The red clays and radiolarian clays of Site 1217 are mostly barren of calcareous microfossils with the exception of a few short intervals (Fig. F8). The fossil content of the upper part of the sediment sequence is limited to ichthyoliths and occasional concentrations of agglutinated benthic foraminifers. The underlying radiolarian clays, whose top is at ~26.3 mbsf in Section 199-1217A-4H-2, contain radiolarian assemblages indicative of a late Eocene-middle Eocene age (RP18 to RP14). A late Eocene-middle Eocene age for the top of the radiolarian clay sequence is supported by a few samples containing calcareous nannofossils and calcareous benthic foraminifers. A 1.13-m-thick sequence of nannofossil chalk in Core 199-1217A-16X (128.1-129.2 mbsf) contains a diverse and moderately well preserved assemblage of nannofossils, planktonic foraminifers, and benthic foraminifers representative of lower Eocene Zones NP9 and NP10 and Subzone P6a. The presence of rare, poorly preserved benthic foraminifers typical of the late Paleocene in Core 199-1217A-17X suggests that the site may have drilled through the P/E boundary. However, the presence of lower Eocene nannofossils in these same samples raises the possibility that the benthic foraminifers have been reworked from older strata.
Red-clay and chert facies barren of nannofossils characterize all core catcher samples except for Sample 199-1217A-17X-CC, containing a P/E boundary assemblage from Zone NP9. This core catcher sample also contains basalt. The first downhole occurrence of nannofossils was observed in a short interval in Sections 199-1217A-4H-2 through 4H-4, indicating a brief interval of carbonate preservation interrupting the red-clay facies. Five samples were investigated from this carbonate-bearing sediment and all showed severe calcite dissolution.
The best-preserved sample was observed in Section 199-1217A-4H-4, 10 cm, and includes the following species: abundant Dictyococcites bisectus, Dictyococcites hesslandii, Reticulofenestra dictyoda, common Discoaster deflandrei, Discoaster tanii, Sphenolithus moriformis, and rare Reticulofenestra umbilicus 
14 µm, Coccolithus pelagicus, Sphenolithus predistentus, and Sphenolithus tribulosus. Many isolated nonbirefringent placolith shields were observed, which are probably distal shields of C. pelagicus. A 2-cm-thick whitish layer in red clays from Section 199-1217A-4H-6 contained a similar nannofossil assemblage, although only rare D. tanii was observed in this layer.
The presence of rare R. umbilicus and S. tribulosus, with abundant D. bisectus and the absence of both Eocene rosette-shaped discoasters and Ericsonia formosa, suggests that Sections 199-1217A-4H-4 through 4H-6 belong to Zone NP22 of the lower Oligocene (Chron C12r).
Section 199-1217A-16X-1 and upper Section 16X-2 contains a mottled carbonate chalk unit belonging to Zones NP10 and NP9. A dissolved but otherwise indigenous lower Eocene assemblage characterizes Sample 199-1217A-16X-1, 6 cm, with common Tribrachiatus contortus, indicating Zone NP10. Calcite overgrowth complicates accurate identification of the evolutionary transitions in the Rhombaster-Tribrachiatus lineage. Yet Tribrachiatus bramlettei was observed from Sample 199-1217A-16X-1, 24 cm, to Sample 16X-1, 78 cm (NP10). The next deeper sample (16X-1, 103 cm) contains abundant Rhomboaster cuspis, and T. bramlettei is absent indicating upper Zone NP9.
Small chalk pockets embedded in a piece of chert (Sample 199-1217A-16X-2, 73 cm) contain common Discoaster multiradiatus and R. cuspis among a dissolved, indigenous lower Eocene assemblage lacking Fasciculithus spp., which indicates upper Zone NP9.
Core 199-1217A-17X only had recovery in the core catcher (pieces of basalt and some clay), which yielded a corroded assemblage with common to abundant D. multiradiatus and Fasciculithus tympaniformis indicating lower Zone NP9 of the uppermost Paleocene. Other species observed belong to the genera Chiasmolithus, Coccolithus, Cruciplacolithus, Prinsius, Sphenolithus, and Toweius.
Sediments from Site 1217 are barren of planktonic foraminifers except for the burrow-mottled chalk recovered in Core 199-1217A-16X. Preservation of foraminifers is highly variable through this section. Samples 199-1217A-16X-1, 27-29 cm, and 16X-1, 74-75 cm, contain heavily dissolved assemblages in which only the more resistant species remain. A few degraded specimens of Morozovella subbotinae, Morozovella gracilis, Morozovella aquea, Acarinina soldadoensis, and Acarinina coalingensis in these samples indicate an early Eocene (Subzones P6a and P6b) age. Preservation is very poor in Sample 199-1217A-16X-1, 105-107 cm, and no age diagnostic species are identifiable. Preservation improves slightly downcore, and Sample 199-1217A-16X-2, 19-21 cm, contains a reasonably diverse assemblage of early Eocene planktonic foraminifers of a typically tropical nature. Specimens are common and poorly to moderately well preserved. Based on the occurrence of Morozovella marginodentata, M. gracilis, M. subbotinae, and M. aquea and in the absence of Subzone P6b marker M. formosa and the Paleocene Zone P5 marker Morozovella velascoensis, we place this sample in lower Eocene Subzone P6a. The sample also contains A. soldadoensis, Acarinina wilcoxensis, Globanomalina pseudoimitata, Subbotina patagonica, Parasubbotina varianta, and the small unidentified species reported at Site 1215 (cf. Tenuitella? sp).
