Sediments recovered from the three holes cored at Site 897 provide a discontinuous record for the Pleistocene through the Early Cretaceous (Fig. 21). Present is a thick (310 m) Pliocene-Pleistocene sequence, a much thinner (68 m) Miocene deposit containing two unconformities, a thick (155 m) Oligocene deposit, and middle and upper Eocene sediments (87 m), below which a brown claystone deposit of unknown age overlies an Early Cretaceous deposit. Calcareous nannofossils generally are present throughout the sequence, except for the brown claystone deposit, and provide a well-constrained stratigraphy for the recovered sequence. Planktonic and benthic foraminifers are abundant to common in the Pleistocene and upper Pliocene deposits, but rare to absent throughout most of the remaining cored interval.
Site 897 is situated in the eastern part of the Iberia Abyssal Plain in a water depth of 5320 m. The calcareous nannofossils define a stratigraphic succession from the upper Pleistocene (Zone NN21 of Martini, 1971) to the Lower Cretaceous (Zone CC4 of Sissingh, 1977). Most of the material has been deposited by turbidity currents and part of the section is incomplete (zones NN14 through NN11 are missing) or has been condensed into a short interval (NN10 through NN5). Carbonate-free red-brown claystone, barren of calcareous nannofossils, represents a long interval between the middle Eocene (NP14) and the upper Aptian. About 15 m of pre-Albian (upper lower Hauterivian to the lower upper Aptian) sediment represents the earliest sediment deposited since the rupture of the continental crust. Within this interval, the percentage of shallower water forms of the genera Lithraphidites, Micrantholithus, and Nannoconus decreases progressively from the Hauterivian to the Aptian, indicating a deepening of this site toward a more deep-sea environment. The top of this interval is composed primarily of small debris-flows interbedded with less calcareous claystones that contain a poorly preserved, monospecific assemblage of Watznaueria spp. This indicates that subsidence of the margin has occurred to depths near or below the carbonate compensation depth (CCD), which has been estimated as being at 3000 m in the North Atlantic by late Aptian (Tucholke and Vogt, 1979).
The upper 55.2 m of the sedimentary section from Site 897 was recovered from Hole 897A. The biostratigraphic resolution is limited because of poor core recovery. Calcareous nannofossils are few to very abundant and moderately to well preserved. Few to common specimens of Emiliania huxleyi and Emiliania pujosae in Samples 149-897A-1R, 55 cm, and 149-897A-1R, 105 cm, indicate Zone NN21 from the upper Pleistocene. In both samples, no shift in dominance between small Gephyrocapsa spp. and Emiliania huxleyi was observed, and small Gephyrocapsa spp. (>2.5 m) having an open central area dominate the assemblage (morphogroup 1; Gard and Backmann. 1990). This led to an assigned age of 0.186 Ma for the assemblage. In Sample 149-897A-1R-CC, the presence of only Emiliania pujosae indicates an age between 0.26 and 0.36 Ma. Sample 149-897A-2R-CC contains rare Reticulofenestra sp. A (>5.0-6.0 m), rare Reticulofenestra asanoi, and common Gephyrocapsa oceanica (>4.0-5.0 m). Sample 149-897A-3R-1, 30 cm, has few Gephyrocapsa oceanica (>5.0-5.5 m), very rare Helicosphaera inversa, rare Reticulofenestra sp. A(>5.0-6.0 m), very rare Reticulofenestra sp. A (>6.5 m), and rare circular Pseudoemiliania lacunosa, which indicate an age from 0.8 to 0.9 Ma. Sample 149-897A-3R-CC contains Gephyrocapsa oceanica (>4.0-5.0 m), Gephyrocapsa caribbeanica, and rare elliptical Pseudoemiliania lacunosa. The interval from Samples 149-897A-4R-1, 58 cm, to -5R-3, 32 cm, contains abundant Gephyrocapsa oceanica (>4.0-5.0 m), Gephyrocapsa oceanica (>5.5 m), and Gephyrocapsa caribbeanica. This indicates an age between 1.10 and 1.37 Ma. Samples 149-897A-5R-CC and -6R-CC contain Gephyrocapsa oceanica (>4.0-5.0 m), which indicates an early Pleistocene age in the middle of Zone NN19 between 1.37 and 1.64 Ma. Most of the core-catcher samples (149-897A-2R-CC to -6R-CC) contain few to very abundant Coccolithus doronocoides, scattered occurrences of Discoastervariabilis, Discoaster sp. (5 rays), and Discoaster pentaradiatus, indicating that a large part of the material has been recycled from the Pliocene. Also reworked from the Pliocene are rare Clacidiscus macintyrei, making the use of this marker difficult. An assignment of the Pleistocene age results from the size of Gephyrocapsa oceanica (>4.0 m). The assemblage of Sample 149-897A-6R-CC has moderately preserved, abundant calcareous nannofossils and contains common Coccolithus pelagicus, indicating the presence of cooler water.
