(320.2–320.4 mcd), and Zone P0 was not recognized.
At Site 1267, Pleistocene through upper Maastrichtian sediments were recovered. Nannofossils are present in almost all samples, showing generally moderate preservation with reworking and dissolution in the upper Eocene through Miocene and dissolution in the Maastrichtian (Fig. F19). Planktonic foraminifers are present in moderate to high abundances and with variable preservation because of dissolution in the Pliocene sediments through upper middle Eocene and Maastrichtian. Reworked specimens are common in the Pleistocene and Miocene through the middle Eocene (Fig. F19). Benthic foraminifers are rare and have good preservation in some parts of the section, but in the lower Pliocene through the upper lower Eocene and the middle upper Paleocene, benthic foraminifers, large echinoid spines, and ostracodes are reworked and transported downslope from water depths of no less than ~600–1500 m.
Shipboard examination of calcareous nannofossils and planktonic foraminifers permits preliminary zonal and stage assignments (Fig. F19; Tables T5, T6, T7, T8). Biochronological ages plotted against mcd delineate overall sedimentation rates (Fig. F20) (see "Age Model and Mass Accumulation Rates").
The Pleistocene–uppermost Miocene and lower Eocene–upper Maastrichtian (including the P/E and K/P boundaries) are biostratigraphically complete at shipboard resolution, but the middle Miocene–upper middle Eocene sediments are difficult to zone because of massive reworking and severe dissolution, and they are condensed or interrupted by unconformities. An "unconformity" corresponding to the earliest late Miocene through early Miocene (~10.5–22.8 Ma) occurs between 108 and 113 mcd in Core 208-1267A-11H. Sediments between 113 and 115 mcd are early Miocene, and sediments between 115 and 129 mcd cannot be dated precisely and might be Oligocene in age. Sediments between 130 and 146 mcd are earliest Oligocene (~31.7–32.9 Ma), and the highly condensed sequence between 115 and 130 mcd thus represents ~8–9 m.y. Sediments between 146 and 151 mcd are problematic because of severe dissolution and massive reworking, and they could be either earliest Oligocene or late Eocene in age. Thus, the E/O boundary cannot be identified unequivocally. At 151 mcd, sediments are ~42.3 Ma (middle Eocene). The interval between 146 and 151 mcd thus represents a large part of the late and late middle Eocene.
Benthic foraminifers indicate generally lower abyssal depths (>3000 m) from the late Paleocene through the Pleistocene, although the paleodepths of some samples could not be ascertained because of intensive downslope transport, reworking, and dissolution. The paleodepth was transitional between upper and lower abyssal (~3000 m) in the middle part of the Paleocene and upper abyssal (<3000 m) during the Maastrichtian through early Paleocene.
Calcareous nannofossil assemblages contained in core catcher samples for all holes and additional samples taken at critical intervals in Hole 1267A were examined. Depth and age estimates of key biostratigraphic markers are shown in Table T5; Table T6 shows a distribution chart of the core catcher samples. Nannofossils have good to moderate preservation throughout the section and are always present except for some intervals in Core 208-1267A-12H and a few centimeter-thick intervals in Core 22H just above the P/E boundary. Paleogene assemblages show dissolution of placoliths and overgrowth of discoasterids with secondary calcite.
The recovered section represents an almost complete record of the upper Pleistocene (Zone CN15/NN21) through the Pliocene/Pleistocene boundary in Cores 208-1267A-1H through 2H. The complete succession of Pleistocene nannofossil assemblages is present, including the events based on the size change of Gephyrocapsa. The Pliocene/Pleistocene boundary is between the lowest occurrence of medium Gephyrocapsa spp. and the highest occurrence of Discoaster brouweri in Sample 208-1267A-2H-5, 65 cm, and Section 2H-CC (16.2–19.0 mcd) and is placed at 17.1 mcd in agreement with planktonic foraminiferal data (see "Planktonic Foraminifers").