Benthic foraminifers are largely absent from the red clay and radiolarian ooze and are present only occasionally at certain intervals in the recovered sections from Site 1217. When present, benthic foraminifers are composed of either agglutinated or calcareous assemblages. The agglutinated assemblages show low diversity, are poorly preserved, and of little stratigraphic use. In contrast, calcareous foraminiferal assemblages are well preserved and relatively diverse, but such assemblages are limited in stratigraphic occurrence. Samples 199-1217A-1H-CC through 3H-CC; 7H-CC through 11H-CC; 12H-1, 0-5 cm; 15X-1, 29-30 cm, and core catchers between Samples 199-1217B-5H-CC and 8H-CC are barren of benthic foraminifers. The distribution of benthic foraminifers is reported in Table T2.
Well preserved assemblages of benthic foraminifers are found in Samples 199-1217A-4H-2, 114-116 cm; 4H-3, 27-29 cm; 4H-4, 10-12 cm; and 4H-6, 51-53 cm. Of these, the assemblage in Sample 199-1217A-4H-2, 114-116 cm, shows the greatest diversity. The most common species are Globocassidulina sp., Nuttallides umbonifer, Gyroidinoides spp., and large specimens of Cibicidoides grimsdalei and Cibicidoides havanensis, which indicate lower bathyal to abyssal depths (van Morkhoven et al., 1986). The latter two species range from the lower Eocene to the Miocene but are typically most abundant in Eocene-Oligocene deep-sea sediments (van Morkhoven et al., 1986). N. umbonifer is a common species in the deep sea after the extinction of Nuttallides truempyi and has its last occurrence in the uppermost Eocene (Zone P17; Berggren and Miller, 1989). However, N. truempyi more commonly disappears near the middle/upper Eocene boundary (planktonic foraminiferal Zone P15) at abyssal depths (Berggren and Miller, 1989). Assemblages that contain N. umbonifer in the absence of N. truempyi have also been recognized in bathyal late Eocene sediments (Nomura, 1995). Based on this information, the assemblage of Sample 199-1217A-4H-2, 114-116 cm, can be assigned to a late Eocene or younger age.
Samples 199-1217A-16X-2, 19-20 cm, and 17X-CC contain calcareous foraminifers such as N. truempyi, Anomalinoides spissiformis, Bulimina semicostata, Globocassidulina globosa, and Abyssamina poagi. Planktonic foraminifers are also present and nearly in equal abundance to the benthic assemblage with a planktonic:benthic ratio of 1.2:1. Gavelinella beccariiformis, Aragonina velascoensis, Pullenia coryelli, and Gyroidinoides globosus, all of which belong to the Velasco-type foraminifers (van Morkhoven et al., 1986), are rare in Sample 199-1217A-17X-CC. However, they are badly preserved and may be reworked from older sediment. Foraminifer assemblages in these two samples are dominated by N. truempyi and A. poagi, and they account for 50% of the total assemblage of Sample 199-1217A-16X-2, 19-20 cm, and 69% of Sample 199-1217A-17X-CC. The high abundance of these two species suggests that these assemblages belong to the early Eocene.
The upper red clay (Unit I) of Hole 1217A contains rare to few, poorly preserved radiolarians from Sample 199-1217A-1H-CC to 6H-6, 45-47 cm. Samples 199-1217A-4H-5, 45-47 cm, and 4H-6, 45-47 cm, probably belong to Zone RP19, although the presence of reworked specimens of Thyrsocyrtis triacantha and Eucrytidium fistuligerum cast some doubt on the zonal designation. The first occurrence of Cryptocarpium azyx in Sample 199-1217A-6H-CC places this sample in Zone RP17, but the faunal assemblage between that sample and the Zone RP19 samples is too poor to allow placement of the RP17/RP18 boundary. These samples were particularly difficult to disaggregate, and the clay content could not be completely eliminated. All subsequent downhole samples contain a rich, well preserved middle Eocene radiolarian fauna. Samples 199-1217A-7H-2, 45-47 cm, through 1217A-7H-CC belong to Zone RP16. At Section 199-1217A-7H-6, ~134-138 cm, there is a band of pure radiolarian ooze. Samples 199-1217A-8H-CC through 9H-CC fall within Zone RP15. The boundary between Zones RP15 and RP14 is defined as the evolution from Podocyrtis mitra to Podocyrtis chalara but is placed here at the first occurrence of P. chalara. Using this definition, the remainder of the studied interval down to Sample 199-1217A-12H-1, 1-5 cm, belongs to Zone RP14.
Sampling from Holes 1217B and 1217C was designed to capture the intervals missed during coring of Hole 1217A. In Hole 1217B, Samples 199-1217B-2H-4, 110-112 cm, and 3H-6, 134-136 cm, contained an impoverished fauna lacking age-diagnostic taxa. The rest of the samples studied contain a common to abundant and well-preserved assemblage. Samples 199-1217B-3H-2, 32-34 cm; 3H-3, 84-86 cm; and 4H-1, 50-52 cm, belong to Zone RP18. Samples 199-1217B-4H-1, 140-142 cm, and 4H-2, 50-52 cm, are assigned to Zone RP17; Samples 199-1217B-5H-1, 80-82 cm, and 5H-2, 80-82 cm, to Zone RP16; and the remaining samples down to 199-1217B-7H-2, 130-132 cm, fall within Zone RP14.
Four samples were taken from Hole 1217C. The uppermost material from Sample 199-1217C-3H-1, 60-62 cm, contains a moderately well preserved, but somewhat sparse, fauna belonging to Zone RP18. The next sample (199-1217C-3H-2, 10-12 cm) belongs to the same zone but contains a much richer assemblage. Sample 199-1217C-3H-2, 98-100 cm, falls within Zone RP17, and Sample 5H-1, 120-122 cm, falls within Zone RP15.
