2. C N , ODP L 198 S 1208 (S R , N O 1
44
Bralower, T.J., Premoli Silva, I., and Malone, M.J. (Eds.) Proceedings of the Ocean Drilling Program, Scientific Results Volume 198 2. CENOZOIC CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY , ODP LEG 198 SITE 1208 (SHATSKY RISE, NORTHWEST PACIFIC OCEAN) 1 Paul R. Bown 2 ABSTRACT Ocean Drilling Program Site 1208 was drilled on the Central High of Shatsky Rise, and a highly expanded Neogene section (320 m), an ex- tremely condensed Paleogene fragment (6.01 m), and a short Upper Cretaceous sequence (48.44 m) resting unconformably on Albian sedi- ments were recovered. This paper presents the Cenozoic nannofossil biostratigraphy of Site 1208, focusing on the expanded Neogene sec- tion, comprising an apparently continuous middle Miocene–Holocene succession (Zones CN5–CN15), in which nannofloras are diverse and abundant throughout, and a fragmentary Paleogene–lower Miocene section (Zones CP8 to CN1c–CN2), which incorporates short fragments of the Paleocene/Eocene (Zones CP8–CP11) and Eocene/Oligocene (Zone CP16) boundary intervals bounded by three main unconformi- ties. Two new species, Sphenolithus arthurii and Fasciculithus fenestrella- tus, are described. INTRODUCTION Shatsky Rise is a moderately sized large igneous province that was erupted episodically at a hotspot triple junction intersection between 146 and 133 Ma (Tithonian–Valanginian) at equatorial latitudes (Bral- ower, Premoli Silva, Malone, et al., 2002). Site 1208 is located on the previously undrilled Central High (Fig. F1) at lower bathyal water F1. Bathymetric map of Shatsky Rise, p. 14. 155°E 160° 30° 35° 165° 170° 40° N 0 500 km 305 and 1211 306 and 1214 1212 Sliter Basin Helios Basin 1213 1209 1210 50 1207 1208 Shatsky Rise Magellan Manihiki Ontong Java Mid-Pacific Mts Hess Southern High Central High Northern High Ojin Rise seamounts Papanin Ridge 3000 mbsl 4000 mbsl 5000 mbsl Pacific Ocean 1 Bown, P.R., 2005. Cenozoic calcareous nannofossil biostratigraphy, ODP Leg 198 Site 1208 (Shatsky Rise, northwest Pacific Ocean). In Bralower, T.J., Premoli Silva, I., and Malone, M.J. (Eds.), Proc. ODP, Sci. Results, 198, 1–44 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/ publications/198_SR/VOLUME/ CHAPTERS/104.PDF>. [Cited YYYY- MM-DD] 2 Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom. Correspondence author: [email protected] Initial receipt: 22 February 2004 Acceptance: 23 March 2005 Web publication: 15 September 2005 Ms 198SR-104
Transcript of 2. C N , ODP L 198 S 1208 (S R , N O 1
Bralower, T.J., Premoli Silva, I., and Malone, M.J. (Eds.)Proceedings of the Ocean Drilling Program, Scientific Results Volume 198
2. CENOZOIC CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY, ODP LEG 198 SITE 1208 (SHATSKY RISE, NORTHWEST PACIFIC OCEAN)1
Paul R. Bown2
ABSTRACT
Ocean Drilling Program Site 1208 was drilled on the Central High ofShatsky Rise, and a highly expanded Neogene section (320 m), an ex-tremely condensed Paleogene fragment (6.01 m), and a short UpperCretaceous sequence (48.44 m) resting unconformably on Albian sedi-ments were recovered. This paper presents the Cenozoic nannofossilbiostratigraphy of Site 1208, focusing on the expanded Neogene sec-tion, comprising an apparently continuous middle Miocene–Holocenesuccession (Zones CN5–CN15), in which nannofloras are diverse andabundant throughout, and a fragmentary Paleogene–lower Miocenesection (Zones CP8 to CN1c–CN2), which incorporates short fragmentsof the Paleocene/Eocene (Zones CP8–CP11) and Eocene/Oligocene(Zone CP16) boundary intervals bounded by three main unconformi-ties. Two new species, Sphenolithus arthurii and Fasciculithus fenestrella-tus, are described.
INTRODUCTION
Shatsky Rise is a moderately sized large igneous province that waserupted episodically at a hotspot triple junction intersection between146 and 133 Ma (Tithonian–Valanginian) at equatorial latitudes (Bral-ower, Premoli Silva, Malone, et al., 2002). Site 1208 is located on thepreviously undrilled Central High (Fig. F1) at lower bathyal water
F1. Bathymetric map of Shatsky Rise, p. 14.
155°E 160°
30°
35°
165° 170°
40°N
0 500
km
305 and1211
306 and1214
1212
SliterBasin
Helios Basin
1213
1209
1210
50
1207
1208
ShatskyRise Magellan
Manihiki
Ontong Java
Mid-PacificMts
Hess
Southern High
Central High
Northern High
Ojin Rise seamounts
Papa
nin
Rid
ge
3000 mbsl4000 mbsl5000 mbsl
Pacific Ocean
1Bown, P.R., 2005. Cenozoic calcareous nannofossil biostratigraphy, ODP Leg 198 Site 1208 (Shatsky Rise, northwest Pacific Ocean). In Bralower, T.J., Premoli Silva, I., and Malone, M.J. (Eds.), Proc. ODP, Sci. Results, 198, 1–44 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/198_SR/VOLUME/CHAPTERS/104.PDF>. [Cited YYYY-MM-DD]2Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom. Correspondence author: [email protected]
Initial receipt: 22 February 2004Acceptance: 23 March 2005Web publication: 15 September 2005Ms 198SR-104
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 2
depths (3346 m), and drilling was expected to penetrate 785 m of thickNeogene, Paleogene, and Upper Cretaceous units. However, coring atSite 1208 revealed a dramatically different sequence, notably a highlyexpanded Neogene section (320 m), an extremely condensed, incom-plete, Paleogene fragment (6.01 m), and a short Upper Cretaceous se-quence (48.44 m) resting unconformably on Albian sediments, wherethe hole was terminated due to drilling difficulties related to abundantchert (Bralower, Premoli Silva, Malone, et al., 2002).
This report presents the Cenozoic nannofossil biostratigraphy in thesingle hole cored at Site 1208. The expanded Neogene section com-prises an apparently continuous middle Miocene–Holocene successionin which nannofloras are diverse and abundant throughout. Correla-tion with magnetostratigraphy is good and is presented in detail byEvans et al. (this volume). The Paleogene section is thin and con-densed but incorporates short fragments of the Paleocene/Eocene andEocene/Oligocene boundary intervals bounded by three main uncon-formities. Cretaceous nannofossil biostratigraphy is presented in Leesand Bown (this volume). The nannofossil biostratigraphy presentedhere gives greater detail than that in the Leg 198 Initial Reports volume(Bralower, Premoli Silva, Malone, et al., 2002) but does not differ signif-icantly despite increased sampling resolution.
MATERIAL
Drilling at Site 1208 yielded the following succession: 252 m of cyclicupper Miocene–Holocene nannofossil ooze and nannofossil clay withsignificant amounts of diatoms throughout (5%–20%) (Subunit 1A ofBralower, Premoli Silva, Malone, et al., 2002); 60 m of dark orange-brown lower and middle Miocene claystone, nannofossil ooze, andchalk (Subunit 1B of Bralower, Premoli Silva, Malone, et al., 2002); 16 mof highly condensed lower Miocene–Paleocene claystone with phillips-ite (zeolite) and manganese micronodules alternating with orange toyellow-brown nannofossil claystone and ooze (Subunit 1C of Bralower,Premoli Silva, Malone, et al., 2002); and 65 m of pure white Campaniannannofossil ooze and chalk (Unit 2 of Bralower, Premoli Silva, Malone,et al., 2002). The hole was terminated in Albian nannofossil chalk andchert.
METHODS
Calcareous nannofossils were analyzed semiquantitatively using sim-ple smear slides and standard light microscope techniques (Bown andYoung, 1998); abundance and preservation categories are given in TableT1. Biostratigraphy is described with reference to the Cenozoic CP andCN zones of Okada and Bukry (1980). The timescale correlations are af-ter Bralower, Premoli Silva, Malone, et al. (2002).
NANNOFOSSIL RESULTS
Nannofossil results are presented as stratigraphic range charts in Ta-bles T1 and T2 and as age-depth plots in Figures F2, F3, and F4. Thedata used to create the age-depth plots are given in Table T3. Represen-tative images of the nannofossil assemblages are given in Plates P1–P12
T1. Calcareous nannofossil stra-tigraphic range chart, Site 1208, p. 18.
T2. Paleogene–lower Miocene stratigraphic range chart, Site 1208, p. 19.
F2. Age-depth plot of Cretaceous calcareous nannofossil datums, Site 1208, p. 15.
FO E. huxleyi
LO G. omega
FO G. caribbeanica
FO D. brouweri
LO D. tamalis
LO R. pseudoumbilicus
FO C. cristatus
LO D. quinqueramus
FO D. berggrenii
FO Amaurolithus
LO D. hamatus
FO C. coalitus
LO C. premacintyrei
LO H. irregularis
FO B. parca parcaFO B. parca constricta
LO E. eximius
LO U. trif.
FO D. multiradiatus
FO R. bram.FO D. lodo.
S. hetero.
FO D. druggi
0 10
20
80
120
140
160
180
200
220
240
260
280
300
Age (Ma)
Dep
th (
mbs
f)
Neogene Paleogene Cretaceous
20 40 50 60 70 80 90 10030 110
FO R. stavensis
R. umbilicus
acme C. subdistichus
320
340
360
380
400
100
60
40
42.0 m/m.y.
35.1 m/m.y.
25.1 m/m.y.
10.9 m/m.y.
0.6m/m.y.
6.0 m/m.y.
0
F3. Age-depth plot of Neogene calcareous nannofossil datums, Site 1208, p. 16.
8 10 1812 2014 16
FO E. huxleyi
LO P. lacunosa
LO G. omega
FO G. caribbeanica
FO D. brouweri
LO D. pentaradiatusLO D. surculus
LO D. tamalis
FO D. tamalis, D. asymmetricus
LO Amaurolithus
FO C. cristatus
LO D. quinqueramus
FO D. berggrenii
FO Amaurolithus
FO D. hamatusFO C. coalitusLO C. miopelagicus
LO C. premacintyrei LO C. floridanus
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
Age (Ma)
Pleis. Pliocene late Miocene middle Miocene
LO Spheno.
LO R. ps.
22
FO D. druggii
FO S. hetero.LO S. heteromorphus
FO R. pseudo. >7 µm
FO C. calyculusLO D. hamatus
24
320
340
Dep
th (
mbs
f)
early Miocene Ol.
52.4 m/m.y.
35.1 m/m.y.
25.1 m/m.y.
10.9 m/m.y.
0.6 m/m.y.
4.5 m/m.y.
LOR. stavensis
0 2 4 60
F4. Age-depth plot of Paleogene calcareous nannofossil datums, Site 1208, p. 17.
LO acme C. subdistichusLO B. parca constricta
LO U. trif.
FO D. multirad.FO R. bramlettei
FO D. lodoensis
LO S. heteromorphus
LO R. stavensis
FO D. druggii
FO S. heteromorphus
LO S. ciperoensis
LO R. umbilicus
FO acme C. subdistichus
FO I. recurvus
LO R. stavensis
FO R. umbilicus
LO E. eximius
0 10
316
318
320
322
324
326
328
330
Age (Ma)
Dep
th (
mbs
f)
P.Plio. Miocene Eocene
20 30 40 50 60 70 80314
Oligocene Paleog. Cretaceous
6.0 m/m.y.
5.6 m/m.y.
0.6 m/m.y.
0.1m/m.y.
LO C. abisectus
LO C. formosus
LO T. orthostylus
LO D. barbadiensis
T3. Calcareous nannofossil da-tums, ages and depths, p. 20.
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 3
(Neogene: Pls. P1, P2, P3, P4, P5, P6, P7; Paleogene: Pls. P8, P9, P10,P11, P12). All cores were productive apart from a small number of sam-ples from the dark brown claystones of the Paleocene–lower Miocenecondensed interval (Subunit 1C). The middle Miocene–Holocene sec-tion yielded a beautiful succession of rich and abundant nannofossil as-semblages. Preservation improved upsection but was also dependentupon which part of the sedimentary cycles had been sampled. Thedarker, diatom-rich intervals yielded more poorly preserved nannofossilassemblages. Diatoms are common in the smear slides from the middleMiocene–Holocene. The Paleogene condensed interval yielded ex-tremely variable abundances, preservation, and diversity; 8 of 50 sam-ples were barren, and evidence of mixing of assemblage componentswas observed. The Cretaceous samples yielded abundant, moderatelypreserved, and diverse assemblages.
NANNOFOSSIL BIOSTRATIGRAPHY
Miocene–Holocene
Neogene nannofossil biostratigraphy indicates a relatively completestratigraphy with all zones from CN5 through CN15 (middle Miocene–Holocene) identified by their primary zonal fossils. Zones CN1–CN5could not be easily distinguished because of the absence of the markerspecies Sphenolithus belemnos, Helicosphaera ampliaperta, and Discoasterkugleri. In addition, a number of CN subzones could not be recognizeddue to the absence of D. kugleri (Subzone CN5b), Discoaster loeblichii,Discoaster neorectus (Subzone CN8b), and Amaurolithus amplificus (subdi-visions within Zone CN9) and an anomalously low last occurrence (LO)of Triquetrorhabdulus rugosus (Subzone CN10b). The absence of thesezonal and subzonal markers is most likely due to rarity or ecological/biogeographic exclusion rather than significant missing time/sediment.The age-depth plot shows no obvious “benches” or datum event clus-ters that would indicate hiatuses, and the match with magnetostratigra-phy is good (see Fig. F3; Evans et al., this volume). Shipboardplanktonic foraminifer biostratigraphy also indicated a relatively com-plete stratigraphy (Bralower, Premoli Silva, Malone, et al., 2002).