Pliocene assemblages consist mainly of reticulofenestrids, sphenoliths, and discoasterids. Helicoliths belonging to the genus Amaurolithus (Amaurolithus delicatus and Amaurolithus primus) are common, and ceratholiths belonging to the genus Ceratolithus (Ceratolithus rugosus) are rare. The middle and upper Pliocene assemblages are dominated by small placoliths (2–4 µm), mainly small Reticulofenestra spp., and Pseudoemiliania lacunosa (Cores 208-1267A-3H through 5H). D. brouweri, Discoaster brouweri var. triradiatus, Discoaster pentaradiatus, Discoaster surculus, Discoaster tamalis, and Discoaster asymmetricus are consistently present in the middle–upper Pliocene (17.1–25.6 mcd). The middle/lower Pliocene boundary is placed at 25.6 mcd in agreement with the planktonic foraminiferal data. An expanded lower Pliocene section is present between 25.6 and 84.2 mcd (Sections 208-1267A-5H-4 through 8H-CC), corresponding to Zones CN11 and CN10 (NN15–NN13). The discoasterid assemblage is characterized by D. surculus, D. pentaradiatus, Discoaster variabilis gr., A. delicatus, and A. primus and by common Scyphosphaera spp. The Miocene/Pliocene (M/P) boundary is well constrained between Section 208-1267A-8H-CC (83.5 mcd) and Sample 9H-1, 120 cm, (85.7 mcd), based on the presence of the marker Ceratolithus acutus in Sections 9H-1 and 9H-2 together with very rare specimens of Ceratolithus larrymayeri. Both species have distinct short ranges that straddle the M/P boundary in the equatorial Atlantic Ocean and Mediterranean Seas (Raffi et al., 1998).
Uppermost Miocene sediments could be placed in the interval encompassing Subzones CN10a–CN8b, but the absence of the marker species Discoaster quinqueramus and Discoaster berggrenii prevented the recognition of the Zone CN10/CN9 (NN12/NN11) and Subzone CN9a/Zone CN8 (NN11/NN10) boundaries. The uppermost Miocene ceratolith marker Nicklithus amplificus occurs between Samples 208-1267A-10H-2, 40 cm, and 10H-5, 40 cm (95.5–100.8 mcd), placing these sediments in Subzone CN9bB. The lowermost occurrence of Amaurolithus spp. between Samples 208-1267A-10H-7, 10 cm, and 10H-7, 100 cm, indicates the Subzone CN9bA/CN9a boundary. Just below this interval, preservation of nannofossils deteriorates and dissolution affects the assemblages.
The marker for Subzone CN8b, Discoaster loeblichii, is present in a short interval with a partially dissolved assemblage in Section 208-1267A-10H-7. The sediments in Core 208-1267A-11H contain an unconformity marked by reworked material because assemblages typical for several upper Miocene zones (CN8a, CN7, and CN3–CN2) are present in a few samples in the upper five sections of the core between intervals barren of nannofossils. Assemblages of lower Miocene Subzone CN1c (NN2) occur in Sections 208-1267A-11H-6, 11H-7, and 11H-CC. Within Core 208-1267A-12H, nannofossil assemblages occur in scattered intervals, are strongly dissolved, and do not contain diagnostic markers. The rare species present (Dictyococcites bisectus, Sphenolithus predistentus, Sphenolithus moriformis, and Cyclicargolithus spp.) indicate a possible Oligocene age. The uppermost occurrence (top [T]) of Reticulofenestra umbilicus is between Samples 208-1267A-13H-3, 110 cm, and 13H-4, 110 cm (129.1–130.6 mcd), indicating an early Oligocene age. The T of Ericsonia formosa is between Section 208-1267A-13H-CC and Sample 14H-1, 40 cm (134.4–136.5 mcd). The assemblages in these samples mainly consist of R. umbilicus, Isthmolithus recurvus, Dictyococcites spp., Reticulofenestra dictyoda, Discoaster tani, and Discoaster deflandrei. Section 208-1267A-14H-CC (145.9 mcd) is problematic because of dissolution and reworking and might be either lower Oligocene or upper Eocene.
The uppermost nonreworked occurrences of the last Paleogene representatives of the rosette-shaped discoasters Discoaster saipanensis and Discoaster barbadiensis are between Section 208-1267A-14H-CC and Sample 15H-1, 76 cm (145.8–146.9 mcd), and ~1 m of upper Eocene sediment might be present in the uppermost part of Core 15H. The absence of I. recurvus and Calcidiscus protoannulus, however, indicates that we cannot recognize the E/O boundary and that most of the upper Eocene is not present. The T of Chiasmolithus grandis (37.1 Ma) between Samples 208-1267A-15H-1, 76 cm, and 15H-2, 100 cm (146.9–148.6 mcd), suggests a possible middle Eocene age for this interval, but most of the middle Eocene is missing. Below ~149 mcd, the middle through lower Eocene Zones NP16–NP10 (CP13–CP9) were recognized. Nannofossils are abundant throughout this interval, and preservation varies from moderate to good with dissolved and overgrown discoasterids and Tribrachiatus orthostylus. The assemblages mainly consist of the marker species of the lower Eocene zones including abundant T. orthostylus, Discoaster lodoensis, D. barbadiensis, D. saipanensis, Sphenolithus radians, and common Discoaster diastypus.
