Report 2007, 2008 and 2009 of the Lutetian/Bartonian Boundary Working Group:

The work of the Lutetian-Bartonian Boundary Working Group during 2007, 2008 and has continued its focus on the base of magnetic polarity chron 19N as a guide horizon for the base of the Bartonian. For the base of chron 19N to be a useful guide horizon for the base of the Bartonian Stage, its correlation potential must be demonstrated. The working group has continued to focus field and laboratory studies on the correlation potential of this horizon.
The section along the Contessa Highway near Gubbio, Italy remains the primary candidate for a GSSP. Historically, this section has been the focus of important biostratigraphic studies of planktonic foraminifera and calcareous nannofossils. The Contessa Highway section also contains an excellent magnetic stratigraphy record in the Paleocene and Eocene.
Results of a high-resolution geomagnetic, geochemical, and biostratigraphic study of the Contessa Highway section were published during 2007 (Jovane et al. 2007).
Studies of the Barton Clay at Alum Bay and Barton-on-Sea, U.K: Further study of the Barton Clay at Barton-on-Sea and at Alum Bay on the Isle of Wight is desirable to clarify the magnetic stratigraphy of the traditional “unit stratotype” of the Bartonian. Magnetic stratigraphy has been completed on the underlying Bracklesham beds on the Isle of Wight and correlated with polarity chronozones through the use of calcareous nannofossils. To date, no paleomagnetic data has been collected from the Barton Clay. Results from this work will enhance our understanding of the chronostratigraphy of the type Bartonian and enable better decision-making when selecting a final GSSP.
Future Work: Identifying reliable biostratigraphic horizons to serve as additional guides to the base of the Bartonian remains a challenge. Several important biostratigraphic events occur near, but not precisely at, this horizon and may assist with correlation. Several of these events are listed in Fluegeman (2007).
The working group hopes to complete its work and propose a GSSP for the Bartonian by 2011.
References: Fluegeman, R. H., 2007, Unresolved issues in Cenozoic chronostratigraphy. Stratigraphy, vol. 4, p. 109-116.
Jovane, L., Florindo, F., Coccioni, R., Dinarès-Turell, J., Marsili, S., Monechi, S., Roberts, A. P., and Sprovieri, M., 2007, The middle Eocene climatic optimum event in the Contessa Highway section, Umbrian Apennines, Italy: Geological Society of America bulletin, vol. 119, p.413-427; doi: 10.1130/B25917.1.

Report by Richard H. Fluegeman, Chairman