Miocene sediments older than Zone CN5 are more difficult to assignto biozones due to the absence, or rare and sporadic occurrence, of pri-mary marker species, as listed above. Sphenolithus heteromorphus, al-though present, is sporadically distributed, and sphenoliths andHelicosphaera are generally rare throughout the Miocene section. Anumber of secondary lower–middle Miocene datum events are includedon the age-depth plot (Fig. F3) (e.g., the LO of Calcidiscus premacintyrei,the LO of Coccolithus miopelagicus, and the LO of Cyclicargolithus florida-nus), but there is no single solution that honors all the data points.Most likely, the LO of S. heteromorphus is anomalously low because ofecological exclusion of sphenoliths. This interpretation is supported bythe presence of the Zone CN4 discoasters, Discoaster muscicus and Dis-coaster petaliformis (Young, 1998), in Sample 198-1208A-34X-5, 114 cm,and the first occurrence (FO) of large Reticulofenestra pseudoumbilicus(Young, 1998) in Sample 198-1208A-33X-5, 120 cm, which marks thetop of Zone CN4.
P1. Helicosphaeraceae, Pontosphaeraceae, Noelaerhab-daceae, Reticulofenestra, p. 21.
Ret. haqii (4µm) 1208A-27X-CC
R. pseud. (5.0µm) 1208A-27X-CC R. pseud. (6.1µm) 1208A-26X-CC R. pseud. (6.9µm) 1208A-26X-CC R. pseud. (8.4µm) 1208A-23X-CC R. pseud. (11.5µm) 1208A-28X-CC
C. floridan. (10.1µm) 1208A-27X-CC Cy. floridan. (7.5µm) 1208A-32X-CCC. ?abisect. (11.4µm) 1208A-32X-CC Cy. floridan. (9.3µm) 1208A-32X-CC R. bisecta (10.6µm) 1208A-35X-CCC. floridan. 1208A-35X-CC
R. pseud. (7.8µm) 1208A-19H-CC
Ret. haqii (3.1µm) 1208A-18H-CCsmall retics (~1.7µm) 1208A-18H-CC
R. ps. w. grill (9.2µm) 1208A-18H-CC Pseudo. lacunosa 1208A-16H-CC
Ret. haqii (4.3µm) 1208A-16H-CC Ret. haqii (4.1µm) 1208A-14H-CC
Ret. haqii (4.7µm) 1208A-9H-CC
Pseudo. ovata 1208A-9H-CC
Ret. haqii-asanoi (5.4µm) 1208A-7H-CC R. haqii-asanoi (6.3µm) 1208A-6H-CC R. asanoi (6.6µm) 1208A-6H-CC
Ret. minuta (2.8µm) 1208A-5H-CC
Pseudo. lacunosa 1208A-4H-CC
Pont. multipora 1208A-18H-CCPont. discopora 1208A-9H-CC Sy. pulchra 1208A-8H-CC
Hel. carteri 1208A-8H-CC Hel. inversa 1208A-3H-CC Hel. sellii 1208A-13H-5
Pont. discopora 1208A-2H-5
Hel. granulata 1208A-34X-5
Ret. asanoi (6.8µm) 1208A-6H-5 Ret. rotaria 1208A-25X-4
Em. huxleyi 1208A-1H-4
Ca. brasiliensis 1208A-1H-4Rh. clavigera 1208A-1H-4
2µm
19 20 21 22 23 24
31 32 33 34 35 36
37 38 39 40 41 42
1 2 3 4 5 6
Helicosphaeraceae
Pontosphaeraceae
Noelarhabdaceae
Reticulofenestra
7 8 9 10 11 12
13 14 15 16 17 18
25 26 27 28 29 30
Em. huxleyi 1208A-1H-4
P2. Gephyrocapsa, Coccolith-aceae, Calcidiscaceae, p. 23.
Cocco. pelagicus 1208A-30X-CC Cocco. pelagicus 1208A-19H-CC
Calci. leptoporus (6.3µm) 1208A-27X-CC
C. macintyrei (11.2µm) 1208A-24X-CC
Calci. lepto. (8.8µm) 1208A-24X-CC
C. macintyrei (11.2µm) 1208A-32X-CC
C. premacintyrei (11.2µm) 1208A-32X-CC
C. tropicus (8.9µm) 1208A-32X-CC
C. premacintyrei 1208A-33X-CC
C. tropicus (8.8µm) 1208A-21X-CC C. tropicus (7.8µm) 1208A-18H-CC
Calci. leptoporus 1208A-14H-CC C. tropicus (8.7µm) 1208A-13H-CC
small Geph. (2.1µm) 1208A-18H-CCsmall Geph. (2.1µm) 1208A-9H-CC
med. Geph. (4.3µm) 1208A-8H-CC
large Geph. (5.1µm) 1208A-8H-CC
med. Geph. (4.1µm) 1208A-8H-CC
large Geph. (5.0µm) 1208A-8H-CC
small Geph. (2.8µm) 1208A-5H-CC small Geph. (2.9µm) 1208A-4H-CC
med. Geph. (3.8µm) 1208A-4H-CC
small Geph. (2.9µm) 1208A-3H-CC
med. Geph. (4.4µm) 1208A-2H-CC
small Geph. (1.4µm) 1208A-2H-CC
med. Geph. (3.8µm) 1208A-2H-CC med. Geph. (3.8µm) 1208A-1H-CC
oceanica-typeoceanica-type
oceanica-type oceanica-typeoceanica-type oceanica-type
caribbeanica-type
caribbeanica-type caribbeanica-type
Cocc. miopelagicus (15.1µm) 1208A-31X-CC
G. omega (5.0µm) 1208A-5H-CC G. omega (5.3µm) 1208A-4H-CCG. omega (5.2µm) 1208A-1H-CC
C. premacintyrei (11.5µm) 1208A-31X-CC
C. macintyrei (11.7µm) 1208A-26X-CC
large Geph. (5.6µm) 1208A-1H-1
oceanica-type
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
2µm
37 38 39 40 41 42
Calcidiscaceae
Coccolithaceae
P3. Sphenolithaceae, Incertae se-dis, Ceratolithaceae, p. 25.
Am. primus 1208A-26X-CCAm. primus 1208A-25X-CC
Am. delicatus 1208A-24X-CCAm. delicatus 1208A-23X-CC
Am. delicatus 1208A-19H-CC
Minylitha convallis 1208A-27X-CCMinylitha convallis 1208A-28X-CC
holococcolith 1208A-1H-CC
Umb. rotula 1208A-27X-CC
Sph. abies 1208A-25X-CC
Umb. rotula 1208A-30X-CC
Sph. heteromophus 1208A-33X-CC Sph. moriformis 1208A-35X-CC
Sph. predistentus 1208A-35X-CCSph. intercalaris 1208A-35X-CC
Tet. symeonidesii 1208A-14H-CC
Flor. profunda 1208A-7H-CC
Umb. sib. sib. 1208A-5H-CC
Coronocyclus nitescens 1208A-33X-CC
2µm
Umb. jafari 1208A-18H-CC
Am. bizzarus 1208A-22X-5
Cry. mediaperforatus 1208A-24X-CC Cry. mediaperforatus 1208A-32X-CC
Umb. sib. sib. 1208A-2H-CC
Umbell. tenuis 1208A-1H-1
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
37 38 39 40 41
2µm
42
Sphenolithaceae
Incertae sedis
Incertae sedis
Ceratolithaceae
Hol.Umbell.
Cry. mediaperforatus 1208A-33X-CC
P4. Triquetrorhabdulus, Calci-spheres, Discoasteraceae, p. 27.
D. deflandrei 1208A-34X-CCD. deflandrei 1208A-32X-CC
Discoaster exilis 1208A-32X-CC
2µm
Am. primus 1208A-26X-CC Am. primus 1208A-24X-CC
Tr. rugosus 1208A-28X-CC
Am. primus 1208A-21X-CC
Cer. cristatus 1208A-19H-CC Cer. rugosus 1208A-19H-CC Cer. rugosus 1208A-14H-CCCer. cristatus 1208A-1H-CC
calcisphere 1208A-18H-CC calcisphere 1208A-4H-CC
calcisphere 1208A-1H-CC
D. petaliformis 1208A-34X-5D. exilis 1208A-30X-4
Disco. druggii 1208A-35X-3, 149Disc. deflandrei 1208A-35X-3, 149
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17
18 19 20 21 22 23
24 25 26 27
28 29 30 31
2µm
Dicoasteraceae
Triquet. Calcispheres
Disc. deflandrei 1208A-35X-3, 149
P5. Discoasteraceae II, p. 29.
D. variabilis (5) 1208A-29X-CCD. variabilis (6) 1208A-28X-CC
Discoaster variabilis (6) 1208A-29X-CCDiscoaster variabilis (6) 1208A-25X-CC
D. variabilis (6) 1208A-28X-CC
D. challengeri 1208A-23X-CC
D. variabilis (5) 1208A-25X-CC D. variabilis (3) 1208A-26X-CC D. variabilis (7) 1208A-29X-CC
D. challengeri 1208A-27X-CC
D. variabilis 1208A-27X-CC
D. challengeri 1208A-30X-CC
D. surculus 1208A-14H-CC D. surculus 1208A-13H-CC
D. brouweri 1208A-17H-CC
D. surculus 1208A-18H-CC
D. brouweri 1208A-18H-CC
D. surculus 1208A-19H-CC D. surculus 1208A-21X-CC
Discoaster brouweri 1208A-27X-CC
D. challengeri 1208A-30X-CCD. challengeri 1208A-33X-CC
Discoaster calcaris 1208A-29X-2Discoaster. brouweri 1208A-28X-CC Discoaster blackstockiae 1208A-24X-CC
1 2 3 4 5 6
7 8 9 10 11 12
23 24 25 26 27 28
29 30 31 32
2µm
13 14 15 16 17 18
19 20 21 22
33 34 35 36 37 38
D. challengeri 1208A-27X-CC
D. variabilis (6) 1208A-28X-CC D. variabilis (6) 1208A-28X-CC
D. variabilis (6) 1208A-28X-CC
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 4
Paleocene–Lower Miocene
The lower Miocene–Paleocene section is a short (16 m), condensedsection incorporating at least three major hiatuses (Figs. F2, F4). Nan-nofossil biostratigraphy is problematic in places due to mixing of strati-graphically incongruous assemblage components (Table T2). Themixing includes both upsection reworking and downsection bioturba-tion; the latter was prominent in this lithologic unit (Bralower, PremoliSilva, Malone, et al., 2002). Intriguingly, however, the unit appears toincorporate the Paleocene/Eocene boundary and the Eocene/Oligoceneboundary carbonate pulse (e.g., Bralower, Premoli Silva, Malone, et al.,2002; Lyle, Wilson, Janecek, et al., 2002).
The upper Oligocene–lower Miocene section (~1.1 m) is character-ized by low-diversity assemblages dominated by Discoaster deflandreiand C. floridanus. The FOs of Sphenolithus ciperoensis and Discoaster drug-gii; LOs of Reticulofenestra bisecta, S. ciperoensis, and Cyclicargolithus abi-sectus; and occurrence of Triquetrorhabdulus carinatus allow theidentification of the subzones/intervals CP19–CN1a, CN1a, and CN1c–CN2.
The uppermost Eocene–lower Oligocene section (~5.5 m) can be as-signed to Zone CP16 based on the absence of Eocene discoasters (e.g.,Discoaster barbadiensis) and the presence of Isthmolithus recurvus andReticulofenestra umbilicus. Subzones CP16a–CP16c can be identified us-ing the first common occurrence of Clausicoccus subdistichus (SubzoneCP16b) and the LO of Coccolithus formosus (Subzone CP16c). The baseof Subzone CP16b is marked in the core by a prominent switch fromdark brown, in places barren, claystones to lighter-colored, grayish or-ange nannofossil ooze (see fig. F15 in Chapter 4, Shipboard ScientificParty, 2002). This switch to carbonate accumulation may reflect a sig-nificant post-Eocene/Oligocene boundary deepening of the carbonatecompensation depth (CCD) and is an event that is recognized else-where in the Pacific (van Andel, 1975; e.g., DSDP Sites 42, 70, 161, 162,and ODP Site 1217; Lyle, Wilson, Janecek, et al. 2002). This uppermostEocene–lower Oligocene section is bounded top and bottom by hiatusescomprising Zones CP17–CP18 (lower Oligocene) and Zones CP12–CP15(middle–upper Eocene), respectively.
The short (~0.75 m) upper Paleocene–lower Eocene section (see fig.F17 in Chapter 4, Shipboard Scientific Party, 2002) can be correlatedwith Zones CP8–CP11, based on the ranges of Discoaster multiradiatus,Discoaster diastypus, Rhomboaster bramlettei, Tribrachiatus orthostylus, andDiscoaster lodoensis and the decline and LO of Fasciculithus (Bralower etal., 1995; Aubry et al., 1996; Schmitz et al., 1997; see also Bralower, Pre-moli Silva, Malone, et al., 2002). The increase in Zygrhablithus bijugatus,recorded at this level elsewhere on Shatsky Rise, was not seen at Site1208 because this species was absent throughout. Its absence may bedue to greater dissolution at this deeper site.
A number of the samples in this interval yielded mixed assemblagesbut consideration of range continuity, abundance, and overall assem-blage character allowed construction of a relatively coherent stratig-raphy (Fig. F3). Nevertheless, the following zonal designations shouldbe viewed with some caution. Zone CP8 is identified using the FO of D.multiradiatus and Subzone CP9a the FOs of D. diastypus and R. bram-lettei. Subzone CP9b is identified using the LO of Tribrachiatus contortus,although this taxon was extremely rare; however, further support isprovided by the additional FOs of T. orthostylus (although problematicdue to mixing) and Sphenolithus radians. Zone CP10 is recognized using
P6. Discoasteraceae III, p. 31.