The P/E boundary (231.5 mcd) is characterized by the lowermost occurrences of Rhomboaster cuspis and Rhomboaster calcitrapa. Poorly preserved specimens of Rhomboaster occur between Samples 208-1267A-22H-7, 20 cm, and 22H-7, 26 cm (231.45–231.51 mcd). The 10-cm interval directly above the P/E boundary is barren of calcareous nannofossils. The uphole decrease in relative abundance of Fasciculithus, which is relatively common in the uppermost Paleocene, occurs where Zygrhablithus bijugatus increases uphole in relative abundance between Samples 208-1267A-22H-6, 60 cm, and 22H–6, 105 cm (230.35–230.80 mcd). The uppermost occurrence of fasciculiths is between Samples 208-1267A-22H-4, 40 cm, and 22H-6, 10 cm (227.1–229.8 mcd). Specimens belonging to the Rhomboaster-Tribrachiatus plexus are poorly preserved because of calcite recrystallization. Overgrowth of specimens of the Rhomboaster-Tribrachiatus plexus hampered identification of Tribrachiatus contortus and Tribrachiatus bramlettei. Thus, the lowermost occurrence (bottom [B]) of T. orthostylus (between Samples 208-1267A-20H-5, 30 cm, and 20H-6, 30 cm; 207.2–208.3 mcd) and the B of D. diastypus (between Samples 21H-4, 20 cm, and 21H-5, 30 cm; 215.4–217.0 mcd), the marker of the base of Subzone CP9a, have been used to approximate the Subzone CP9b/CP9a (NP11/NP10) and Zone NP10/NP9 boundaries.
The major components of the upper Paleocene assemblages are Discoaster spp. Toweius spp., Coccolithus pelagicus, Prinsius spp., Chiasmolithus spp., Sphenolithus spp., Fasciculithus spp., Heliolithus spp., and Ericsonia spp. Nannofossil assemblages are generally diverse and moderately to well preserved. Most of the important primary and secondary markers (Table T5) of the upper Paleocene are present from the top of Core 208-1267A-22H through the top of Core 29H (~231.5–296.7 mcd). The B of Heliolithus kleinpellii between Section 208-1267A-26X-CC and Sample 27X-1, 41 cm (277.5–278.5 mcd), indicates the presence of the PBE.
The boundary between the upper and lower Paleocene can be approximated with the B of Sphenolithus primus between Section 208-1267A-28X-CC and Sample 29X-1, 23 cm (294.8–296.7 mcd), and is placed at 296.6 mcd, in agreement with planktonic foraminiferal data. In the lower Paleocene, the absence of Ellipsolithus macellus in the lower part of its range prevents the recognition of the Zone CP3/CP2 (NP4/NP3) boundary. E. macellus has its lowermost continuous occurrence in Zone CP5 (NP6). Reworked Cretaceous specimens occur from Cores 208-1267A-25H-CC through the middle part of 31X and from Sections 208-1267B-26X-CC through the middle part of 32X-CC (~267–295 mcd).
The lowermost Paleocene is characterized by moderately well preserved assemblages. The B of Cruciplacolithus tenuis s.s. (64.5 Ma) and the B of Cruciplacolithus primus (64.8 Ma) occur between Samples 208-1267A-30X-5, 20 cm, and 30X-6, 60 cm (312.9–314.8 mcd), and 31X-1, 99 cm, and 31X-2, 60 cm (318.7–319.3 mcd), respectively. The assemblages are mainly composed of Prinsius dimorphosus, C. pelagicus, Neochiastozygus spp., Cruciplacolithus spp., and Zeugrhabdothus sigmoides. The K/P boundary interval is marked by a mass extinction of Cretaceous nannofossil taxa, together with a significant increase in the abundance of Thoracosphaera spp., the B of Biantholithus sparsus (between Samples 208-1267A-31X-3, 68 cm, and 31X-3, 69 cm; 320.38–320.39 mcd), and the co-occurrence of Markalius inversus and Cyclagelosphaera reinhardtii.
The upper Maastrichtian nannofossil assemblages (Zones CC26–CC25 and NC23–NC22–NC21) show dissolution and fragmentation, and Micula staurophora, Micula murus, Prediscosphaera grandis, Lithraphidites quadratus, Lithraphidites carniolensis, Arkhangelskiella cymbiformis, Eiffellithus turriseiffelii, and Watznaueria barnesae are the major components. The B of Micula prinsii (which occurs in Zone CC26) is between Sample 208-1267A-31X-7, 133 cm, and Section 31X-CC (327.0–327.3 mcd). The B of M. murus is between Samples 208-1267A-32X-3, 40 cm, and 32X-5, 100 cm (332.3–335.91 mcd), and that of L. quadratus occurs between Section 208-1276B-35X-CC and Sample 36X-1, 33 cm (358.3–358.5 mcd).