The Cenozoic sediments recovered in Hole 897C from Samples 149-897C-1R-CC to 149-897C-59R-4, 10 cm, cover a long period of time, from the early Pleistocene to the middle Eocene. Below this Cenozoic interval, red-brown claystones barren of calcareous nannofossils were recovered (lithostratigraphic Subunit IIIA and most of Subunit IIIB; see "Lithostratigraphy" section, this chapter). Calcareous nannofossils were found in the majority of the core-catcher samples. The estimated abundances of nannofossil specimens in the core-catcher samples range from barren (Samples 149-897C-7R-CC, -29R-CC, -34R-CC, -40R-CC, -44R-CC, -46R-CC, and -47R-CC) to very abundant. Most core-catcher samples contain rare to few reworked specimens from the Cretaceous. Reworked Cenozoic specimens from the Paleocene to the Pliocene, having a high percentage of Miocene forms, were also observed in Pliocene sediments.
Pleistocene. The Pleistocene sediments extend from Section 149-897C-1R-1 to Sample 149-897C-11R-CC. The nannofossil assemblages mostly are well preserved, and the abundance of nannofossil specimens ranges from barren (Sample 149-897C-7R-CC) to very abundant.
Samples 149-897C-1R-CC to -11R-CC contain rare to few Gephyrocapsa oceanica (>4.0-4.2 m), few Hellicosphaera sellii, few Calcidiscus macyntyrei, rare to common Reticulofenestra asanoi, abundant Coccolithus doronocoides, and few to common Coccolithus pelagicus (and Coccolithus crassipons).
Pliocene. The Pliocene/Pleistocene boundary was placed between Samples 149-897C-11R-CC and 149-897C-12R-CC by the lowest occurrence (LO) of very rare Gephyrocapsa oceanica (4.0 m) in Sample 149-897C-11R-CC. The Pliocene interval extends from Samples 149-897C-12R-CC to -26R-1, 76 cm. The calcareous nannofossils range from few to abundant and are moderately to well preserved. Sample 149-897C-12R-CC was placed in Zone NN19A on the absence of Discoaster brouweri and Gephyrocapsa caribbeanica. Zones NN18-NN16 are missing. The interval 149-897C-14R-CC to -25R-CC has been assigned to Zone NN15. The highest occurrence (HO) of Reticulofenestra pseudoumbilica in Sample 149-897C-14R-CC indicated Zone NP15.
In Sample 149-897C-15R-CC, the co-occurrence of rare Reticulofenestra pseudoumbilica and Sphenolithus neoabies, abundant Pseudoemiliania lacunosa and Reticulofenestra ampla and of very abundant Coccolithus doronocoides suggests the top of Zone NN15. Sample 149-897C-17R-CC contains rare Sphenolithus abies. Sample 149-897C-25R-CC contains few Reticulofenestra pseudoumbilica, whereas Sample 149-897C-26R-CC yields few Pseudoemiliania lacunosa, few Discoaster tamalis, and abundant Coccolithus doronocoides. Sample 149-897C-27R-CC contains few Sphenolithus abies, common Sphenolithus neoabies and Reticulofenestra pseudoumbilica, rare Discoaster asymmetricus and Discoaster brouweri, few Thoracosphaera albatrosiana, and no Pseudoemiliana lacunosa, Discoaster tamalis, Discoaster quinqueramus, Amaurolithus spp., or Ceratolithus spp.