Discoaster bellus 1208A-29X-CC
D. triradiatus 1208A-28X-CC
D. quinqueramus 1208A-29X-CC
D. triradiatus 1208A-24X-CC
Discoaster berggrenii 1208A-25X-CC
D. quinqueramus 1208A-25X-CC
Discoaster berggrenii 1208A-26X-CC
D. quinqueramus 1208A-26X-CC
D. quinqueramus 1208A-26X-CC Discoaster berggrenii 1208A-27X-CC
Discoaster berggrenii 1208A-27X-CC
Discoaster hamatus 1208A-30X-CC Discoaster hamatus 1208A-29X-CC
2µm
D. tamalis 1208A-16H-CC D. tamalis 1208A-15H-CC D. tamalis 1208A-15H-CC
D. asymmetricus 1208A-18H-CC D. asymmetricus 1208A-18H-CC D. asymmetricus 1208A-21X-CC
D. ? blackstockiae 1208A-21X-CC
Discoaster berggrenii 1208A-27X-5
Discoaster hamatus 1208A-29X-CC
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23
24 25 26 27 28 29
30 31 32 33 34 35
36 37 38 39 40 41
2µm
D. asymmetricus 1208A-18H-CC
Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC
Discoaster hamatus 1208A-29X-CC
Discoaster berggrenii 1208A-27X-CC
P7. Discoasteraceae IV, Diatoms, p. 33.
D. prepentaradiatus 1208A-29X-CC
D. pentaradiatus 1208A-24X-CC
Catinaster coalitus 1208A-30X-CC
Catinaster calyculus 1208A-30X-CC
D. pentaradiatus 1208A-20H-CC
D. pentaradiatus 1208A-20H-CC
Catinaster coalitus 1208A-30X-2Catinaster coalitus 1208A-31X-2
Catinaster calyculus 1208A-30X-4
Actinoptychus sp. 1208A-23X-CC diatom 1208A-30X-CCDenticulopsis sp. 1208A-19H-CC Thalassiosira sp. 1208A-8H-CC Thalassiosira sp. 1208A-4H-CC Cyclotella sp. 1208A-1H-CC
Discoaster ?variabilis 1208A-28X-CC Discoaster variabilis 1208A-28X-CC Discoaster variabilis 1208A-30X-CC
1 2 3 4 5 6
18 19 20 21 22 23
30 31 32 33 34 35
2µm
Diatoms
36 37 38
24 25 26 27 28 29
12 13 14 15 16 17
7 8 9 10 11
P8. Noelaerhabdaceae, Coccolith-aceae, p. 35.
Cocco. formosus 1208A-35X-CC Cocco. pelagicus 1208A-35X-CC
Claussicoccus subdistichus 1208A-35X-CC
coccolith indet. 1208A-35X-CC
R. scrippsae (8.5µm) 1208A-35X-CC R. bisecta (10.6µm) 1208A-35X-CC
coccolith indet. 1208A-35X-CC
Br. serraculoides 1208A-35X-CC
Chi. barbatus side 1208A-35X-CCChiphrag. barbatus 1208A-35X-CC
Ret. umbilicus (18.5µm) 1208A-35X-CCChiasmolithus consuetus 1208A-36X-CC, 1.5
2µm
2µm
Neo. grandiculus 1208A-36X-2, 99
Ret. bisecta 1208A-36X-2, 40Cy. cf. C. floridanus 1208A-36X-2, 3Cycl. abisectus 1208A-36X-2, 3 Ret. umbilicus 1208A-36X-2, 40
Hay. situliformis 1208A-36X-2, 3
Campylosphaera sp. 1208A-36X-2, 99 Claus. subdistichus 1208A-36X-CC, 8
Calci. pacificanus 1208A-36X-2, 99
Ericsonia robusta 1208A-36X-CC, 5
Ret. bisecta (15.7µm) 1208A-35X-CC
Calci. pacificanus 1208A-36X-CC, 1.5?Hughesius sp. 1208A-36X-CC, 1.5
Ericsonia. cf. E. robusta 1208A-36X-CC, 12
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
2µm
Isthmo. recurvus 1208A-36X-2, 30
Calci. pacificanus 1208A-36X-2, 55
Calci. pacificanus 1208A-36X-2, 30
Tow. cf. T. callosus 1208A-36X-2, 90
Chias. consuetus 1208A-36X-CC, 2
Neo. grandiculus 1208A-36X-CC, 1.5
Markalius sp. 1208A-36X-2, 55
Noelarhabdaceae
Coccolithaceae
37 38 39 40
P9. Sphenolithaceae, p. 37.
Sph. predistentus 1208A-35X-CC
Sph. intercalaris 1208A-35X-CC Sph. moriformis 1208A-35X-CC
Sphenolithus villae 1208A-36X-CC, 1.5
Sph. ciperoensis 1208A-35X-5, 10
S. conspicuus 1208A-36X-2, 99
Sp. radians 1208A-36X-2, 99S. pseudoradians 1208A-36X-2, 3
2µm
Sp. cf. S. delphix 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-2, 99
Sphenolithus arthurii 1208A-36X-CC, 1.5
Spheno. arthurii 1208A-36X-CC, 1.5
Sp. cf. S. spiniger 1208A-36X-2, 99
2µm
Sp. cf. S. delphix 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-CC, 2
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
37 38 39 40 41
43 44 45 46 47 48
42
Sphenolithaceae
P10. Discoasteraceae V, p. 39.
D. diastypus 1208A-36X-CC, 1.5
D. barbadiensis 1208A-36X-CC, 1.5 D. binodosus 1208A-36X-CC, 1.5
Discoaster diastypus 1208A-36X-CC, 1.5 Discoaster tanii 1208A-35X-CC
Discoaster multiradiatus 1208A-36X-CC, 1.5
Disc. mohleri 1208A-36X-CC, 12Disc. mediosus 1208A-36X-CC, 4Disc. lenticularis 1208A-36X-CC, 4 Disc. lenticularis 1208A-36X-CC, 12
Disc. diastypus 1208A-36X-2, 99
Disc. mahmoudii 1208A-36X-CC, 4
Disc. araneus 1208A-36X-CC, 8
Disc. cf. D. araneus 1208A-36X-CC, 14Disc. cf. D. araneus 1208A-36X-CC, 12
D. cf. D. araneus 1208A-36X-CC, 12
Discoaster cf. D. araneus 1208A-36X-CC, 12 Discoaster cf. D. araneus 1208A-36X-CC, 4
Discoaster mediosus 1208A-36X-CC, 4Discoaster diastypus 1208A-36X-CC, 1.5
1
7 8 9 10 11 12
13 14 15 16 17 18
23
24 25 26 27
28 2931
2µm
Discoaster lodoensis 1208A-36X-2, 55
Disc. araneus 1208A-36X-CC, 2
19 20 21 22
2 3 4 5 6
Discoasteraceae
30 41
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 5
the FO of D. lodoensis, and the LO of T. orthostylus, at the top of this in-terval, indicates the presence of Zone CP11. The FO of Toweius crassus isa problematic datum and was not identified at this site. The Paleocene–Eocene section lies unconformably on Upper Cretaceous sediments.Cretaceous biostratigraphy is presented in detail in Lees and Bown(this volume).
SUMMARY
The expanded Neogene section comprises a continuous middle Mio-cene–Holocene section incorporating Zones CN4–CN15 and yieldingrich nannofossil and diatom assemblages. A number of subzone inter-vals were not recognized because of missing marker taxa. Sphenolithusand Helicosphaera exhibit particularly sporadic distribution patterns,but this is thought to be due to taxic exclusion or rarity rather than sig-nificant missing stratigraphy.
The lower Miocene–Paleocene section is a short (16 m), condensedsection incorporating at least three major hiatuses. Intriguingly, theunit appears to incorporate the Paleocene/Eocene boundary and theEocene/Oligocene boundary carbonate pulse.
The upper Oligocene–lower Miocene section (Zones CP19–CN2)(~1.1 m) is characterized by low-diversity assemblages dominated by D.deflandrei and C. floridanus.
The uppermost Eocene–lower Oligocene section (~5.5 m) includesthe C. subdistichus acme Subzone CP16a, which is marked in the core bya prominent switch from dark brown claystones to lighter-colored gray-ish orange nannofossil ooze. This switch to carbonate accumulation is asignificant post-Eocene/Oligocene event that is recognized elsewhere inthe Pacific.
The short (~0.75 m) upper Paleocene–lower Eocene section appearsto represent a short, continuous stratigraphic fragment that can be cor-related with Zones CP8–CP11, based on the ranges of D. multiradiatus,D. diastypus, R. bramlettei, T. orthostylus, and D. lodoensis and the declineand LO of Fasciculithus. The Paleocene/Eocene Thermal Maximum levellies within this interval.
ACKNOWLEDGMENTS
This research used samples provided by the Ocean Drilling Program(ODP). ODP is funded by the U.S. National Science Foundation (NSF)and participating countries under management of the Joint Oceano-graphic Institutions (JOI), Inc. Funding for ODP participation was pro-vided by the The Natural Environment Research Council (NERC), UK.The author would also like to acknowledge the contributions made bythe other ODP Leg 198 shipboard palaeontologists, namely, MarkLeckie, Maria Rose Petrizzo, Jason Eleson, Isabella Premoli Silva, TimBralower, and Kotaro Takeda, and the science party in general, whomade the leg so productive and enjoyable.
P11. Rhomboaster, Tribrachiatus, p. 41.
Trib. orthostylus 1208A-36X-CC, 1.5
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 5
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 5
R. bram.-spineus 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Trib. orthostylus 1208A-36X-CC, 4Trib. contortus 1208A-36X-CC, 5
Trib. digitalis 1208A-36X-CC, 8
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
2µm
Tribrac. contortus 1208A-36X-CC, 4 Tribrac. contortus 1208A-36X-CC, 235 36 3734 38 39
R. bramlettei side 1208A-36X-CC, 4
25 26 27 28
29 30 31 32 33
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4
Rhomb. cuspis 1208A-36X-CC, 5
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4 Rhomb. bramlettei 1208A-36X-CC, 4
Trib. contortus 1208A-36X-CC, 5
Trib. digitalis 1208A-36X-CC, 8
P12. Fasciculithaceae, p. 43.
calcisphere 1208A-36X-CC, 1.5 calcisphere 1208A-36X-2, 99
Fasc. alanii 1208A-36X-CC, 12 Fasc. aubertae 1208A-36X-CC, 12 Fascic. bobii 1208A-36X-CC, 14
Fasc. bobii 1208A-36X-CC, 12
Fasc. bobii 1208A-36X-CC, 12
F. tympaniformis 1208A-36X-CC, 8 F. tympaniformis 1208A-36X-CC, 12 Fasc. tonii 1208A-36X-CC, 12
Fascic. fenestrellatus 1208A-36X-CC, 12
1 2 3 4 5 6
7 8 9 10 11 12
2µm
Fascic. sidereus 1208A-36X-CC, 8
Fascic. fenestrellatus 1208A-36X-CC, 8
Fascic. sp. 1 1208A-36X-CC, 8
Fascic. tonii 1208A-36X-CC, 8Fasc. tonii 1208A-36X-CC, 12
Fasc. tonii 1208A-36X-CC, 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29
30 31 32 33
Fasciculithaceae
Fasc. alanii 1208A-36X-CC, 12 Fascic. bobii 1208A-36X-CC, 14
Fasc. tonii 1208A-36X-CC, 12
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 6
REFERENCES
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Bown, P.R. (Ed.), 1998. Calcareous Nannofossil Biostratigraphy: Dordrecht, The Nether-lands (Kluwer Academic Publ.).
Bown, P.R., 2005. Palaeogene calcareous nannofossils from the Kilwa and Lindi areasof coastal Tanzania (Tanzania Drilling Project sites 2003–4). J. Nannoplankton Res.,27:21–95.
Bown, P.R., and Young, J.R., 1998. Techniques. In Bown, P.R. (Ed.), Calcareous Nanno-fossil Biostratigraphy: Dordrecht, The Netherlands (Kluwer Academic Publ.), 16–28.
Bralower, T.J., 1987. Valanginian to Aptian calcareous nannofossil stratigraphy andcorrelation with the upper M-sequence magnetic anomalies. Mar. Micropaleontol.,11:293–310.
Bralower, T.J., Premoli Silva, I., Malone, M.J., et al., 2002. Proc. ODP, Init. Repts., 198[CD-ROM]. Available from: Ocean Drilling Program, Texas A&M University, Col-lege Station TX 77845-9547, USA.
Bralower, T.J., Sliter, W.V., Arthur, M.A., Leckie, R.M., Allard, D.J., and Schlanger, S.O.,1993. Dysoxic/anoxic episodes in the Aptian–Albian (Early Cretaceous). In Pringle,M.S., Sager, W.W., Sliter, W.V., and Stein, S. (Eds.), The Mesozoic Pacific: Geology, Tec-tonics, and Volcanism. Geophys. Monogr., 77:5–37.
Bralower, T.J., Zachos, J.C., Thomas, E., Parrow, M., Paull, C.K., Kelly, D.C., PremoliSilva, I., Sliter, W.V., and Lohmann, K.C., 1995. Late Paleocene to Eocene pale-oceanography of the equatorial Pacific Ocean: stable isotopes recorded at OceanDrilling Program Site 865, Allison Guyot. Paleoceanography, 10:841–865.
Burnett, J.A., with contributions from Gallagher, L.T., and Hampton, M.J., 1998.Upper Cretaceous. In Bown, P.R. (Ed.), Calcareous Nannofossil Biostratigraphy: Dor-drecht, The Netherlands (Kluwer Academic Publ.), 132–199.
Klaus, A., and Sager, W.W., 2002. Data report: High-resolution site survey seismicreflection data for ODP Leg 198 drilling on Shatsky Rise, northwest Pacific. In Bral-ower, T.J., Premoli Silva, I., Malone, M.J., et al., Proc. ODP, Init. Repts., 198 [Online].Available from World Wide Web: http://www-odp.tamu.edu/publications/198_IR/chap_11/chap_11.htm.
Lyle, M., Wilson, P.A., Janecek, T.R., et al., 2002. Proc. ODP, Init. Repts., 199 [CD-ROM].Available from: Ocean Drilling Program, Texas A&M University, College Station TX77845-9547, USA.