Planktonic foraminifers were examined in all core catcher samples from Holes 1267A and 1267B and in additional samples from the cores through such critical intervals as the Pliocene/Pleistocene, M/P, P/E, and K/P boundary intervals (Tables T7, T8). The preservation and abundance vary throughout the record. Miocene and Oligocene samples between 67.1 and 182.6 mcd (Sample 208-1267A-7H-3, 32–34 cm, through Section 208-1267B-18H-CC) show severe dissolution, with Section 208-1267A-12H-CC being barren. Paleocene–Eocene assemblages are well preserved. Preservation deteriorates in the Maastrichtian (321.3–337.1 mcd; Sample 208-1267A-32X-4, 10–11 cm, through Section 208-1267B-33X-CC). Reworking is common in the Pleistocene (0–18 mcd) and from the middle Miocene through the uppermost lower Eocene (108–177 mcd).
Sample 208-1267A-1H, 0–1 cm (0.01 mcd), contains specimens of the Pliocene species Globigerinoides extremus, indicating reworking and/or downslope transport. Pleistocene assemblages in Cores 208-1267A-1H and 208-1267B-1H through 2H (0.6–12.3 mcd) consist of a mixture of well-preserved subtropical and temperate planktonic foraminifers. Common species are Globorotalia crassaformis, Globorotalia truncatulinoides, Globorotalia tumida, Globoconella inflata, Globigerinoides ruber, Globigerinoides sacculifer, Globigerina (Zeaglobigerina) rubescens, Globigerinella siphonifera, Hirsutella scitula, and Neogloboquadrina pachyderma (dextral). Cursory sampling in Cores 208-1267A-1H and 2H and 208-1267B-1H and 2H indicates that the presence of Pliocene planktonic foraminifers in Pleistocene sediments is largely restricted to an interval near the mudline. Thus, the Pliocene/Pleistocene boundary is provisionally approximated by the uppermost in situ occurrence of G. extremus between Samples 208-1267A-2H-5, 32–34 cm (15.9 mcd), and 2H-7, 32–34 cm (18.4 mcd), and is placed at 17.1 mcd, in agreement with calcareous nannofossil data (see "Calcareous Nannofossils").
Pliocene tropical/subtropical age-diagnostic taxa are missing because the environmental conditions were temperate. G. crassaformis, Globoconella puncticulata, Globoconella conomiozea, Globoconella conoidea, and G. inflata dominate the assemblage. Data from this site confirm that the uppermost occurrences of G. conomiozea and G. conoidea are diachronous, as reported by Boersma (1984). Although warm-water species are generally rare, G. ruber, G. sacculifer, and Globigerinoides trilobus are present throughout the Pliocene. The base of Zone PL6 is approximated by the uppermost appearance of Globoturborotalita woodi between Samples 208-1267A-3H-3, 32–34 cm (25.1 mcd), and 3H-5, 32–34 cm (28.1 mcd). This datum and the uppermost appearances of Globigerina decoraperta (2.7 Ma) between Samples 208-1267A-3H-3, 32–34 cm (25.1 mcd), and 3H-5, 32–34 cm (28.1 mcd), are used to approximate the middle/upper Pliocene boundary, in agreement with the calcareous nannofossil data.
The base of Zone PL3 and the lower/middle Pliocene boundary were approximated by the uppermost occurrence of Neogloboquadrina acostaensis between Section 208-1267B-5H-CC (45.8 mcd) and Sample 208-1267A-5H-5, 32–34 cm (48.6 mcd). The M/P boundary (B of Sphaeroidinella dehiscens and Globigerinoides conglobatus) is between Sections 208-1267A-8H-CC (83.5 mcd) and 9H-CC (92.1 mcd).
Uppermost Miocene Subzone M13a and the Subzone M13b/Zone M14 boundary have been recognized. The upper Miocene sequence from 5.3 to 8.94 Ma seems to be complete despite the rapidly deteriorating preservation downhole. A zonation and age estimate of Miocene sediments older than 8.94 Ma, defined by the B of G. extremus between Sample 208-1267A-10H-6, 32–34 cm (101.8 mcd), and Section 10H-CC (104.0 mcd), is impossible because of the strong dissolution. Sediments deposited between 8.9 and 23.1 Ma are condensed in only 14 m, suggesting the presence of an "unconformity" that is placed in Core 208-1267A-11H based on nannofossil evidence (see "Calcareous Nannofossils"). Sections 208-1267B-11H-CC and 12H-CC are largely barren, containing rare reworked middle Eocene acarininids and morozovellids.
The transition from the lower Miocene into the upper Oligocene could not be recognized with confidence using planktonic foraminifers because of dissolution, and the entire Oligocene sequence is condensed in 30 m. The intense carbonate dissolution extends from the middle to lower Miocene well into the Oligocene, and the highest Oligocene sample identified with confidence is Section 208-1267B-13H-CC (128.5 mcd). The poorly preserved assemblage in this sample consists solely of dissolution-resistant taxa such as Subbotina angiporoides, Globorotalides suteri, Catapsydrax spp., and Globigerina euapertura. The presence of S. angiporoides constrains this sample to lower Oligocene Zones P18 and P19 (>30 Ma), indicating that the upper Oligocene is not present.