Miocene. The Miocene/Pliocene boundary was placed between Samples 149-897C-26R-1, 76 cm and -26R-CC. The Miocene interval extends down to Samples 149-897C-33R-CC and -34R-CC. The interval from Sample 149-897C-26R-CC to -28R-CC was placed in the upper Miocene Zone NN10, and corresponds to the lithostratigraphic Subunit IIA and to the upper part of Subunit IIB. Sample 149-897C-28R-CC contains very abundant and well-preserved assemblages and corresponds to the upper part of lithostratigraphic Subunit IIA (see "Lithostratigraphy" section, this chapter). This sample represents the Miocene Zone NN10, based on the presence of Discoaster bollii, Discoaster loeblichii, and Sphenolithus abies and the absence of Discoaster quinqueramus and Discoaster hamatus. A hiatus representing part of the lowermost Pliocene and the upper Miocene (Zones NN12 to NN11) lies between Samples 149-897C-26R-1, 76 cm, and -26R-CC. Sample 149-897C-29R-CC is barren of nannofossils. The interval 149-897C-30R-CC to -33R-CC represents the lower Miocene (Zones NN4-NN1). A second major hiatus, or a very condensed section, lies between this interval and Sample 149-897C-28R-CC and may represent the time from Zones NN10 to NN4. Sample 149-897C-30R-CC corresponds to Zone NN4, based on the presence of Helicosphaera ampliaperta and Sphenolithus heteromorphus. Sample 149-897C-31R-CC was placed in Zone NN2, as suggested by very rare Cyclicargolithus abisectus (>10 m) and the presence of Discoaster druggii. Sample 149-897C-33R-CC corresponds to the lowermost Miocene (Zone NN1), as indicated by common Cyclicargolithus abisectus, few Reticulofenestra bisecta, rare Sphenolithus ciperoensis, and very rare Zygrhablithus bijugatus. The HO of Helicosphaera recta occurs below this sample.
Oligocene. The Oligocene occurs from Samples 149-897C-34R-CC and -35R-CC to -49R-CC. Sample 149-897C-35R-CC was assigned to Zone NP25 on the presence of Helicosphaera recta, Triquetrorhabdulus carinatus, and few Sphenolithus ciperoensis. Samples 149-897C-36R-CC to -38R-CC are from the same zone. Sample 149-897C-39R-CC has been assigned to Zone NP24 on the presence of Sphenolithus dissent's, Sphenolithus ciperoensis, and Helicosphaera compacta.
Samples 149-897C-40R-CC and -41R-CC are barren of nannofossils. Sample 149-897C-42R-CC has abundant and well-preserved calcareous nannofossils. The presence of Sphenolithus distentus and the absence of Sphenolithus predistentus indicate the upper Oligocene Zone NP24. Sample 149-897C-45R-CC lies within the base of Zone NP23, as determined by the presence of Sphenolithuspredistentus and a transitional form of Sphenolithus predistentus. Samples 149-897C-46R-CC and -47R-CC are barren of nannofossils. Sample 149-897C-48R-CC has rare and poorly preserved nannofossils. Zone NP21 (lowermost Oligocene) occurs in Sample 149-897C-49R-CC, as indicated by the presence of Reticulofenestra umbilica, Coccolithusformosus, Isthmolithus recurvus, common Clausicoccus fenestratus, Clausicoccus obrutus, and Clausicoccus subdistichus, and by the absence of Discoaster barbadiensis.
Eocene. The Eocene is represented by the interval 149-897C-50R-CC to -59R-4, 10 cm. The interval 149-897C-50R-CC to -52R-CC was placed in Zone NP19/NP20 on the presence of Discoaster barbadiensis, Discoaster saipanensis, Ericsoniaformosa, and Isthmolithus recurvus. Sample 149-897C-53R-CC contains abundant, well-preserved nannofossils from Zone NP18, as indicated by the presence of Chiasmolithus oamaruensis and the absence of Isthmolithus recurvus and Chiasmolithus solitus. Sample 149-897C-54R-CC has few, poorly preserved nannofossils. Sample 149-897C-55R-CC was assigned to Zone NP17 on the basis of the presence of Chiasmolithus grandis, Discoaster tanii, in the absence of Chiasmolithus oamaruensis, and Chiasmolithus solitus. Samples 149-897C-56R-CC and -57R-CC have been placed in Zone NP16, as suggested by the presence of Campylosphaera dela, Discoaster tanii nodifer, and Sphenolithus furcatolithoides. Samples 149-897C-58R-CC to -59R-4, 9 cm, are in Zone NP15, as indicated by the presence of sporadic Blackites gladius, Discoaster bifax, sporadic Chiasmolithus gigas, Nannotetrina alata, and Sphenolithus furcatolithoides. Within Zone NP15, the interval 149-897C-59R-3, 97 cm, to -59R-3, 150 cm, is barren.