Okada, H., and Bukry, D., 1980. Supplementary modification and introduction ofcode numbers to the low-latitude coccolith biostratigraphic zonation (Bukry, 1973;1975). Mar. Micropaleontol., 5:321–325.
Perch-Nielsen, K., 1985a. Cenozoic calcareous nannofossils. In Bolli, H.M., Saunders,J.B., and Perch-Nielsen, K. (Eds.), Plankton Stratigraphy: Cambridge (CambridgeUniv. Press), 427–554.
Perch-Nielsen, K., 1985b. Mesozoic calcareous nannofossils. In Bolli, H.M., Saunders,J.B., and Perch-Nielsen, K. (Eds.), Plankton Stratigraphy: Cambridge (CambridgeUniv. Press), 329–426.
Robinson, S.A., Williams, T., and Bown, P.R., 2004. Fluctuations in biosiliceous pro-duction and the generation of Early Cretaceous oceanic anoxic events in thePacific Ocean (Shatsky Rise, ODP Leg 198). Paleoceanography, 19(PA4024):10.1029/2004PA001010.
Roth, P.H., 1978. Cretaceous nannoplankton biostratigraphy and oceanography ofthe northwestern Atlantic Ocean. In Benson, W.E., Sheridan, R.E., et al., Init. Repts.DSDP, 44: Washington (U.S. Govt. Printing Office), 731–759.
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 7
Roth, P.H., 1983. Jurassic and Lower Cretaceous calcareous nannofossils in the west-ern North Atlantic (Site 534): biostratigraphy, preservation, and some observationson biogeography and paleoceanography. In Sheridan, R.E., Gradstein, F.M., et al.,Init. Repts. DSDP, 76: Washington (U.S. Govt. Printing Office), 587–621.
Schmitz, B., Asaro, F., Molina, E., Monechi, S., von Salis, K., and Speuijer, R.P., 1997.High-resolution iridium δ13C, δ18O, foraminifera and nannofossil profiles acrossthe latest Paleocene benthic extinction event at Zumaya, Spain. Palaeogeogr., Palae-oclimatol., Palaeoecol., 133:49–68.
van Andel, T.H., 1975. Mesozoic/Cenozoic calcite compensation depth and the globaldistribution of calcareous sediments. Earth Planet. Sci. Lett., 26:187–194.
Young, J.R., 1998. Neogene. In Bown, P.R. (Ed.), Calcareous Nannofossil Biostrati-graphy: Dordrecht, The Netherlands (Kluwer Academic Publ.), 225–265.
Young, J.R., Bergen, J.A., Bown, P.R., Burnett, J.A., Fiorentino, A., Jordan, R.W.,Kleijne, A., van Niel, B.E., Ton Romein, A.J., von Salis, K., 1997. Guidelines for coc-colith and calcareous nannofossil terminology. Paleontology, 40:875–912.
Young, J.R., and Bown, P.R., 1997. Cenozoic calcareous nannoplankton classification.J. Nannoplankton Res., 19:36–47.
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 8
APPENDIX A
Systematic Taxonomy
The systematic paleontology section includes brief taxonomic noteson a number of key taxa and the description of two new species, Sphe-nolithus arthurii and Fasciculithus fenestrellatus. The taxonomy followsthe classification and organization of Young and Bown (1997) andYoung (1998). Only bibliographic references not included in Perch-Nielsen (1985a, 1985b) and Bown (1998) are included in the referencelist. A full taxonomic list of species cited in this paper follows in “Ap-pendix B,” p. 10. Descriptive terminology follows the guidelines ofYoung et al. (1997), and the following abbreviations are used in taxo-nomic descriptions: LM = light microscope, XPL = cross polarized light,PC = phase-contrast illumination. The taxa are illustrated in Plates P1–P12.
Neocrepidolithus grandiculus Bown, 2005Pl. P8, figs. 4, 5
Description: Large murolith coccolith with a broad rim, unicyclic in XPL,and a narrow, vacant central area. The central area width is variable, usuallyaround the same width as the rim, but may be narrower or closed. Similar inmorphology to the Jurassic species Crepidolithus crassus and distinguished fromother Paleogene Neocrepidolithus species by its larger size, open central area, andsimple unicyclic rim image.
Dimensions: length = 9.0–13.5 µm; width = 6.5–10.0 µm.Occurrence: lower Eocene (Zone CP9) at Site 1208; Zone CP8–Subzone
CP9b, Tanzania (Bown, 2005).
Discoaster cf. D. araneus Bukry, 1971Pl. P10, figs. 2, 19, 20, 24–27
Remarks: Large discoasters with 6–8 rays, free for around half their length,and curving, although the degree of curvature is variable. Arrangement of raysusually shows asymmetry. The central area is broad and appears to be flat andunadorned.
Differentiation: Does not possess a central area stem like D. araneus and dif-ferentiated from D. lodoensis by asymmetry, variable degree of ray curvature,and shorter free ray length.
Occurrence: upper Paleocene–lower Eocene (Zone CP8–Subzone CP9b) atSite 1208.
Sphenolithus villae Bown, 2005Pl. P9, figs. 23–39
Description: Large, robust sphenolith with tall proximal cycle (lower quad-rants in XPL; see Young et al., 1997) and tall, tapering, monocrystalline apicalspine. The base is taller than it is wide and appears as four quadrants separatedby a clear extinction cross at 0°; the lower quadrants are as much as twice as tallas the upper quadrants. At 45° the base is crossed by diagonal extinction lines,and lateral cycles are visible, showing varying birefringence. The spine is tall(usually equivalent to the height of the base, but may be shorter) and insertedinto the upper quadrants in a V-shape. The spine appears to be monocrystallineand is dark at 0° and brightest at 45°. Comparable in general morphology to theMiocene Sphenolithus belemnos; however, S. villae is larger and more robustlyconstructed, with blockier spine and base.
Dimensions: height = 9.0–12.0 µm; width = 3.0–5.0 µm.Occurrence: lower Eocene (Zone CP9) at Site 1208; Subzones CP8b–CP9b,
Tanzania (Bown, 2005)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 9
Sphenolithus arthurii sp. nov.Pl. P9, figs. 1–7
Derivation of name: Named for Mike Arthur, paleoceanographer and ODP198 shipboard scientist.
Diagnosis: Large, robust sphenolith with squat, square base and short,sharply tapering spine. The base is coarsely constructed, square-shaped, andcrossed by an extinction cross at 0°; the lower and upper quadrants are nearequidimensional. At 45° the base is crossed by diagonal extinction lines. Thespine is short (equal to or shorter than the base) and tapers sharply to a point.The spine is compound and may be divided by a median extinction line at 0°,where it is darkest but still visible. The spine is brightest at 45°.
Differentiation: Comparable in general morphology to Sphenolithus radians;however, S. arthurii is larger and more coarsely constructed, with blockier spineand base.
Dimensions: height = 7.0–11.0 µm; width = 5.0–8.0 µm.Holotype: Pl. P9, fig. 3 (fig. 4 is the same specimen).Paratype: Pl. P9, fig. 5 (fig. 6 is the same specimen); Pl. P9, fig. 2 (fig. 1 is the
same specimen).Type locality: Leg 198, Site 1208, Shatsky Rise, northwest Pacific Ocean.Type level: lower Eocene, Sample 198-1208A-36X-CC, 1.5 cm (Subzone
CP9b).Occurrence: lower Eocene (Subzone CP9b) at Site 1208.
Fasciculithus fenestrellatus sp. nov.Pl. P12, figs. 19–24
Derivation of name: From fenestra, ella, and atus, meaning “with little win-dows,” and referring to the distinct ornamentation of this fasciculith.
Diagnosis: Large, tall fasciculith that tapers toward its base and is orna-mented with large, rectangular fenestrae delineated by distinct longitudinal andtransverse ridges. The fasciculith is taller than it is wide. The LM image is notthe typical two blocks seen in smaller fasciculiths, the median extinction linebeing indistinct.
Dimensions: height = 12.3 µm; width = 9.8 µm.Holotype: Pl. P12, fig. 21 (figs. 21–24 are the same specimen).Paratype: Pl. P12, fig. 19 (fig. 20 is the same specimen).Type locality: Leg 198, Site 1208, Shatsky Rise, northwest Pacific Ocean.Type level: upper Paleocene, Sample 198-1208A-36X-CC, 12 cm (Zone CP8).Occurrence: upper Paleocene (Zone CP8) at Site 1208.
Fasciculithus sp. 1Pl. P12, figs. 25–27
Description: Large fasciculith that tapers slightly toward its base and is orna-mented with thick, rounded, protruding ridges. This fasciculith is broader thanit is tall and possesses a relatively wide central opening. The LM image is notthe typical two blocks seen in smaller fasciculiths.
Dimensions: height = 11.0 µm; width = 14.4 µm.Occurrence: upper Paleocene (Zone CP8) at Site 1208.
Rhomboaster cuspis Bramlette and Sullivan, 1961Pl. P11, figs. 1–12
Remarks: Broadly cubic-rhombic morphology with variable-length ray ex-tensions from the corners. Cubic shape prevents the nannolith lying on onecorner, as seen in Rhomboaster bramlettei.
Rhomboaster bramlettei (Bronnimann and Stradner, 1960) Bybell and Self-Trail, 1995
Pl. P11, figs. 13–27Remarks: LM image shows two offset, superimposed, triradiate structures;
rarely observed in side view (Pl. P11, figs. 22, 23).
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 10
APPENDIX B
Taxonomic List
A full list of all taxa cited in the text, figures, and range charts isgiven below. Most bibliographic references can be found in Perch-Nielsen (1985a, 1985b) and Bown (1998).
Amaurolithus amplificus (Bukry and Percival, 1971) Gartner and Bukry, 1975Amaurolithus bizarrus (Bukry, 1973) Gartner and Bukry, 1975Amaurolithus delicatus Gartner and Bukry, 1975Amaurolithus primus (Bukry and Percival, 1971) Gartner and Bukry, 1975Amaurolithus tricorniculatus (Gartner, 1967) Gartner and Bukry, 1975Bramletteius serraculoides Gartner, 1969Broinsonia parca (Stradner, 1963) Bukry, 1969 ssp. constricta Hattner et al., 1980Broinsonia parca (Stradner, 1963) Bukry, 1969 ssp. parcaCalcidiscus leptoporus (Murray and Blackman, 1898) Loeblich and Tappan, 1978Calcidiscus macintyrei (Bukry and Bramlette, 1969) Loeblich and Tappan, 1978Calcidiscus pacificanus (Bukry, 1971) Varol, 1989Calcidiscus premacintyrei Theodoridis, 1984Calcidiscus tropicus Kamptner, 1956 sensu Gartner, 1992Calciosolenia Gran, 1912Calciosolenia murrayi Gran, 1912Catinaster calyculus Martini and Bramlette, 1963Catinaster coalitus Martini and Bramlette, 1963Catinaster coalitus Martini and Bramlette, 1963 ssp. extensus Peleo-Alampay,
Bukry, Liu, and Young, 1998Ceratolithoides aculeus (Stradner, 1961) Prins and Sissingh in Sissingh, 1977Ceratolithus cristatus Kamptner, 1950Ceratolithus rugosus Bukry and Bramlette, 1968Ceratolithus telesmus Norris, 1965Chiasmolithus Hay, Mohler, and Wade, 1966Chiasmolithus consuetus (Bramlette and Sullivan, 1961) Hay and Mohler, 1967Chiasmolithus eograndis Perch-Nielsen, 1971Chiasmolithus grandis (Bramlette and Riedel, 1964) Radomski, 1968Chiasmolithus nitidus Perch-Nielsen, 1971Chiasmolithus solitus (Bramlette and Sullivan, 1961) Locker, 1968Chiphragmalithus barbatus Perch-Nielsen, 1967Clausicoccus subdistichus (Roth and Hay in Hay et al., 1967) Prins, 1979Coccolithus eopelagicus (Bramlette and Riedel, 1954) Bramlette and Sullivan,
