Smear slides were made from unprocessed sediments and examined with a light microscope at a magnification of 1000x. For the critical middle Miocene interval, a nannofossil range chart was developed (Table T1). The abundance of selected nannofossil taxa on each slide was recorded for this table using the following criteria: F = few, 1 specimen per 11–50 fields of view; R = rare, 1 specimen per 51–200 fields of view; B = barren. For preservation of nannofossil assemblages, P = poor, strong etching and/or overgrowth.
The bibliographic references for the species used in this study can be found in Perch-Nielsen (1985). Numerical ages discussed in this report refer to the timescale of Berggren et al. (1995).