The Cenozoic interval recovered in Hole 897D extends from the middle Eocene (NN15) to the lower middle Eocene (NN14). Samples 149-897D-1R-CC and -2R-CC represent the middle Eocene Zone NN15. The calcareous nannofossils have been excellently preserved and are highly diverse. The presence of Chiasmolithus gigas in Sample 149-897D-1R-CC indicates the middle of Zone NP15. In Sample 149-897D-2R-CC, the presence of Nannotetrina alata, Discoaster kuepperi, and Discoaster lodoensis in the assemblage characterizes the boundary of Zones NP14/NP15. Sample 149-897D-3R-5, 1 cm, which is 37 cm above the transition between the lower part of lithostratigraphic Subunits IIC and IIIA (brown-red claystone), contains Discoaster kuepperi, Discoaster multiradiatus, and Discoaster sublodoensis, which indicate Zone NP14.
Sediments below Sample 149-897D-3R-CC, situated near the top of lithostratigraphic Subunit IIIA, are barren of nannofossils.
From Holes 897C and 897D, we recovered a thin Mesozoic section of debris flows having calcareous silty claystone (lithostratigraphic Subunit IIIB) and calcareous claystone (lithostratigraphic Subunit IV). Most of these intervals contain moderately to well-preserved nannofossils having moderate-to-abundant species diversity. However, in the upper part of lithostratigraphic Unit IV, a few intervals in Section 149-897C-62R-4 have poorly preserved nannofossils, with a low diversity assemblage composed mostly of the dissolution-resistant form Watznaueria barnesae (Sample 149-897C-62R-4, 63 cm). Samples barren of nannofossils include 149-897C-62R-4, 74 cm, and -65R-2, 5-10 cm.
We have applied the zonation of Sissingh (1977: "CC" zones) to the Lower Cretaceous using primary zonal markers and additional events (see "Explanatory Notes," Fig. 8, this volume). In the uppermost part of the Cretaceous succession in Hole 897C (base of Subunit IIIB), the interval 149-897C-62R-4, 38-39 cm, to -64R-CC, 1 cm, was placed in the Aptian. Sample 149-897C-62R-CC, at the top of lithostratigraphic Unit IV, has an assemblage that contains Praedicosphaera spinosus, Lithastrinus floralis, Micrantholithus obtusus, Micrantholithus hochulzii, Micula infracretacea, Nannoconus globulus, Nannoconus buckeri, Nannoconus steinmanii steinmanii, and Rucinolithus terebrodentarius, which indicate an early late Aptian (CC7) age. Sample 149-897C-65R-2, 114 cm, contains a very rich, well-preserved assemblage from the upper Barremian (CC6) with Rucinolithus terebrodentarius, Calcicalathina aff. C. oblongata, Chiastozygus aff. C. litterarius, Reinhardtites praesisyphus, Conusphaera rothii, Zeugrhabdotus diplogrammus, Hayesites radiatus, Markalius circumradiates, Markalius ellipticcus, Polypodorhabdus madingleyensis, Micrantholithus obtusus, Zeugrhabdotus elegans, Parhabdolithus infinitus, Microstaurus quadratus, Microstaurus chiastus, Rhagodiscus asper, Nannoconus steinmanii steinmanii, and Reinhardtites fenestratus. The oldest sediments recovered at Site 897 were observed in Sample 149-897C-65R, 127 cm. A Hauterivian (CC4) age is indicated by Cruciellipsis cuvillieri, Reinhardtites praesisyphus, Markalius circumradiatus, Micrantholithus hoschulzii, Nannoconus globulus, and Calcicalathina aff. C. oblongata. This assemblage also contains unusually abundant Zeugrhabdotus embergeri. Sample 149-897C-70R-3, 26 cm, was placed in the Barremian-late Hauterivian by the presence of Calcicalathina obongata, Calcicalathina aff. C. oblongata, Ellipsagelosphaera britannica, Markalius circumradiatus, Nannoconus steinmanii, Reinhardtites praesisyphus, Retecapsa angustiforata, and Rhagodiscus asper.