1961Coccolithus formosus (Kamptner, 1963) Wise, 1973Coccolithus miopelagicus Bukry, 1971Coccolithus pelagicus (Wallich, 1871) Schiller, 1930Coronocyclus nitescens (Kamptner, 1963) Bramlette and Wilcoxon, 1967Crepidolithus crassus (Deflandre in Deflandre and Fert, 1954) Noël, 1965Cretarhabdus Bramlette and Martini, 1964Cruciplacolithus edwardsii Romein, 1979Cryptococcolithus mediaperforatus (Varol, 1991) de Kaenel and Villa, 1996Cyclicargolithus abisectus (Müller, 1970) Wise, 1973Cyclicargolithus floridanus (Roth and Hay in Hay et al., 1967) Bukry, 1971Discoaster anartios Bybell and Self-Trail, 1995Discoaster araneus Bukry, 1971Discoaster asymmetricus Gartner, 1969Discoaster barbadiensis Tan, 1927Discoaster bellus Bukry and Percival, 1971Discoaster bergenii Knuttel et al., 1989Discoaster berggrenii Bukry, 1971bDiscoaster binodosus Martini, 1958Discoaster blackstockiae Bukry, 1973
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 11
Discoaster bollii Martini and Bramlette, 1963Discoaster braarudii Bukry, 1971Discoaster brouweri Tan, 1927, emend. Bramlette and Riedel, 1954Discoaster calcaris Gartner, 1967Discoaster challengeri Bramlette and Riedel, 1954Discoaster deflandrei Bramlette and Riedel, 1954Discoaster diastypus Bramlette and Sullivan, 1961Discoaster druggii Bramlette and Wilcoxon, 1967Discoaster elegans Bramlette and Sullivan, 1961Discoaster exilis Martini and Bramlette, 1963Discoaster falcatus Bramlette and Sullivan, 1961Discoaster hamatus Martini and Bramlette, 1963Discoaster kuepperi Stradner, 1959Discoaster kugleri Martini and Bramlette, 1963Discoaster lenticularis Bramlette and Sullivan, 1961Discoaster lodoensis Bramlette and Riedel, 1954Discoaster loeblichii Bukry, 1971Discoaster mahmoudii Perch-Nielsen, 1981Discoaster mediosus Bramlette and Sullivan, 1961Discoaster megastypus (Bramlette and Sullivan, 1961) Perch-Nielsen, 1985Discoaster mohleri Bukry and Percival, 1971Discoaster musicus Stradner, 1959Discoaster nobilis Martini, 1961Discoaster neorectus Bukry, 1971Discoaster pentaradiatus Tan, 1927Discoaster petaliformis Moshkovitz and Ehrlich, 1980Discoaster prepentaradiatus Bukry and Percival, 1971Discoaster quinqueramus Gartner, 1969Discoaster salisburgensis Stradner, 1961Discoaster surculus Martini and Bramlette, 1963Discoaster tamalis Kamptner, 1967Discoaster tanii Bramlette and Riedel, 1954Discoaster tanii Bramlette and Riedel, 1954, ssp. nodifer Bramlette and Riedel,
1954Discoaster tanii Bramlette and Riedel, 1954, ssp. ornatus Bramlette and Wil-
coxon, 1967Discoaster triradiatus Tan, 1927Discoaster variabilis Martini and Bramlette, 1963Eiffellithus eximius (Stover, 1966) Perch-Nielsen, 1968Ellipsolithus macellus (Bramlette and Sullivan, 1961) Sullivan, 1964Emiliania huxleyi (Lohmann, 1902) Hay and Mohler in Hay et al., 1967Ericsonia robusta (Bramlette and Sullivan, 1961) Perch-Nielsen, 1977Fasciculithus alanii Perch-Nielsen, 1971Fasciculithus aubertae Haq and Aubry, 1981Fasciculithus bobii Perch-Nielsen, 1971Fasciculithus clinatus Bukry, 1971Fasciculithus fenestrellatus sp. nov.Fasciculithus schaubii Hay and Mohler in Hay et al., 1967Fasciculithus sidereus Bybell and Self-Trail, 1995Fasciculithus tonii Perch-Nielsen, 1971Fasciculithus tympaniformis Hay and Mohler in Hay et al., 1967Florisphaera profunda Okada and Honjo, 1973Gephyrocapsa Kamptner, 1943Gephyrocapsa aperta Kamptner, 1963Gephyrocapsa caribbeanica Boudreaux and Hay, 1967Gephyrocapsa oceanica Kamptner, 1943Gephyrocapsa omega Bukry, 1973Gephyrocapsa parallela Hay and Beaudry, 1973Girgisia gammation (Bramlette and Sullivan, 1961) Varol, 1989Hayella situliformis Gartner, 1969
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 12
Hayesites irregularis (Thierstein in Roth and Thierstein, 1972) Applegate et al. inCovington and Wise, 1987
Helicosphaera ampliaperta Bramlette and Wilcoxon, 1967Helicosphaera carteri (Wallich, 1877) Kamptner, 1954Helicosphaera granulata (Bukry and Percival, 1971) Jafar and Martini, 1975Helicosphaera inversa (Gartner, 1980) Theodoridis, 1984Helicosphaera sellii (Bukry and Bramlette, 1969) Jafar and Martini, 1975Helicosphaera wallichii (Lohmann, 1902) Boudreaux and Hay, 1969Hughesius gizoensis Varol, 1989Isthmolithus recurvus Deflandre in Deflandre and Fert, 1954Markalius inversus (Deflandre in Deflandre and Fert, 1954) Bramlette and Mar-
tini, 1964Micula murus (Martini, 1961) Bukry, 1973Minylitha convallis Bukry, 1973Neocrepidolithus Romein, 1979Neocrepidolithus grandiculus Bown, 2005Neosphaera coccolithomorpha Lecal-Schlauder, 1950Pontosphaera discopora Schiller, 1925Pontosphaera japonica (Takayama, 1967) Nishida, 1971Pontosphaera multipora (Kamptner, 1948) Roth, 1970Pseudoemiliania lacunosa (Kamptner, 1963) Gartner, 1969Pseudoemiliania ovata (Bukry, 1973) Young, 1998Reticulofenestra asanoi Sato and Takayama, 1992Reticulofenestra dictyoda (Deflandre in Deflandre and Fert, 1954) Stradner in
Stradner and Edwards, 1968Reticulofenestra haqii Backman, 1978Reticulofenestra lockeri Müller, 1970Reticulofenestra minuta Roth, 1970Reticulofenestra minutula (Gartner, 1967) Haq and Berggren, 1978Reticulofenestra pseudoumbilicus (Gartner, 1967) Gartner, 1969Reticulofenestra rotaria Theodoridis, 1984Reticulofenestra scrippsae (Bukry and Percival, 1971) Roth, 197Reticulofenestra stavensis (Levin and Joerger, 1967) Varol, 1989Reticulofenestra umbilicus (Levin, 1965) Martini and Ritzkowski, 1968Rhabdosphaera clavigera Murray and Blackman, 1898Rhomboaster cuspis Bramlette and Sullivan, 1961Rhomboaster bramlettei (Bronnimann and Stradner, 1960) Bybell and Self-Trail,
1995Rhomboaster spineus (Shafik and Stradner, 1961) Perch-Nielsen, 1984Sphenolithus abies Deflandre in Deflandre and Fert, 1954Sphenolithus arthurii sp. nov.Sphenolithus belemnos Bramlette and Wilcoxon, 1967Sphenolithus calyculus Bukry, 1985Sphenolithus capricornutus Bukry and Percival, 1971Sphenolithus ciperoensis Bramlette and Wilcoxon, 1967Sphenolithus conspicuus Martini, 1976Sphenolithus delphix Bukry, 1973Sphenolithus dissimilis Bukry and Percival, 1971Sphenolithus editus Perch-Nielsen in Perch-Nielsen et al., 1978Sphenolithus heteromorphus Deflandre, 1953Sphenolithus intercalaris Martini, 1976Sphenolithus moriformis (Brönnimann and Stradner, 1960) Bramlette and Wil-
coxon, 1967Sphenolithus predistentus Bramlette and Wilcoxon, 1967Sphenolithus radians Deflandre in Grassé, 1952Sphenolithus spiniger Bukry, 1971Sphenolithus pseudoradians Bramlette and Wilcoxon, 1967Sphenolithus villae Bown, 2005Syracosphaera pulchra Lohmann, 1902Tetralithoides symeonidesii Theodoridis, 1984Toweius Hay and Mohler, 1967
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 13
Toweius callosus Perch-Nielsen, 1971Toweius pertusus (Sullivan, 1965) Romein, 1979Tranolithus orionatus (Reinhardt, 1966) Reinhardt, 1966Tribrachiatus contortus (Stradner, 1958) Bukry, 1972Tribrachiatus digitalis Aubry, 1995Tribrachiatus orthostylus Shamrai, 1963Triquetrorhabdulus carinatus Martini, 1965Triquetrorhabdulus rugosus Bramlette and Wilcoxon, 1967Umbellosphaera tenuis (Kamptner, 1937) Paasche in Markali and Paasche, 1955Umbilicosphaera hulburtiana Gaarder, 1970Umbilicosphaera jafari Müller, 1974Umbilicosphaera rotula (Kamptner, 1956) Varol, 1982Umbilicosphaera sibogae (Weber-van Bosse, 1901) Gaarder, 1970Uniplanarius trifidus (Stradner in Stradner and Papp, 1961) Hattner and Wise,
1980
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 14
Figure F1. Bathymetric map of Shatsky Rise and the location of Shatsky Rise in the Pacific Ocean (inset).The main map indicates the location of ODP and DSDP sites on Shatsky Rise, whereas the inset shows thelocation of Shatsky Rise in the Pacific Ocean relative to other Cretaceous volcanic features (modified fromBralower, Premoli Silva, Malone, et al., 2002; Klaus and Sager, 2002; Robinson et al., 2004).
155°E 160°
30°
35°
165° 170°
40°N
0 500
km
305 and1211
306 and1214
1212
SliterBasin
Helios Basin
1213
1209
1210
50
1207
1208
ShatskyRise Magellan
Manihiki
Ontong Java
Mid-PacificMts
Hess
Southern High
Central High
Northern High
Ojin Rise seamounts
Papa
nin
Rid
ge
3000 mbsl4000 mbsl5000 mbsl
Pacific Ocean
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 15
Figure F2. Age-depth plot of calcareous nannofossil datums (red squares) from Site 1208. Cretaceous datafrom this work and Lees and Bown (this volume). FO = first occurrence, LO = last occurrence.
FO E. huxleyi
LO G. omega
FO G. caribbeanica
FO D. brouweri
LO D. tamalis
LO R. pseudoumbilicus
FO C. cristatus
LO D. quinqueramus
FO D. berggrenii
FO Amaurolithus
LO D. hamatus
FO C. coalitus
LO C. premacintyrei
LO H. irregularis
FO B. parca parcaFO B. parca constricta
LO E. eximius
LO U. trif.
FO D. multiradiatus
FO R. bram.FO D. lodo.
S. hetero.
FO D. druggi
0 10
20
80
120
140
160
180
200
220
240
260
280
300
Age (Ma)
Dep
th (
mbs
f)
Neogene Paleogene Cretaceous
20 40 50 60 70 80 90 10030 110
FO R. stavensis
R. umbilicus
acme C. subdistichus
320
340
360
380
400
100
60
40
42.0 m/m.y.
35.1 m/m.y.
25.1 m/m.y.
10.9 m/m.y.
0.6m/m.y.
6.0 m/m.y.
0
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 16
Figure F3. Age-depth plot of calcareous nannofossil datums (red squares) for the Neogene of Site 1208.Magnetostratigraphic datums from Evans et al. (this volume) (blue circles). FO = first occurrence, LO = lastoccurrence.
8 10 1812 2014 16
FO E. huxleyi
LO P. lacunosa
LO G. omega
FO G. caribbeanica
FO D. brouweri
LO D. pentaradiatusLO D. surculus
LO D. tamalis
FO D. tamalis, D. asymmetricus
LO Amaurolithus
FO C. cristatus
LO D. quinqueramus
FO D. berggrenii
FO Amaurolithus
FO D. hamatusFO C. coalitusLO C. miopelagicus
LO C. premacintyrei LO C. floridanus
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
Age (Ma)
Pleis. Pliocene late Miocene middle Miocene
LO Spheno.
LO R. ps.
22
FO D. druggii
FO S. hetero.LO S. heteromorphus
FO R. pseudo. >7 µm
FO C. calyculusLO D. hamatus
24
320
340
Dep
th (
mbs
f)
early Miocene Ol.
52.4 m/m.y.
35.1 m/m.y.
25.1 m/m.y.
10.9 m/m.y.
0.6 m/m.y.
4.5 m/m.y.
LOR. stavensis
0 2 4 60
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 17
Figure F4. Age-depth plot of calcareous nannofossil datums (red squares) for the Paleogene of Site 1208.Cretaceous data from this work and Lees and Bown (this volume). FO = first occurrence, LO = last occur-rence.
LO acme C. subdistichusLO B. parca constricta
LO U. trif.
FO D. multirad.FO R. bramlettei
FO D. lodoensis
LO S. heteromorphus
LO R. stavensis
FO D. druggii
FO S. heteromorphus
LO S. ciperoensis
LO R. umbilicus
FO acme C. subdistichus
FO I. recurvus
LO R. stavensis
FO R. umbilicus
LO E. eximius
0 10
316
318
320
322
324
326
328
330
Age (Ma)
Dep
th (
mbs
f)
P.Plio. Miocene Eocene
20 30 40 50 60 70 80314
Oligocene Paleog. Cretaceous
6.0 m/m.y.
5.6 m/m.y.
0.6 m/m.y.
0.1m/m.y.
LO C. abisectus
LO C. formosus
LO T. orthostylus
LO D. barbadiensis
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 18
Table T1. Calcareous nannofossil stratigraphic range chart, Site 1208. (This table is available in an over-sized format.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 19
Table T2. Paleogene–lower Miocene stratigraphic range chart, Site 1208. (This table is available in an over-sized format.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 20
Table T3. Calcareous nannofossil datums, ages and depths.
Notes: Age data from Shipboard Scientific Party (2002; Chapter 2, figs. F4, F5; and refer-ences therein) and Young (1998). Cretaceous data from this work and Lees and Bown(this volume).