Sections 208-1267A-14H-CC (145.9 mcd) and 208-1267B-15H-CC (150.0 mcd) are problematic because they contain assemblages that are winnowed and highly fragmented. The presence of Globigerinatheka spp. and the absence of Acarinina spp. may indicate that this assemblage belongs to Zone P15, but the sedimentological character of this sample suggests reworking comparable to that seen in the lower Oligocene at Site 1266. Moreover, the absence of uppermost Eocene marker taxa indicates that the E/O boundary is not preserved, in agreement with the nannofossil data.
The close proximity (~10 m) of the T of Globigerinatheka index (34.3 Ma) and the T of Morozovella aragonensis (43.6 Ma) points to the presence of a highly condensed interval or unconformity; the latter is indicated by the more detailed nannofossil data that indicate that most of the upper and upper middle Eocene is not represented in the sedimentary record. Intense dissolution and a dearth of tropical marker taxa hindered precise age determination for Section 208-1267A-15H-CC (155.6 mcd), but the co-occurrence of rare diminutive specimens of M. aragonensis and Globigerinatheka kugleri constrains this sample to lower–middle Eocene Zones P10 and P11 (43.6–49.0 Ma).
Although preservation improves downhole, the assemblages in Sections 208-1267A-16H-CC (167.3 mcd) and 17H-CC (177.7 mcd) suffer from varying degrees of dissolution and minor amounts of reworking. Primary constituents of these moderately preserved assemblages are Morozovella caucasica, M. aragonensis, Acarinina spinuloinflata, and "Globigerinatheka" senni, as well as rare specimens of Subbotina inaequispira and Turborotalia frontosa. Section 208-1267A-16H-CC is loosely assigned to Zones P9 and P10, whereas Section 17H-CC is assigned to the uppermost lower Eocene (Zone P9), in agreement with calcareous nannofossil data.
Preservation improves significantly downhole. Section 208-1267B-18H-CC (182.6 mcd) contains common M. aragonensis and M. caucasica but no Acarinina bullbrooki and A. spinuloinflata. This faunal association is indicative of Zone P8. Sections 208-1267A-18H-CC (188.9 mcd) and 208-1267B-19H-CC (193.3 mcd) contain rare specimens of both Morozovella formosa and M. aragonensis, indicating that this interval belongs to Zone P7. Other taxa in these assemblages include Morozovella lensiformis, Morozovella gracilis, Morozovella subbotinae, Acarinina coalingensis, Acarinina soldadoensis, and Igorina broedermanni.
The combination of the presence of M. lensiformis and the absence of M. aragonensis in Sections 208-1267A-19H-CC and 208-1267B-20H-CC qualifies this interval (199.1–205.1 mcd) as Subzone P6b. Sections 208-1267A-20H-CC through 208-1267B-21H-CC (209.5–216.3 mcd) are assigned to Subzone P6a. The general scarcity of Morozovella velascoensis in the lowermost Eocene of this region makes recognition of the P5/P6a zonal boundary difficult. Hence, the upper part of the Morozovella acuta stratigraphic range is substituted to approximate the top of Zone P5. The use of this alternative datum places the top of Zone P5 between Sections 208-1267B-21H-CC (216.3 mcd) and 208-1267A-21H-CC (221.0 mcd) at ~219 mcd.
The P/E boundary interval spans Zone P5. Investigation of six closely spaced (~12 cm) samples across the clay layer that marks the P/E boundary shows that preservation decreases downhole through the lowermost Eocene into the clay layer. Planktonic foraminifers are virtually absent between 231.37 and 231.53 mcd (Samples 208-1267A-22H-7, 12–13 cm, through 28–29 cm). Intense dissolution has left only extremely rare specimens of A. soldadoensis, A. coalingensis, Acarinina "chascanona," and M. subbotinae. Preservation improves and the relative abundance of planktonic foraminifers increases significantly in Sample 208-1267A-22H-7, 37–38 cm (231.62 mcd). This moderately preserved assemblage is composed of morozovellids, acarininids, subbotinids, and rare globanomalinids. The benthic extinction event that demarcates the P/E boundary (231.53–231.62 mcd) is correlative with this change in preservation. Much like other P/E boundary records recovered during Leg 208, the Site 1267 record contains no M. velascoensis or related "excursion" taxa (e.g., Kelly et al., 1996). The bottom of this critical interval coincides with the base of Zone P5 in the uppermost Paleocene, is delimited by the uppermost occurrence of Globanomalina pseudomenardii between Sections 208-1267A-22H-CC (232.9 mcd) and 208-1267B-23H-CC (238.2 mcd), and is placed at ~236 mcd.