Sample 149-897D-6R-CC in the upper part of lithostratigraphic Unit IV has common, fairly well-preserved nannofossils from the middle lower Aptian (CC7), including Conusphaera mexicana, Hayesites irregularis, Mirantholithus obtusus, and Micrantholithus hoschulzii. Sample 149-897D-7R-1, 38 cm, is lower Aptian (CC7) and consists of an abundant, well-preserved assemblage with Conusphaera mexicana, Micula infracretacea, and Vagalapilla matalosa (murolith). Sample 149-897D-7R-CC contains Calcicalathina oblongata, Diazomalithus lehmanii, Micrantholithus obtusus, and Micrantholithus hoschulzii, suggesting an age not younger than late early Barre-mian. Sample 149-897D-8R-CC has a few, poorly preserved nannofossils and no zonal markers. Samples 149-897D-9R-CC and -10R-CC contained serpentinized peridotite. Sample 149-897D-10R-4, 91 cm, has an abundant, well-preserved assemblage from the lower Barremian with Calcicalathina aff. C. oblongata, Conusphaera mexicana, Conusphaera rothii, Manivitella pemmatoidea, Markalius circumradiatus, Micrantholithus obtusus, Micrantholithus hoschulzii, Nannoconus steimanii steinmanii, Nannoconus ligius, Nannoconus buckeri, Nannoconus globulus, Reinhardtites praesisyphus, Rucinolithus terebrodentarius, Tegumentum stradneri, and Zygolithus sp. A.
Planktonic foraminifers in core-catcher samples from Holes 897A, 897C, and 897D were examined to establish preliminary ages for the sediments. The number of planktonic foraminifers generally was low; most of the samples yielded a low-diversity planktonic foraminiferal assemblage having moderate to poor preservation. More planktonic foraminifers having better preservation were present in Hole 897 A and the upper sections of Hole 897C. Similar patterns were observed in the benthic foraminifer assemblages.
Planktonic foraminifers identified in Hole 897A are listed in Table 6. Foraminifers of late Pleistocene age were identified in Samples 149-897A-1R-CC and -2R-CC. The presence of Globorotalia truncatulinoides in Sample 149-897A-1R-CC allowed us to assign it to Zone N23. The co-occurrence of Globorotalia tosaensis and G. truncatulinoides in Sample 149-897A-2R-CC enabled us to place it in the upper part of Zone N22 or the lower part of Zone N23. The interval 149-897A-3R-CC to -5R-CC contains G. truncatulinoides and G. tosaensis together with Globigerinoides extremus and can be assigned to the basal part of Zone N22, which is of latest Pliocene to early Pleistocene age. No age-indicative species were identified in Sample 149-897A-6R-CC. Abyssal and reworked shallow-water benthic foraminifers were identified in all core-catcher samples.
A late Pliocene to early Pleistocene age sequence (lower Zone N22) was identified in the interval 149-897C-1R-CC to -11R-CC (Table 7). These samples contain Globorotalia truncatulinoides, Globorotalia tosaensis, and Globigerinoides extremus. This interval yielded common to abundant planktonic foraminifers that were moderately to well preserved. Low to moderate numbers of well-preserved abyssal and reworked shallow-water benthic foraminifers also were identified in this interval. Sample 149-897C-5R-CC is barren of planktonic and benthic foraminifers.
Pliocene age sediments (Zones N19 to N21) were identified in the interval 149-897C-12R-CC to -17R-CC. These samples are characterized by the absence of G. truncatulinoides and Sphaeroidinellopsis seminulina, and, with no zonal markers present, no further age refinement was possible.
Early to early late Pliocene age sediments were identified in the interval 149-897C-18R-CC to -25R-CC. This interval is marked by the presence of 5. seminulina at the top and Globorotalia crassaformis at the base and can be assigned to Zone N19.
Sample 149-897C-26R-CC contains Globorotalia ronda and S. seminulina. The sample was assigned to Zones N18 and N19, which are of latest Miocene to early late Pliocene age. No zonal marker species were present in Sample 149-897C-27R-CC. Sample 149-897C-28R-CC is characterized by the presence of Neogloboquadrina acostaensis and the absence of Neogloboquadrina humerosa. The sample can be assigned to Zone N16, which is of late Miocene (Tortonian) age. A hiatus was inferred between Samples 149-897C-26R-CC and -28R-CC, where Zone N17 is missing. No zonal marker species were present in Sample 149-897C-29R-CC. Sample 149-897C-30R-CC contains Catapsydrax stainforthi and Globorotalia fohsi peripheroronda and can be assigned to Zones N6 (upper) and N7, which are of early Miocene age. A hiatus was interpreted between Samples 149-897C-28R-CC and -30R-CC, where Zones N8 to N15, from late early to middle Miocene, are missing. Samples 149-897C-31R-CC, -33R-CC, and -34R-CC are barren.
Sample 149-897C-35R-CC contains Globigerinoides primordius and can be assigned to Zones P22 (upper part) to "N4," which are of late Oligocene to earliest Miocene age. Samples 149-897C-36R-CC and -37R-CC are barren. Sample 149-897C-38R-CC contains no zonal marker species.