DatumDepth (mbsf)
Age(Ma) Age data source
FO Emiliania huxleyi 14.24 0.26 Shipboard Scientific Party, 2002aLO P. lacunosa 30.30 0.46 Shipboard Scientific Party, 2002aFO G. omega 43.11 0.95 Shipboard Scientific Party, 2002aFO G. caribbeanica 87.90 1.73 Shipboard Scientific Party, 2002aLO D. brouweri 100.16 1.95 Shipboard Scientific Party, 2002aLO D. pentaradiatus 116.40 2.52 Shipboard Scientific Party, 2002aLO D. surculus 119.08 2.63 Shipboard Scientific Party, 2002aLO D. tamalis 128.70 2.78 Shipboard Scientific Party, 2002aLO Large Reticulofenestra 163.90 3.82 Shipboard Scientific Party, 2002aFO D. tamalis 166.66 4.20 Young, 1998LO Sphenolithus 166.66 3.65 Shipboard Scientific Party, 2002aLO Amaurolithus 168.88 4.56 Shipboard Scientific Party, 2002aFO D. asymmetricus 168.88 4.20 Young, 1998FO C. cristatus 187.90 5.07 Shipboard Scientific Party, 2002aLO D. quinqueramus 207.00 5.54 Shipboard Scientific Party, 2002aFO Amaurolithus 235.52 7.39 Shipboard Scientific Party, 2002aFO D. quinqueramus 250.80 8.20 Shipboard Scientific Party, 2002aFO D. berggrenii 250.80 8.20 Shipboard Scientific Party, 2002aFO D. hamatus 265.94 9.63 Shipboard Scientific Party, 2002aFO C. calyculus 270.10 10.10 Young, 1998FO D. hamatus 274.20 10.48 Shipboard Scientific Party, 2002aFO C. coalitus 279.70 10.79 Shipboard Scientific Party, 2002aLO C. miopelagicus 285.06 10.90 Young, 1998LO C. premacintyrei 295.41 12.30 Young, 1998LO C. floridanus 295.41 13.19 Shipboard Scientific Party, 2002aFO R. pseudoumbilicus (>7 µm) 303.10 13.70 Young, 1998LO S. heteromorphus 314.17 13.52 Shipboard Scientific Party, 2002aFO S. heteromorphus 319.05 18.20 Shipboard Scientific Party, 2002aFO D. druggii 319.92 23.20 Shipboard Scientific Party, 2002aLO C. abisectus 320.30 23.50 Young, 1998LO R. bisecta 320.79 23.90 Shipboard Scientific Party, 2002aLO S. ciperoensis 320.79 25.50 Shipboard Scientific Party, 2002aLO R. umbilicus 321.30 32.30 Shipboard Scientific Party, 2002aLO C. formosus 321.75 32.80 Shipboard Scientific Party, 2002aTop acme C. subdistichus 325.00 32.80 Young, 1998Base acme C. subdistichus 326.30 33.30 Shipboard Scientific Party, 2002aFO I. recurvus 326.80 36.00 Shipboard Scientific Party, 2002aFO R. stavensis 326.80 38.00 Shipboard Scientific Party, 2002aFO R. umbilicus 326.80 43.70 Shipboard Scientific Party, 2002aLO D. barbadiensis 326.82 34.30 Shipboard Scientific Party, 2002aLO T. orthostylus 326.83 50.60 Shipboard Scientific Party, 2002aFO D. lodoensis 327.20 52.80 Shipboard Scientific Party, 2002aFO Rhomboaster 327.48 55.00 Shipboard Scientific Party, 2002aFO D. multiradiatus 327.58 56.20 Shipboard Scientific Party, 2002aLO U. trifidus 327.68 71.30 Shipboard Scientific Party, 2002aLO B. parca constricta 327.68 74.60 Shipboard Scientific Party, 2002aLO E. eximius 327.70 75.30 Shipboard Scientific Party, 2002aFO B. parca constricta 371.53 82.50 Shipboard Scientific Party, 2002aFO B. parca parca 376.14 83.40 Shipboard Scientific Party, 2002aLO H. irregularis 382.90 101.00 Shipboard Scientific Party, 2002a
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 21
Plate P1. Helicosphaeraceae, Pontosphaeraceae, Noelaerhabdaceae, Reticulofenestra. Taxonomic organiza-tion and concepts are generally comparable to those of Young and Bown (1997) and Young (1998). Imageswith black background are cross-polarized light images; those with light backgrounds are phase-contrastimages. 1. Helicosphaera carteri (Sample 198-1208A-8H-CC). 2. Helicosphaera granulata (Section 198-1208A-34X-5). 3, 4. Helicosphaera inversa (Sample 198-1208A-3H-CC). 5, 6. Helicosphaera sellii (Section 198-1208A-13H-5). 7, 8. Pontosphaera discopora; (7) Sample 198-1208A-9H-CC, (8) Section 198-1208A-2H-5.9. Pontosphaera multipora (Sample 198-1208A-18H-CC). 10. Syracosphaera pulchra (Sample 198-1208A-8H-CC). 11. Rhabdosphaera clavigera (Section 198-1208A-1H-4). 12. Calciosolenia brasiliensis (Section 198-1208A-1H-4). 13. Cyclicargolithus ?abisectus (11.4 µm) (Sample 198-1208A-32X-CC). 14–17. Cyclicargolithusfloridanus; (14) 10.1 µm (Sample 198-1208A-27X-CC), (15) 9.3 µm (Sample 198-1208A-32X-CC), (16) 7.5µm (Sample 198-1208A-32X-CC), (17) Sample 198-1208A-35X-CC. 18. Reticulofenestra bisecta (10.6 µm)(Sample 198-1208A-35X-CC). 19. Small reticulofenestrids (~1.7 µm) (Sample 198-1208A-18H-CC).20. Reticulofenestra minuta (2.8 µm) (Sample 198-1208A-5H-CC). 21–25. Reticulofenestra haqii; (21) 3.1 µm(Sample 198-1208A-18H-CC), (22) 4 µm (Sample 198-1208A-27X-CC), (23) 4.3 µm (Sample 198-1208A-16H-CC), (24) 4.1 µm (Sample 198-1208A-14H-CC), (25) 4.7 µm (Sample 198-1208A-9H-CC). 26, 27. Retic-ulofenestra haqii-asanoi; (26) 5.4 µm (Core 198-1208A-7H), (27) 6.3 µm (Sample 198-1208A-6H). 28, 29.Reticulofenestra asanoi; (28) 6.6 µm (Sample 198-1208A-6H-CC), (29) 6.8 µm (Section 198-1208A-6H-5). 30.Reticulofenestra rotaria (Section 198-1208A-25X-4). 31–37. Reticulofenestra pseudoumbilicus; (31) 5.0 µm(Sample 198-1208A-27X-CC), (32) 6.1 µm (Sample 198-1208A-26X-CC), (33) 6.9 µm (Sample 198-1208A-26X-CC), (34) 7.8 µm (Sample 198-1208A-19H-CC), (36) 11.5 µm (Sample 198-1208A-28X-CC), (37) 9.2µm with grill (Sample 198-1208A-18H-CC). 38, 39. Pseudoemiliania lacunosa; (38) Sample 198-1208A-16H-CC, (39) Sample 198-1208A-4H-CC. 40. Pseudoemiliania ovata (Sample 198-1208A-9H-CC). 41, 42. Emilian-ia huxleyi (Section 198-1208A-1H-4). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 22
Plate P1 (continued). (Caption shown on previous page.)
Ret. haqii (4µm) 1208A-27X-CC
R. pseud. (5.0µm) 1208A-27X-CC R. pseud. (6.1µm) 1208A-26X-CC R. pseud. (6.9µm) 1208A-26X-CC R. pseud. (8.4µm) 1208A-23X-CC R. pseud. (11.5µm) 1208A-28X-CC
C. floridan. (10.1µm) 1208A-27X-CC Cy. floridan. (7.5µm) 1208A-32X-CCC. ?abisect. (11.4µm) 1208A-32X-CC Cy. floridan. (9.3µm) 1208A-32X-CC R. bisecta (10.6µm) 1208A-35X-CCC. floridan. 1208A-35X-CC
R. pseud. (7.8µm) 1208A-19H-CC
Ret. haqii (3.1µm) 1208A-18H-CCsmall retics (~1.7µm) 1208A-18H-CC
R. ps. w. grill (9.2µm) 1208A-18H-CC Pseudo. lacunosa 1208A-16H-CC
Ret. haqii (4.3µm) 1208A-16H-CC Ret. haqii (4.1µm) 1208A-14H-CC
Ret. haqii (4.7µm) 1208A-9H-CC
Pseudo. ovata 1208A-9H-CC
Ret. haqii-asanoi (5.4µm) 1208A-7H-CC R. haqii-asanoi (6.3µm) 1208A-6H-CC R. asanoi (6.6µm) 1208A-6H-CC
Ret. minuta (2.8µm) 1208A-5H-CC
Pseudo. lacunosa 1208A-4H-CC
Pont. multipora 1208A-18H-CCPont. discopora 1208A-9H-CC Sy. pulchra 1208A-8H-CC
Hel. carteri 1208A-8H-CC Hel. inversa 1208A-3H-CC Hel. sellii 1208A-13H-5
Pont. discopora 1208A-2H-5
Hel. granulata 1208A-34X-5
Ret. asanoi (6.8µm) 1208A-6H-5 Ret. rotaria 1208A-25X-4
Em. huxleyi 1208A-1H-4
Ca. brasiliensis 1208A-1H-4Rh. clavigera 1208A-1H-4
2µm
19 20 21 22 23 24
31 32 33 34 35 36
37 38 39 40 41 42
1 2 3 4 5 6
Helicosphaeraceae
Pontosphaeraceae
Noelaerhabdaceae
Reticulofenestra
7 8 9 10 11 12
13 14 15 16 17 18
25 26 27 28 29 30
Em. huxleyi 1208A-1H-4
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 23
Plate P2. Gephyrocapsa, Coccolithaceae, Calcidiscaceae. Taxonomic organization and concepts are general-ly comparable to those of Young and Bown (1997) and Young (1998). Images with black background arecross-polarized light images; those with light backgrounds are phase-contrast images. 1–6. Gephyrocapsa(small); (1) 1.4 µm (Sample 198-1208A-2H-CC), (2) 2.1 µm (Sample 198-1208A-9H-CC), (3) 2.1 µm (Sample198-1208A-18H-CC), (4) 2.8 µm (Sample 198-1208A-5H-CC), (5) 2.9 µm (Sample 198-1208A-4H-CC), (6)2.9 µm (Sample 198-1208A-3H-CC). 7–12. Gephyrocapsa (medium); (7–10) G. oceanica, (7) 3.8 µm (Sample198-1208A-4H-CC), (8) 3.8 µm (Sample 198-1208A-2H-CC), (9) 3.8 µm (Sample 198-1208A-1H-CC), (10)4.4 µm (Sample 198-1208A-2H-CC), (11, 12) G. caribbeanica, (11) 4.1 µm (Sample 198-1208A-8H-CC), (12)4.3 µm (Sample 198-1208A-8H-CC). 13–15. Gephyrocapsa (large); (13) G. caribbeanica, 5.0 µm (Sample 198-1208A-8H-CC), (14, 15) G. oceanica, (14) 5.1 µm (Sample 198-1208A-8H-CC), (15) 5.6 µm (Sample 198-1208A-1H-1). 16–18. Gephyrocapsa omega; (16) 5.2 µm (Sample 198-1208A-1H-CC), (17) 5.0 µm (Sample198-1208A-5H-CC), (18) 5.3 µm (Sample 198-1208A-4H-CC). 19–22. Coccolithus pelagicus; (19, 20) Sample198-1208A-30X-CC, (21, 22) Sample 198-1208A-19H-CC. 23, 24. Coccolithus miopelagicus (15.1 µm) (Sam-ple 198-1208A-31X-CC). 25–28. Calcidiscus leptoporus; (25) Sample 198-1208A-14H-CC, (26, 27) 6.3 µm(Sample 198-1208A-27X-CC), (28) 8.8 µm (Sample 198-1208A-24X-CC). 29–33. Calcidiscus tropicus; (29, 30)8.7 µm (Sample 198-1208A-13H-CC), (31) 8.8 µm (Sample 198-1208A-21X-CC), (32) 8.9 µm (Sample 198-1208A-32X-CC), (33) 7.8 µm (Sample 198-1208A-18H-CC). 34–38. Calcidiscus macintyrei; (34, 35) 11.2 µm(Sample 198-1208A-32X-CC), (36) 11.7 µm (Sample 198-1208A-26X-CC), (37, 38) 11.2 µm (Sample 198-1208A-24X-CC). 39–42. Calcidiscus premacintyrei; (39) Sample 198-1208A-33X-CC, (40, 41) 11.2 µm (Sam-ple 198-1208A-32X-CC), (42) 11.5 µm (Sample 198-1208A-31X-CC). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 24
Plate P2 (continued). (Caption shown on previous page.)
Cocco. pelagicus 1208A-30X-CC Cocco. pelagicus 1208A-19H-CC
Calci. leptoporus (6.3µm) 1208A-27X-CC
C. macintyrei (11.2µm) 1208A-24X-CC
Calci. lepto. (8.8µm) 1208A-24X-CC
C. macintyrei (11.2µm) 1208A-32X-CC
C. premacintyrei (11.2µm) 1208A-32X-CC
C. tropicus (8.9µm) 1208A-32X-CC
C. premacintyrei 1208A-33X-CC
C. tropicus (8.8µm) 1208A-21X-CC C. tropicus (7.8µm) 1208A-18H-CC
Calci. leptoporus 1208A-14H-CC C. tropicus (8.7µm) 1208A-13H-CC
small Geph. (2.1µm) 1208A-18H-CCsmall Geph. (2.1µm) 1208A-9H-CC
med. Geph. (4.3µm) 1208A-8H-CC
large Geph. (5.1µm) 1208A-8H-CC
med. Geph. (4.1µm) 1208A-8H-CC
large Geph. (5.0µm) 1208A-8H-CC
small Geph. (2.8µm) 1208A-5H-CC small Geph. (2.9µm) 1208A-4H-CC
med. Geph. (3.8µm) 1208A-4H-CC
small Geph. (2.9µm) 1208A-3H-CC
med. Geph. (4.4µm) 1208A-2H-CC
small Geph. (1.4µm) 1208A-2H-CC
med. Geph. (3.8µm) 1208A-2H-CC med. Geph. (3.8µm) 1208A-1H-CC
oceanica-typeoceanica-type
oceanica-type oceanica-typeoceanica-type oceanica-type
caribbeanica-type
caribbeanica-type caribbeanica-type
Cocc. miopelagicus (15.1µm) 1208A-31X-CC
G. omega (5.0µm) 1208A-5H-CC G. omega (5.3µm) 1208A-4H-CCG. omega (5.2µm) 1208A-1H-CC
C. premacintyrei (11.5µm) 1208A-31X-CC
C. macintyrei (11.7µm) 1208A-26X-CC
large Geph. (5.6µm) 1208A-1H-1
oceanica-type
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
2µm
37 38 39 40 41 42
Calcidiscaceae
Coccolithaceae
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 25
Plate P3. Sphenolithaceae, Incertae sedis, Ceratolithaceae. Taxonomic organization and concepts are gener-ally comparable to those of Young and Bown (1997) and Young (1998). Images with black background arecross-polarized light images; those with light backgrounds are phase-contrast images. 1–6. Cryptococcolithusmediaperforatus; (1, 2) Sample 198-1208A-24X-CC, (3, 4) Sample 198-1208A-33X-CC, (5, 6) Sample 198-1208A-32X-CC. 7. Umbilicosphaera jafari (Sample 198-1208A-18H-CC). 8–10. Umbilicosphaera sibogae si-bogae; (8, 9) Sample 198-1208A-5H-CC, (10) Sample 198-1208A-2H-CC. 11–13. Umbilicosphaera rotula; (11,12) Sample 198-1208A-27X-CC, (13) Sample 198-1208A-30X-CC. 14. Umbellosphaera tenuis (Sample 198-1208A-1H-1). 15, 16. Coronocyclus nitescens (Sample 198-1208A-33X-CC). 17. Tetralithoides symeonidesii(Sample 198-1208A-14H-CC). 18. Holococcolith (Sample 198-1208A-1H-CC). 19. Sphenolithus abies (Sam-ple 198-1208A-25X-CC). 20–23. Sphenolithus heteromorphus (Sample 198-1208A-33X-CC). 24. Sphenolithusmoriformis (Sample 198-1208A-35X-CC). 25. Florisphaera profunda (Sample 198-1208A-7H-CC). 26–28. Mi-nylitha convallis; (26) Sample 198-1208A-28X-CC, (27, 28) Sample 198-1208A-27X-CC. 29. Sphenolithus in-tercalaris (Sample 198-1208A-35X-CC). 30. Sphenolithus predistentus (Sample 198-1208A-35X-CC). 31–33. Amaurolithus bizarrus (Sample 198-1208A-22X-5). 34–38. Amaurolithus delicatus; (34) Sample 198-1208A-23X-CC, (35, 36) Sample 198-1208A-24X-CC, (37, 38) Sample 198-1208A-19H-CC. 39–42. Amauroli-thus primus; (39, 40) Sample 198-1208A-25X-CC, (41, 42) Sample 198-1208A-26X-CC. (Plate shown onnext page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 26
Plate P3 (continued). (Caption shown on previous page.)
