Range charts showing the distribution of all species observed are presented in Tables T1, T2, and T3. Zonal and other key datums for the three sites are compiled in Tables T4, T5, and T6 using meters composite depth (mcd) from Bralower, Premoli Silva, Malone, et al. (2002) and revised meters composite depth (rmcd) from Westerfeld and Röhl (this volume).
Calcareous nannofossil preservation is generally moderate in the Paleocene to lower Oligocene section at Sites 1209, 1210, and 1211. Most samples show signs of slight etching and moderate overgrowth. Overgrowth has masked whole specimens, making it difficult to distinguish consistently among species of Nannotetrina, for example, and to consistently interpret the ray form of discoasters. Etching, for example, often removes the central area of Toweius. A few samples distributed randomly through the sections have good preservation. In general, preservation deteriorates from the Paleocene to the Eocene and nannofossils in a number of Eocene samples are marked by moderate to high amounts of etching as a result of dissolution. There is no systematic increase in overgrowth or dissolution with depth; thus, preservation appears to be related to alteration at or near the seafloor.
The standard zonation of Bukry (1973, 1975), emended by Okada and Bukry (1980), was developed in low-latitude oceanic sections. Hence, this scheme is primarily applied here. The zonation of Martini (1971), on the other hand, was established in land sequences largely from the continents. Generally, many of the zones of both schemes and the subzones of Okada and Bukry (1980) could be determined at Sites 1209, 1210, and 1211 with a fair amount of confidence (Tables T4, T5, T6). However, a number of these units could not be determined due to taxonomic difficulties or paucity of key species. For example, the base of Zone CP7 could not be determined because of the rarity of Discoaster nobilis. The base of Zone CP3 was difficult to determine with precision as a result of the rarity of Ellipsolithus macellus near the onset of its range. In addition, the base of Zone CP14 (Subzone CP14a) was difficult to determine because of the sporadic distribution of Reticulofenestra umbilicus near the base of its range. Finally, the base of Subzone CP16b, defined by the base of the acme of Ericsonia subdisticha, is also difficult to determine precisely, as this species is rarely abundant in samples investigated. The significance of the zonal markers and other datums that have potential as zonal markers will be discussed in detail in Bralower (unpubl. data).
Nannofossil biostratigraphy suggests extremely slow sedimentation or unconformities at all sites. At Sites 1209 and 1210, the uppermost Eocene and lowermost Oligocene interval is extremely condensed, with multiple datums concentrated within a few meters (~137–141 mcd at both sites; Tables T1, T2, T4, T5). The upper part of the middle Eocene (Subzones CP13b–CP14a; ~98 mcd) at Site 1211 appears to be condensed (Tables T3, T6). In addition, the lowermost Eocene (Zone CP9) at Sites 1209 (~208 mcd), 1210 (~201 mcd), and 1211 (~136 mcd) appears to be highly condensed. More detailed investigation is required to determine if unconformities are present in these intervals. Reworked nannofossils have not been observed, except in the upper Eocene where markers are observed significantly above the termination of their ranges (Tables T1, T2, T3).