Preservation among upper Paleocene assemblages is variable but generally moderate. All the standard Paleocene biozones are recognized in the recovered section. The base of Subzone P4c (56.5 Ma), as delimited by the B of A. soldadoensis, falls between Sections 208-1267A-24H-CC (254.2 mcd) and 208-1267B-25H-CC (261.4 mcd) at an estimated depth of ~258 mcd (Fig. F19). Sections 208-1267A-26X-CC (277.5 mcd) and 208-1267B-27X-CC (278.3 mcd) contain a relatively high abundance of Igorina tadjikstanensis, indicative of the mid-Paleocene biotic event in the lower part of Biozone P4a.
The Subzone P3b/P4a boundary is marked by the B of G. pseudomenardii between Sections 208-1267B-28X-CC (288.1 mcd) and 208-1267A-28X-CC (294.8 mcd) at an estimated depth of ~291 mcd. The boundary between the upper and lower Paleocene (Danian) is correlative to the base of Subzone P3a, marked by the B of Morozovella angulata between Sections 208-1267B-29X-CC (296.6 mcd) and 208-1267A-29X-CC (305.6 mcd); a placement of this boundary at 296.6 mcd would best agree with calcareous nannofossil data (see "Calcareous Nannofossils"). The base of Zone P2, based on the B of Praemurica uncinata, is between Sections 208-1267A-29X-CC (305.6 mcd) and 208-1267B-30X-CC (306.9 mcd), at ~306.21 mcd. Zone P2 is underlain conformably by Subzone P1c based on the B of Praemurica inconstans and the B of Globanomalina compressa between Sections 208-1267B-30X-CC (306.9 mcd) and 31X-CC (315.8 mcd).
Core catcher samples bracketing the K/P boundary were supplemented by sampling in Core 208-1267A-31X. Assemblages are generally moderately well preserved, although some Maastrichtian faunas exhibit strong dissolution.
The base of Subzone P1b, delimited by the B of Subbottina triloculinoides, is tentatively placed at 318.95 mcd (Fig. F19), suggesting that this subzone is much more expanded than it is in Hole 1262B. The base of Subzone P1a is tentatively placed between Samples 208-1267A-31X-3, 21–30 cm (320.0 mcd), and 50–51 cm (320.2 mcd), suggesting that Subzone P1a is also more expanded at Site 1267 than at Site 1262. Large, reworked specimens of Maastrichtian foraminifers are present in Zone P (320.2–320.4 mcd), and Zone P0 was not recognized.
The Danian "dwarfed" assemblages in Subzones P1a and P1b show fragmentation and some overgrowth, and they consist primarily of diminutive forms of Praemurica taurica, Parasubbotina pseudobulloides, Parasubbotina eobulloides, Globanomalina planocompressa, Globoconusa daubjergensis, Eoglobigerina eobulloides, Guembelitria cretacea, Woodringinia hornerstownensis, Chiloguembelina midwayensis, and Chiloguembelina morsei.
The presence of Abathomphalus mayaroensis, Contusotruncana contusa, and Heterohelix striata in Sample 208-1267B-31X-3, 74–75 cm (320.4 mcd), signifies the Maastrichtian. The K/P boundary (Fig. F19) is situated between Samples 208-1267A-31X-3, 70–71 cm, and 74–75 cm (320.40–320.44 mcd). Assemblages of the A. mayaroensis Zone contain Globotruncana falsostuarti, Globotruncana aegyptiaca, Pseudotextularia elegans, and Racemiguembelina fructicosa, in addition to the species mentioned above, and occur down through 367.97 mcd in Section 208-1267B-36X-CC at the bottom of the hole.
All core catcher samples from Hole 1267A, mudline samples from Holes 1267A and 1267B, Sections 208-1267B-1H-CC and 11H-CC through 36X-CC, and additional samples in the P/E and K/P boundary intervals were semiquantitatively investigated for benthic foraminifers (Table T9).