Am. primus 1208A-26X-CCAm. primus 1208A-25X-CC
Am. delicatus 1208A-24X-CCAm. delicatus 1208A-23X-CC
Am. delicatus 1208A-19H-CC
Minylitha convallis 1208A-27X-CCMinylitha convallis 1208A-28X-CC
holococcolith 1208A-1H-CC
Umb. rotula 1208A-27X-CC
Sph. abies 1208A-25X-CC
Umb. rotula 1208A-30X-CC
Sph. heteromorphus 1208A-33X-CC Sph. moriformis 1208A-35X-CC
Sph. predistentus 1208A-35X-CCSph. intercalaris 1208A-35X-CC
Tet. symeonidesii 1208A-14H-CC
Flor. profunda 1208A-7H-CC
Umb. sib. sib. 1208A-5H-CC
Coronocyclus nitescens 1208A-33X-CC
2µm
Umb. jafari 1208A-18H-CC
Am. bizzarus 1208A-22X-5
Cry. mediaperforatus 1208A-24X-CC Cry. mediaperforatus 1208A-32X-CC
Umb. sib. sib. 1208A-2H-CC
Umbell. tenuis 1208A-1H-1
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
37 38 39 40 41
2µm
42
Sphenolithaceae
Incertae sedis
Incertae sedis
Ceratolithaceae
Hol.Umbell.
Cry. mediaperforatus 1208A-33X-CC
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 27
Plate P4. Triquetrorhabdulus, Calcispheres, Discoasteraceae. Taxonomic organization and concepts are gen-erally comparable to those of Young and Bown (1997) and Young (1998). Images with black backgroundare cross-polarized light images; those with light backgrounds are phase-contrast images. 1–6. Amaurolithusprimus; (1, 2) Sample 198-1208A-26X-CC, (3, 4) Sample 198-1208A-21X-CC, (5, 6) Sample 198-1208A-24X-CC. 7–9. Ceratolithus cristatus; (7, 8) Sample 198-1208A-19H-CC, (9) Sample 198-1208A-1H-CC. 10, 11. Cer-atolithus rugosus; (10) Sample 198-1208A-19H-CC, (11) Sample 198-1208A-14H-CC. 12, 15–17. Calcisphere(12) Sample 198-1208A-1H-CC, (15) Sample 198-1208A-18H-CC, (16, 17) Sample 198-1208A-4H-CC. 13,14. Triquetrorhabdulus rugosus (Sample 198-1208A-28X-CC). 18–20, 24, 25. Discoaster deflandrei; (18) Sam-ple 198-1208A-32X-CC, (19, 20) Sample 198-1208A-34X-CC, (24, 25) Sample 198-1208A-35X-3, 149 cm.21. Discoaster exilis (Sample 198-1208A-30X-4). 22, 23. Discoaster petaliformis (Sample 198-1208A-34X-5).26, 27. Discoaster druggii (Sample 198-1208A-35X-3, 149 cm). 28–31. Discoaster exilis (Sample 198-1208A-32X-CC). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 28
Plate P4 (continued). (Caption shown on previous page.)
D. deflandrei 1208A-34X-CCD. deflandrei 1208A-32X-CC
Discoaster exilis 1208A-32X-CC
2µm
Am. primus 1208A-26X-CC Am. primus 1208A-24X-CC
Tr. rugosus 1208A-28X-CC
Am. primus 1208A-21X-CC
Cer. cristatus 1208A-19H-CC Cer. rugosus 1208A-19H-CC Cer. rugosus 1208A-14H-CCCer. cristatus 1208A-1H-CC
calcisphere 1208A-18H-CC calcisphere 1208A-4H-CC
calcisphere 1208A-1H-CC
D. petaliformis 1208A-34X-5D. exilis 1208A-30X-4
Disco. druggii 1208A-35X-3, 149Disc. deflandrei 1208A-35X-3, 149
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17
18 19 20 21 22 23
24 25 26 27
28 29 30 31
2µm
Dicoasteraceae
Triquet. Calcispheres
Disc. deflandrei 1208A-35X-3, 149
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 29
Plate P5. Discoasteraceae II. Taxonomic organization and concepts are generally comparable to those ofYoung and Bown (1997) and Young (1998). Images with black background are cross-polarized light images;those with light backgrounds are phase-contrast images. 1–6. Discoaster challengeri; (1, 5) Sample 198-1208A-30X-CC, (2, 3) Sample 198-1208A-27X-CC, (4) Sample 198-1208A-33X-CC, (6) Sample 198-1208A-23X-CC. 7–22. Discoaster variabilis; (7–11, 13, 14) 6 (Sample 198-1208A-28X-CC), (12) Sample 198-1208A-27X-CC, (15) 5 (Sample 198-1208A-25X-CC), (16) 5 (Sample 198-1208A-29X-CC), (17) 3 (Sample 198-1208A-26X-CC), (18) 7 (Sample 198-1208A-29X-CC), (19–21) 6 (Sample 198-1208A-25X-CC), (22) 6 (Sam-ple 198-1208A-29X-CC). 23–28. Discoaster surculus; (23) Sample 198-1208A-14H-CC, (24, 25) Sample 198-1208A-13H-CC, (26) Sample 198-1208A-18H-CC, (27) Sample 198-1208A-19H-CC, (28) Sample 198-1208A-21X-CC. 29, 33–38. Discoaster brouweri; (29) Sample 198-1208A-28X-CC, (33, 34) Sample 198-1208A-17H-CC, (35, 36) Sample 198-1208A-18H-CC, (37, 38) Sample 198-1208A-27X-CC. 30. Discoaster blackstockiae(Sample 198-1208A-24X-CC). 31, 32. Discoaster calcaris (Sample 198-1208A-29X-2). (Plate shown on nextpage.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 30
Plate P5 (continued). (Caption shown on previous page.)
D. variabilis (5) 1208A-29X-CCD. variabilis (6) 1208A-28X-CC
Discoaster variabilis (6) 1208A-29X-CCDiscoaster variabilis (6) 1208A-25X-CC
D. variabilis (6) 1208A-28X-CC
D. challengeri 1208A-23X-CC
D. variabilis (5) 1208A-25X-CC D. variabilis (3) 1208A-26X-CC D. variabilis (7) 1208A-29X-CC
D. challengeri 1208A-27X-CC
D. variabilis 1208A-27X-CC
D. challengeri 1208A-30X-CC
D. surculus 1208A-14H-CC D. surculus 1208A-13H-CC
D. brouweri 1208A-17H-CC
D. surculus 1208A-18H-CC
D. brouweri 1208A-18H-CC
D. surculus 1208A-19H-CC D. surculus 1208A-21X-CC
Discoaster brouweri 1208A-27X-CC
D. challengeri 1208A-30X-CCD. challengeri 1208A-33X-CC
Discoaster calcaris 1208A-29X-2Discoaster. brouweri 1208A-28X-CC Discoaster blackstockiae 1208A-24X-CC
1 2 3 4 5 6
7 8 9 10 11 12
23 24 25 26 27 28
29 30 31 32
2µm
13 14 15 16 17 18
19 20 21 22
33 34 35 36 37 38
D. challengeri 1208A-27X-CC
D. variabilis (6) 1208A-28X-CC D. variabilis (6) 1208A-28X-CC
D. variabilis (6) 1208A-28X-CC
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 31
Plate P6. Discoasteraceae III. Taxonomic organization and concepts are generally comparable to those ofYoung and Bown (1997) and Young (1998). Images with black background are cross-polarized light images;those with light backgrounds are phase-contrast images. 1–6. Discoaster asymmetricus; (1, 3–6) Sample 198-1208A-18H-CC, (2) Sample 198-1208A-21X-CC. 7–10. Discoaster tamalis; (7, 9) Sample 198-1208A-15H-CC,(8) Sample 198-1208A-16H-CC. 10. Discoaster ?blackstockiae (Sample 198-1208A-21X-CC). 11, 12. Discoastertriradiatus; (11) Sample 198-1208A-28X-CC, (12) Sample 198-1208A-24X-CC. 13–18. Discoaster bellus (Sam-ple 198-1208A-29X-CC). 19–23. Discoaster hamatus; (19, 20, 22, 23) Sample 198-1208A-29X-CC, (21) Sam-ple 198-1208A-30X-CC. 24–34. Discoaster berggrenii; (24, 25) Sample 198-1208A-26X-CC, (26, 27) Sample198-1208A-25X-CC, (28, 29, 33, 34) Sample 198-1208A-27X-CC, (30–32) Sample 198-1208A-27X-5. 35–41. Discoaster quinqueramus; (35, 40, 41) Sample 198-1208A-26X-CC, (36, 37) Sample 198-1208A-29X-CC,(38, 39) Sample 198-1208A-25X-CC. (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 32
Plate P6 (continued). (Caption shown on previous page.)
Discoaster bellus 1208A-29X-CC
D. triradiatus 1208A-28X-CC
D. quinqueramus 1208A-29X-CC
D. triradiatus 1208A-24X-CC
Discoaster berggrenii 1208A-25X-CC
D. quinqueramus 1208A-25X-CC
Discoaster berggrenii 1208A-26X-CC
D. quinqueramus 1208A-26X-CC
D. quinqueramus 1208A-26X-CC Discoaster berggrenii 1208A-27X-CC
Discoaster berggrenii 1208A-27X-CC
Discoaster hamatus 1208A-30X-CC Discoaster hamatus 1208A-29X-CC
2µm
D. tamalis 1208A-16H-CC D. tamalis 1208A-15H-CC D. tamalis 1208A-15H-CC
D. asymmetricus 1208A-18H-CC D. asymmetricus 1208A-18H-CC D. asymmetricus 1208A-21X-CC
D. ? blackstockiae 1208A-21X-CC
Discoaster berggrenii 1208A-27X-5
Discoaster hamatus 1208A-29X-CC
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23
24 25 26 27 28 29
30 31 32 33 34 35
36 37 38 39 40 41
2µm
D. asymmetricus 1208A-18H-CC
Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC Discoaster bellus 1208A-29X-CC
Discoaster hamatus 1208A-29X-CC
Discoaster berggrenii 1208A-27X-CC
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 33
Plate P7. Discoasteraceae IV, Diatoms. Taxonomic organization and concepts are generally comparable tothose of Young and Bown (1997) and Young (1998). Images with black background are cross-polarized lightimages; those with light backgrounds are phase-contrast images. 1–11. Discoaster pentaradiatus; (1–4, 7–11)Sample 198-1208A-20H-CC, (5, 6) Sample 198-1208A-24X-CC. 12–17. Sample 198-1208A-29X-CC. 18–23. Catinaster coalitus; (18, 19) Sample 198-1208A-31X-2, (20–22) Sample 198-1208A-30X-CC, (23) Sample198-1208A-30X-2. 24–29. Catinaster calyculus; (24–27) Sample 198-1208A-30X-CC, (28, 29) Sample 198-1208A-30X-4. 30. Denticulopsis sp. (Sample 198-1208A-19H-CC). 31. Actinoptychus sp. (Sample 198-1208A-23X-CC). 32. Diatom (Sample 198-1208A-30X-CC). 33, 34. Thalassiosira sp.; (33) Sample 198-1208A-8H-CC, (34) Sample 198-1208A-4H-CC. 35. Cyclotella sp. (Sample 198-1208A-1H-CC). 36. Discoaster ?variabilis(Sample 198-1208A-28X-CC). 37, 38. Discoaster variabilis; (37) Sample 198-1208A-28X-CC, (38) Sample198-1208A-30X-CC. (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 34
Plate P7 (continued). (Caption shown on previous page.)
