Abstract
The Middle and Upper Eocene successions of the Colli Berici (Veneto, northe astern Italy) have been studied since the beginning of the nineteenth centu ry in order to describe the large, benthic foraminiferal-rich assemblages, The Bartonian-Priabonian exposures in the southeastern part of the Colli Be rici (Mossano) have been the proposed "parastratotype" for the Priabonian s tage. The classic Mossano section and two additional sections outcropping i n this area, all spanning the Calcari Nummulitici (Middle Eocene)-Marne di Priabona (Late Eocene) formations, provided us with new biostratigraphic da ta about two alveolinid species, Borelis vonderschmitti (Schweighauser) has so far been recorded in the Colli Berici (type locality Cava Zengele) with in the Bartonian part of the Calcari Nummulitici formation, and possibly in the Priabonian of Italy and Slovenia, This taxon is herein described from Mossano, and the associated larger foraminifera (Nummulites biedai) confide ntly establish the age of these beds as Late Bartonian (SBZ 18), enabling t he stratigraphic distribution of B. vonderschmitti to be extended to the ba se of SBZ 18.A new species of Glomalveolina Hottinger 1960, G. ungaroi n. s p. is formally described herein; this taxon differs from the other Middle E ocene representatives of this genus by having a lower elongation index and a larger proloculus. It is so far known only from the Late Bartonian of the Colli Berici, and represents one of the smallest alveolinids following the peak diversity of the Lutetian, Both species occur in shallow water calcar enites, and are the only representatives of the Alveolinidae in Upper Barto nian carbonate units of the Colli Berici.