Annual Report 2006 of the Bartonian/Priabonian Boundary Stratotype Working Group

Studies in 2006 focused on the Alano di Piave section (Veneto region, NE Italy), the potential candidate for defining the GSSP of Middle/Upper Eocene, equated to the base of the Priabonian Stage. The Alano section, continuously exposed along the banks of the Calcino Creek, consists of 120-130 m-thick gray marls of the Scaglia Cinerea Formation deposited at bathyal depth. It is easily accessible, is unaffected by structural deformation, is rich in calcareous plankton and contains the critical interval for defining the GSSP of the Priabonian. Calcareous plankton (nannofossils and foraminifera) high-resolution biostratigraphies have been completed and correlated to magnetostratigraphy across the critical interval.
The main bioevent in planktonic foraminifera, the extinction of the large acarininids (e.g. A. praetopilensis, A. rohri) and of Morozovelloides crassatus (formerly Morozovella crassata) just above, correlates with magnetic chron C17.3n falling in the same position as detected at ODP Site 1052 (Blake Nose, W Atlantic). This is supported by quantitative analysis on calcareous nannofossil distribution from both locations: across the studied interval at Alano and Site 1052 calcareous nannofossils show similar abundance patterns and in the same position with respect to the main planktonic foraminiferal event and magnetic chrons. Magnetic measurements of the Alano section have been extended below and above the critical interval and currently cover almost the whole section. Stable isotope analysis, dinocyst biostratigraphical and benthic foraminiferal studies are in progress. A paper on integrated calcareous plankton biostratigraphy calibrated to magnetostratigraphy is in preparation.
A synthesis of the available data was presented at the international meeting on “Climate and Biota of the early Paleogene” held in Bilbao in June 2006.
Reference
Rio D., Premoli Silva I., Agnini C., Brinkhuis H., Fornaciari E., Giusberti L., Grandesso P., Lanci L., Luciani V., Muttoni G., Stefani C., Villa I., The Alano di Piave section (Venetian Southern Alps, NE Italy). A potential GSSP of the Priabonian Stage (Upper Eocene). International Conference on “Climate and Biota of the early Paleogene”Abstract Volume, p. 109. ISBN 84-689-8939-8.

Report by Isabella Premoli Silva, Chairwoman.