The interval 149-897C-39R-CC to -41R-CC is characterized by the absence of Globigerinoides spp. and the absence of Globigerina ciperoensis angulisuturalis. It was assigned to the upper part of the late Oligocene (Zone P22).
Sample 149-897C-42R-CC contains Globigerina ciperoensis angulisuturalis and can be assigned to the lower part of Zone P22, which is also of late Oligocene age. The interval 149-897C-43R-CC to -45R-CC is characterized by the presence of Globorotalia opima opima at the top and Globigerina ciperoensis angulisuturalis at the base. The interval can be assigned to Zone P21, which is of late early to early late Oligocene age.
Sample 149-897C-46R-CC contains no marker species, and Samples 149-897C-47R-CC and -48R-CC are barren of planktonic and benthic foraminifers. Sample 149-897C-49R-CC is marked by the presence of Pseudohastigerina micra and can be assigned to Zones P18 and lower part of P19/20, which are of early Oligocene age. Sample 149-897C-50R-CC is barren of planktonic foraminifers. Samples 149-897C-51R-CC and -52R-CC contain no marker species. Analysis of additional Sample 149-897C-51R-1, 13-15 cm, yielded Hantkenina spp., indicating that late Eocene age strata had been reached (Zones P15-P17).
Sample 149-897C-53R-CC contains Globigerina eocaena and was interpreted as late Eocene age, because sediments of this age already were recorded in Sample 149-987C-51R-1, 13-15 cm. Sample 149-897C-54R-CC is barren of planktonic foraminifers. The interval 149-897C-55R-CC to -58R-CC contains a middle Eocene planktonic foraminiferal assemblage (Zones P11(upper)-P14) characterized by the presence of Truncorotaloides topilensis and Truncorotaloides rorhi at the top and Globigerinatheka index at the base. Sample 149-897C-59R-CC is characterized by rare specimens of Morozovella spinulosa and the absence of Globigerinatheka index. The sample can be assigned to Zones P9 to P11 (lower), which are of late early to early middle Eocene.
Samples 149-897C-60R-CC and -61R-CC are barren of planktonic foraminifers and contain rare agglutinated benthic foraminifers that are not age-diagnostic and rare ichthyoliths. Samples 149-897C-60R-1, 83-85 cm; -61R-2, 12-14 cm; -61R-2, 17-19 cm; -61R-2, 92-94 cm; and -61R-4, 24-26 cm; also contain agglutinated benthic foraminifers (Glomospira spp. and Recurvoides spp.), radiolarians, and ichthyoliths. Sample 149-897C-62R-CC is barren of planktonic and benthic agglutinated foraminifers. Samples 149-897C-62R-1, 32-34 cm;-62R-1, 69-71 cm;-62R-3, 54-56 cm; and -62R-4, 11-13 cm; contain no foraminifers, radiolarians, diatoms, or ichthyoliths. Sample 149-897C-62R-2, 48-50 cm, contains a single specimen of Glomospira spp., while radiolarians, diatoms, and ichthyoliths are absent. Sample 149-897C-62R-4, 54-56 cm, contains very small hed-bergellids (Hedbergella delrioensis) and globigerinoidinids, indicat-ing an Aptian to Albian age. A single specimen of a cone-shaped radiolarian was found in this sample. Samples 149-897C-63R-CC and -65R-CC are barren of planktonic and benthic foraminifers, radio-larians, diatoms, and ichthyoliths.
The interval 149-897D-1R-CC to -2R-CC contains a middle Eocene (Zones P11-lower P12) planktonic foraminiferal assemblage characterized by the co-occurrence of Acarinina pentacamerata and Globigerinatheka index. The interval 149-897D-3R-CC to -5R-CC is barren of planktonic foraminifers. Sample 149-897D-3R-CC contains rare ichthyoliths. Samples 149-897D-4R-CC and -5R-CC contain rare agglutinated benthic foraminifers (Glomospira spp. and Recurvoides spp.) and rare ichthyoliths. Sample 149-897D-6R-CC is characterized by the presence of a diverse assemblage of very small hedbergellids and globigerinelloids, indicating an Aptian to Albian age. The species Hedbergella simplex, found in this core, would restrict the age of this core to the Albian, as the first evolutionary appearance of this species is in lower Albian sediments (Tourmakine and Luterbacher, 1985). Also characteristic of this sample are the relatively few cone-shaped radiolarians. Sample 149-897D-7R-CC contains pyritized radiolarians and diatoms. Sample 149-897D-8R-CC is completely barren of any microfauna.