In intervals above 52 mcd, between 193.0 and 267.2 mcd, and below 278.3 mcd, benthic foraminifers are rare, strongly outnumbered by planktonic foraminifers, and generally well preserved. Between 52.0 and 193.0 mcd (Section 208-1267A-5H-CC through Sample 19H-3, 10–11 cm) and between 267.2 and 278.3 mcd (Sections 208-1267A-25H-CC through 208-1267B-27X-CC), samples have common to abundant benthic foraminifers with highly variable preservation because of dissolution, downslope transport, and reworking. Indicators of downslope transport are abundant large siphonodosariid species (e.g., Siphonodosaria pomuligera), large nodosariids, large specimens of Gyroidinoides spp., Oridorsalis umbonatus, Globocassidulina subglobosa, and the agglutinant species Spiroplectammina spectabilis and Vulvulina spinosa. Abraded specimens of Cibicidoides havanensis, Cibicidoides grimsdalei, and Cibicidoides eocaenus are common in samples between 92.1 and 160.7 mcd (Sections 208-1267A-9H-CC through 208-1267B-16H-CC), as in coeval samples from Site 1266. Plectofrondicularia paucicostata occurs in samples at 145.9 mcd (Section 208-1267A-14H-CC) and 188.9 mcd (Section 18H-CC) and is abundant in the former. Section 208-1267B-11H-CC (108.6 mcd) and Sample 208-1267A-22H-7, 28–29 cm (231.5 mcd), are barren.
Benthic foraminiferal assemblages from Site 1267 indicate deposition at lower abyssal depths (>3000 m) between 0 and 243.3 mcd (Sample 208-1267B-1H, 0–1 cm, through Section 208-1267A-23H-CC). Between 249.9 and 288.1 mcd (Sections 208-1267B-24H-CC through 28X-CC), assemblages indicate deposition at transitional upper to lower abyssal depths, and below 296.7 mcd through the bottom of the hole at 368.0 mcd, they indicate lowermost upper abyssal depths (~3000 m). The paleodepths for samples from Site 1267 are not significantly different from those of coeval samples at Site 1262.
Assemblages in samples between 0 and 104.0 mcd (Sample 208-1267B-1H-1, 0–2 cm, through Sections 208-1267A-10H-CC) resemble those presently living in the Walvis Ridge area at depths below ~4200 m (Schmiedl et al., 1997), including common Nuttallides umbonifera, Epistominella exigua, Alabaminella weddellensis, Pyrgo spp., Pullenia spp., O. umbonatus, Stainforthia complanata, and G. subglobosa. Cibicidoides wuellerstorfi is present through the interval, having its lowermost occurrence in Section 208-1267A-10H-CC (104.0 mcd). In both mudline samples, the phytodetritus-consuming species E. exigua and A. weddellensis are common to abundant, indicating a strong influence of seasonal productivity. Through the uppermost 104 mcd, the relative abundance of phytodetritus-consuming species and N. umbonifera (abundant in Section 208-1267A-1H-CC; 3.1 mcd), an indicator of the presence of Antarctic Bottom Water, fluctuate strongly. At present, this species is common to abundant to the north of Walvis Ridge below depths of ~4200 m (Schmiedl et al., 1997). The fluctuations in relative abundances in this interval may indicate fluctuations in surface productivity and bottom water mass characteristics.
The in situ components in the assemblages between 108.6 and 139.5 mcd (Sections 208-1267B-11H-CC through 14H-CC) are thin walled and well preserved and consist of taxa common in abyssal Oligocene through lower–middle Miocene assemblages such as N. umbonifera, E. exigua, G. subglobosa, Gyroidinoides spp., Pullenia spp., and common Siphonodosaria spp., pleurostomellid, and unilocular taxa. Nonion havanense and A. spissiformis have their uppermost occurrences in this interval. Reworked components include C. grimsdalei, C. eocaenus, and C. havanensis, S. pomuligera, V. spinosa, and S. spectabilis.
Sections 208-1267A-14H-CC and 208-1267B-15H-CC (145.9–150.0 mcd) contain common Nuttallides truempyi, in addition to the taxa listed above as in situ components, with assemblages typical of upper to middle Eocene abyssal assemblages. Some of the N. truempyi specimens are large and abraded and thus probably reworked; other reworked components include C. grimsdalei, C. eocaenus, and C. havanensis, and P. paucicostata in Section 208-1267A-14H-CC (145.9 mcd). Abyssamina poagi and Abyssamina quadrata have their uppermost occurrence in Section 208-1267B-15H-CC (150.0 mcd).
Aragonia aragonensis has its uppermost appearance in Section 208-1267A-15H-CC (155.6 mcd). Assemblages between 155.6 and 231.5 mcd (Section 208-1267A-15H-CC through Sample 22H-7, 20–21 cm) contain the typical lower through lower middle Eocene assemblages occurring over a large depth range in the Atlantic Ocean (Clark and Wright, 1984; Müller-Merz and Oberhänsli, 1991; Thomas and Shackleton, 1996). These assemblages have been somewhat affected by dissolution, reworking, and downslope transport between 155.6 and 193.0 mcd (Section 208-1267A-15-H-CC through Sample 19H-3, 10–11 cm) (Table T9). The assemblages are characterized by the presence of A. aragonensis, Alabamina dissonata, and common to abundant small smooth-walled species of Abyssamina, Quadrimorphina, and Clinapertina; the occurrence of small smooth-walled buliminid species (e.g., Bulimina kugleri and Bulimina simplex); and small specimens of N. truempyi, O. umbonatus, A. spissiformis, and N. havanense. Tappanina selmensis and Siphogenerinoides brevispinosa vary strongly in relative abundance, and unilocular, siphonodosariid, laevidentalinid, and pleurostomellid taxa are present. Samples in relatively clay rich intervals at 193.0 mcd (Sample 208-1267A-19H-3, 10–11 cm) and 205.0 mcd (Sample 20H-3, 108–109 cm) contain assemblages with relatively low species richness, which are dominated by Clinapertina complanata and A. poagi.
