METHODS

Standard nannofossil smear slide techniques were used to prepare samples. Unprocessed sediment was smeared on a glass coverslip, dried, and then mounted on a glass slide using Norland optical adhesive 61 mounting media. The nannofossil biostratigraphy presented here is based on the examination of each sample using a Zeiss Photomicroscope III under 625x - 1560x magnification, using phase-contrast, plain, and cross-polarized light. Several traverses were made, and relative abundance of individual species, overall abundance of nannofossils, and assemblage preservation were recorded for each sample using BugWin software (BugWare, Inc.).

Range charts presented herein as Tables T1 ad T2 were created using these measurements. Individual species abundance are represented by the following abbreviations:

V = very abundant (more than 100 specimens per 10 fields of view [FOV]).

A = abundant (11-100 specimens per 10 FOV).

C = common (6-10 specimen per 10 FOV).

F = few (1-5 specimen per 10 FOV).

R = rare (1 specimen per >10 FOV).

The same definitions were used for estimations of total abundance of nannofossils within each sample, with the additional definition of B (barren of nannofossils). Preservation of the calcareous nannofossil assemblage was determined as follows:

G = good (individual specimens exhibit little or no dissolution or overgrowth, diagnostic characteristics are preserved, and nearly all of the specimens can be identified).

M = moderate (individual specimens show evidence of dissolution or overgrowth, some specimens cannot be identified to the species level).

P = poor (individual specimens exhibit considerable dissolution or overgrowth, many specimens cannot be identified to the species level).

Calcareous nannofossil species considered in this paper are listed in "Appendix," where they are arranged alphabetically by generic epithet. Bibliographic references for these taxa can be found in Perch-Nielsen (1985) and Bown (1998). Key marker species were photographed (Plate P1).