In the lowermost part of this interval (231.2–231.5 mcd; Samples 208-1267A-22H-6, 148–149 cm, through 22H-7, 20–21 cm), species richness is extremely low and long-lived unilocular and laevidentalinid taxa are absent. Similar assemblages have been described from immediately after the P/E benthic foraminiferal extinction event (BEE) (Müller-Merz and Oberhänsli, 1991; Thomas and Shackleton, 1996) and occur at other Leg 208 sites. Minute specimens of A. quadrata, B. kugleri, Clinapertina inflata, Quadrimorphina profunda, and small specimens of O. umbonatus and N. truempyi are common to abundant. The latter two species dominate most samples, but the lowermost sample is dominated by A. quadrata.
The BEE, including the uppermost appearance of Stensioeina beccariiformis, occurs between Samples 208-1267A-22H-7, 28–29 cm, and 22H-7, 37–38 cm (231.53-231.62 mcd), and between Sections 208-1267B-22H-CC and 23H-CC (227.3–238.2 mcd). Sample 208-1267A-22H-7, 28–29 cm (231.53 mcd), immediately above the lithologic contact between clay-rich material and underlying carbonate-rich material, is barren.
Samples between 231.6 and 249.9 mcd (Sample 208-1267A-22H-7, 37–38 cm, through Section 208-1267B-24H-CC) contain a typical preextinction Paleocene species-rich abyssal assemblage with common S. beccariiformis, Cibicidoides hyphalus, Pullenia coryelli, Bulimina thanetensis, and Aragonia velascoensis, large agglutinant taxa such as Clavulinoides amorpha, Clavulinoides trilatera, and Marssonella oxycona, as well as large smooth-walled Gyroidinoides species such as Gyroidinoides beisseli and Gyroidinoides globosus, all of which became extinct during the BEE. S. brevispinosa and Rectobulimina carpentierae are present in most samples at highly variable relative abundances, as in coeval assemblages at Sites 1262 and 1266.
The assemblages change gradually in species composition between 249.9 and 286.5 mcd (Sections 208-1267B-24H-CC through 208-1267A-27X-CC), with Abyssamina and Clinapertina species and B. thanetensis becoming less common downhole, and Nuttallinella florealis, Nuttallinella sp., and various agglutinants such as Rhizammina spp. becoming more common. Spiroplectammina dentata has its local uppermost appearance in this interval, and Tritaxia havanensis and B. thanetensis have their lowermost occurrences. Benthic foraminiferal assemblages show a coeval, similar faunal change (including the B of B. thanetensis) at Site 1262 and at ODP Sites 689 and 690 at Maud Rise (Thomas, 1990), which may be the benthic foraminiferal expression of the mid-Paleocene biotic event, or it may have occurred slightly earlier. At Sites 1262 and 1267, the paleodepth changed in the middle Paleocene and the assemblages were affected by dissolution, reworking, and downslope transport (Fig. F19). These factors may have contributed to the faunal change at Sites 1262 and 1267, but widespread paleoceanographic changes may also have played a role.
The benthic foraminiferal assemblages between 296.6 mcd and the bottom of the hole at 368.0 mcd (Sections 208-1267A-28X-CC through 208-1267B-36X-CC) closely resemble assemblages in the Velasco Formation in Mexico, where many of the species present at Site 1267 were first described (Alegret and Thomas, 2001). Common to abundant species include some that range through the Paleocene, such as S. beccariiformis, Clavulinoides spp., G. beisseli, G. globosus, Gyroidinoides quadratus, M. oxycona, and Gaudryina pyramidata, and long-ranging species such O. umbonatus and N. truempyi. Assemblages between 320.2 and 320.4 mcd (Samples 208-1267A-31X-3, 50–51 cm, through 74–75 cm), across the K/P boundary, document that benthic foraminifers at Site 1267 did not suffer significant extinction at that time, as observed at many other sites. As at Site 1262, the uppermost appearance of Praebulimina reussi occurs at the K/P boundary in the shipboard data, but it is not well documented whether the species disappeared globally.