D. prepentaradiatus 1208A-29X-CC
D. pentaradiatus 1208A-24X-CC
Catinaster coalitus 1208A-30X-CC
Catinaster calyculus 1208A-30X-CC
D. pentaradiatus 1208A-20H-CC
D. pentaradiatus 1208A-20H-CC
Catinaster coalitus 1208A-30X-2Catinaster coalitus 1208A-31X-2
Catinaster calyculus 1208A-30X-4
Actinoptychus sp. 1208A-23X-CC diatom 1208A-30X-CCDenticulopsis sp. 1208A-19H-CC Thalassiosira sp. 1208A-8H-CC Thalassiosira sp. 1208A-4H-CC Cyclotella sp. 1208A-1H-CC
Discoaster ?variabilis 1208A-28X-CC Discoaster variabilis 1208A-28X-CC Discoaster variabilis 1208A-30X-CC
1 2 3 4 5 6
18 19 20 21 22 23
30 31 32 33 34 35
2µm
Diatoms
36 37 38
24 25 26 27 28 29
12 13 14 15 16 17
7 8 9 10 11
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 35
Plate P8. Noelaerhabdaceae, Coccolithaceae. Taxonomic organization and concepts are generally compa-rable to those of Young and Bown (1997) and Bown (2005). Images with black background are cross-polar-ized light images; those with light backgrounds are phase-contrast images. 1, 2. Chiphragmalithus barbatus(Sample 198-1208A-35X-CC); (2) side view. 3. Isthmolithus recurvus (Sample 198-1208A-36X-2, 30 cm). 4, 5.Neocrepidolithus grandiculus; (4) Sample 198-1208A-36X-2, 99 cm, (5) Sample 198-1208A-36X-CC, 1.5 cm.6. Toweius cf. T. callosus (Sample 198-1208A-36X-2, 90 cm). 7. Cyclicargolithus abisectus (Sample 198-1208A-36X-2, 3 cm). 8. Cyclicargolithus cf. C. floridanus (Sample 198-1208A-36X-2, 3 cm). 9. Reticulofenestra bisecta(8.5 µm) (Sample 198-1208A-35X-CC). 10, 11. Reticulofenestra stavensis; (10) 10.6 µm (Sample 198-1208A-35X-CC), (11) Sample 198-1208A-36X-2, 40 cm. 12. Reticulofenestra umbilicus (Sample 198-1208A-36X-2, 40cm). 13. Bramletteius serraculoides (Sample 198-1208A-35X-CC). 14. Campylosphaera sp. (Sample 198-1208A-36X-2, 99 cm). 15. Chiasmolithus consuetus (Sample 198-1208A-36X-CC, 2 cm). 16–18. Clausicoccus subdis-tichus; (16) Sample 198-1208A-36X-CC, 8 cm, (17, 18) Sample 198-1208A-35X-CC. 19, 20. Coccolithus for-mosus (Sample 198-1208A-35X-CC). 21, 22. Coccolithus pelagicus (Sample 198-1208A-35X-CC). 23, 24. Eric-sonia cf. E. robusta (Sample 198-1208A-36X-CC, 12 cm). 15. Ericsonia robusta (Sample 198-1208A-36X-CC,5 cm). 26. Hayella situliformis (Sample 198-1208A-36X-2, 3 cm). 27. ?Hughesius sp. (Sample 198-1208A-36X-CC, 1.5 cm). 28–33. Calcidiscus pacificanus; (28, 29) Sample 198-1208A-36X-CC, 1.5 cm, (30) Sample 198-1208A-36X-2, 30 cm, (31, 32) Sample 198-1208A-36X-2, 99 cm, (33) Sample 198-1208A-36X-2, 55 cm.34. Markalius sp. (Sample 198-1208A-36X-2, 55 cm). 35, 36. Coccoliths (indeterminate) (Sample 198-1208A-35X-CC). 37, 38. Chiasmolithus consuetus (Sample 198-1208A-36X-CC, 1.5 cm). 39. Reticulofenestraumbilicus (18.5 µm) (Sample 198-1208A-35X-CC). 40. Reticulofenestra stavensis (15.7 µm) (Sample 198-1208A-35X-CC). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 36
Plate P8 (continued). (Caption shown on previous page.)
Cocco. formosus 1208A-35X-CC Cocco. pelagicus 1208A-35X-CC
Claussicoccus subdistichus 1208A-35X-CC
coccolith indet. 1208A-35X-CC
R. bisecta (8.5µm) 1208A-35X-CC R. bisecta (10.6µm) 1208A-35X-CC
coccolith indet. 1208A-35X-CC
Br. serraculoides 1208A-35X-CC
Chi. barbatus side 1208A-35X-CCChiphrag. barbatus 1208A-35X-CC
Ret. umbilicus (18.5µm) 1208A-35X-CCChiasmolithus consuetus 1208A-36X-CC, 1.5
2µm
2µm
Neo. grandiculus 1208A-36X-2, 99
Ret. stavensis 1208A-36X-2, 40Cy. cf. C. floridanus 1208A-36X-2, 3Cycl. abisectus 1208A-36X-2, 3 Ret. umbilicus 1208A-36X-2, 40
Hay. situliformis 1208A-36X-2, 3
Campylosphaera sp. 1208A-36X-2, 99 Claus. subdistichus 1208A-36X-CC, 8
Calci. pacificanus 1208A-36X-2, 99
Ericsonia robusta 1208A-36X-CC, 5
Ret. stavensis (15.7µm) 1208A-35X-CC
Calci. pacificanus 1208A-36X-CC, 1.5?Hughesius sp. 1208A-36X-CC, 1.5
Ericsonia. cf. E. robusta 1208A-36X-CC, 12
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
2µm
Isthmo. recurvus 1208A-36X-2, 30
Calci. pacificanus 1208A-36X-2, 55
Calci. pacificanus 1208A-36X-2, 30
Tow. cf. T. callosus 1208A-36X-2, 90
Chias. consuetus 1208A-36X-CC, 2
Neo. grandiculus 1208A-36X-CC, 1.5
Markalius sp. 1208A-36X-2, 55
Noelaerhabdaceae
Coccolithaceae
37 38 39 40
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 37
Plate P9. Sphenolithaceae. Taxonomic organization and concepts are generally comparable to those ofYoung and Bown (1997) and Bown (2005). Images with black background are cross-polarized light images;those with light backgrounds are phase-contrast images. 1–7. Sphenolithus arthurii (Sample 198-1208A-36X-CC, 1.5 cm). 8–10. Sphenolithus ciperoensis (Sample 198-1208A-35X-5, 10 cm). 11, 12. Sphenolithus predisten-tus (Sample 198-1208A-35X-CC). 13, 14. Sphenolithus intercalaris (Sample 198-1208A-35X-CC). 15–17. Sphe-nolithus conspicuus (Sample 198-1208A-36X-2, 99 cm). 18. Sphenolithus moriformis (Sample 198-1208A-35X-CC). 19, 20. Sphenolithus pseudoradians (Sample 198-1208A-36X-2, 3 cm). 21, 22. Sphenolithus radians (Sam-ple 198-1208A-36X-2, 99 cm). 23–39. Sphenolithus villae; (23, 24) Sample 198-1208A-36X-CC, 2 cm, (25–36) Sample 198-1208A-36X-2, 99 cm, (37–39) Sample 198-1208A-36X-CC, 1.5 cm. 40–46. Sphenolithus cf.S. delphix (Sample 198-1208A-36X-2, 99 cm). 47, 48. Sphenolithus cf. S. spiniger (Sample 198-1208A-36X-2,99 cm). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 38
Plate P9 (continued). (Caption shown on previous page.)
Sph. predistentus 1208A-35X-CC
Sph. intercalaris 1208A-35X-CC Sph. moriformis 1208A-35X-CC
Sphenolithus villae 1208A-36X-CC, 1.5
Sph. ciperoensis 1208A-35X-5, 10
S. conspicuus 1208A-36X-2, 99
Sp. radians 1208A-36X-2, 99S. pseudoradians 1208A-36X-2, 3
2µm
Sp. cf. S. delphix 1208A-36X-2, 99 Sp. cf. S. delphix 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-2, 99
Sphenolithus arthurii 1208A-36X-CC, 1.5
Spheno. arthurii 1208A-36X-CC, 1.5
Sp. cf. S. spiniger 1208A-36X-2, 99
2µm
Sp. cf. S. delphix 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-CC, 2
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
31 32 33 34 35 36
37 38 39 40 41
43 44 45 46 47 48
42
Sphenolithaceae
Sphenolithus arthurii 1208A-36X-CC, 1.5Sphenolithus arthurii 1208A-36X-CC, 1.5
Sphenolithus villae 1208A-36X-2, 99
Sphenolithus villae 1208A-36X-2, 99
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 39
Plate P10. Discoasteraceae V. Taxonomic organization and concepts are generally comparable to those ofYoung and Bown (1997) and Bown (2005). Images with black background are cross-polarized light images;those with light backgrounds are phase-contrast images. 1, 2. Discoaster araneus; (1) Sample 198-1208A-36X-CC, 8 cm, (2) Sample 198-1208A-36X-CC, 2 cm. 3. Discoaster cf. D. araneus (Sample 198-1208A-36X-CC, 12 cm). 4, 5. Discoaster barbadiensis (Sample 198-1208A-36X-CC, 1.5 cm). 6. Discoaster binodosus (Sam-ple 198-1208A-36X-CC, 1.5 cm). 7–12, 21, 28. Discoaster diastypus; (7, 8) Sample 198-1208A-36X-2, 99 cm,(9–12, 21, 28) Sample 198-1208A-36X-CC, 1.5 cm. 13, 14. Discoaster lenticularis; (13) Sample 198-1208A-36X-CC, 4 cm, (14) Sample 198-1208A-36X-CC, 12 cm. 15, 16. Discoaster mahmoudii (Sample 198-1208A-36X-CC, 4 cm). 17. Discoaster mediosus (Sample 198-1208A-36X-CC, 4 cm). 18. Discoaster mohleri (Sample198-1208A-36X-CC, 12 cm). 19, 20, 24–27. Discoaster cf. D. araneus; (19, 24–26) Sample 198-1208A-36X-CC, 12 cm, (20) Sample 198-1208A-36X-CC, 14 cm, (27) Sample 198-1208A-36X-CC, 4 cm. 22. Discoasterlodoensis (Sample 198-1208A-36X-2, 55 cm). 23. Discoaster tanii (Sample 198-1208A-35X-CC). 29, 30. Dis-coaster multiradiatus (Sample 198-1208A-36X-CC, 1.5 cm). 31. Discoaster mediosus (Sample 198-1208A-36X-CC, 4 cm). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 40
Plate P10 (continued). (Caption shown on previous page.)
D. diastypus 1208A-36X-CC, 1.5
D. barbadiensis 1208A-36X-CC, 1.5 D. binodosus 1208A-36X-CC, 1.5
Discoaster diastypus 1208A-36X-CC, 1.5 Discoaster tanii 1208A-35X-CC
Discoaster multiradiatus 1208A-36X-CC, 1.5
Disc. mohleri 1208A-36X-CC, 12Disc. mediosus 1208A-36X-CC, 4Disc. lenticularis 1208A-36X-CC, 4 Disc. lenticularis 1208A-36X-CC, 12
Disc. diastypus 1208A-36X-2, 99
Disc. mahmoudii 1208A-36X-CC, 4
Disc. araneus 1208A-36X-CC, 8
Disc. cf. D. araneus 1208A-36X-CC, 14Disc. cf. D. araneus 1208A-36X-CC, 12
D. cf. D. araneus 1208A-36X-CC, 12
Discoaster cf. D. araneus 1208A-36X-CC, 12 Discoaster cf. D. araneus 1208A-36X-CC, 4
Discoaster mediosus 1208A-36X-CC, 4Discoaster diastypus 1208A-36X-CC, 1.5
1
7 8 9 10 11 12
13 14 15 16 17 18
23
24 25 26 27
28 2931
2µm
Discoaster lodoensis 1208A-36X-2, 55
Disc. araneus 1208A-36X-CC, 2
19 20 21 22
2 3 4 5 6
Discoasteraceae
30 41
D. barbadiensis 1208A-36X-CC, 1.5
Discoaster cf. D. araneus 1208A-36X-CC, 12Discoaster cf. D. araneus 1208A-36X-CC, 12
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 41
Plate P11. Rhomboaster, Tribrachiatus. Taxonomic organization and concepts are generally comparable tothose of Young and Bown (1997) and Bown (2005). Images with black background are cross-polarized lightimages; those with light backgrounds are phase-contrast images. 1–12. Rhomboaster cuspis; (1–5, 7–9) Sam-ple 198-1208A-36X-CC, 4 cm, (6, 10–12) Sample 198-1208A-36X-CC, 5 cm. 13–23, 25–27. Rhomboasterbramlettei (Sample 198-1208A-36X-CC, 4 cm); (22, 23) side view. 24. Rhomboaster bramlettei-spineus (Sample198-1208A-36X-CC, 4 cm). 28, 33. Tribrachiatus orthostylus; (28) Sample 198-1208A-36X-CC, 1.5 cm, (33)Sample 198-1208A-36X-CC, 4 cm. 29–32, 34–36. Tribrachiatus contortus; (29–32) Sample 198-1208A-36X-CC, 5 cm, (34, 35) Sample 198-1208A-36X-CC, 4 cm, (36) Sample 198-1208A-36X-CC, 2 cm. 37–39. Tribra-chiatus digitalis (Sample 198-1208A-36X-CC, 8 cm). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 42
Plate P11 (continued). (Caption shown on previous page.)
Trib. orthostylus 1208A-36X-CC, 1.5
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 5
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 5
R. bram.-spineus 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4
Trib. orthostylus 1208A-36X-CC, 4Trib. contortus 1208A-36X-CC, 5
Trib. digitalis 1208A-36X-CC, 8
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
2µm
Tribrac. contortus 1208A-36X-CC, 4 Tribrac. contortus 1208A-36X-CC, 235 36 3734 38 39
R. bramlettei side 1208A-36X-CC, 4
25 26 27 28
29 30 31 32 33
Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4 Rhomb. cuspis 1208A-36X-CC, 4
Rhomb. cuspis 1208A-36X-CC, 5
Rhomb. bramlettei 1208A-36X-CC, 4
Rhomb. bramlettei 1208A-36X-CC, 4 Rhomb. bramlettei 1208A-36X-CC, 4
Trib. contortus 1208A-36X-CC, 5
Trib. digitalis 1208A-36X-CC, 8
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 43
Plate P12. Fasciculithaceae. Taxonomic organization and concepts are generally comparable to those ofYoung and Bown (1997) and Bown (2005). Images with black background are cross-polarized light images;those with light backgrounds are phase-contrast images. 1, 2. Fasciculithus alanii (Sample 198-1208A-36X-CC, 12 cm). 3. Fasciculithus aubertae (Sample 198-1208A-36X-CC, 12 cm). 4–7. Fasciculithus bobii; (4, 5)Sample 198-1208A-36X-CC, 14 cm, (6, 7) Sample 198-1208A-36X-CC, 12 cm. 8, 9. Fasciculithus tympanifor-mis; (8) Sample 198-1208A-36X-CC, 8 cm, (9) Sample 198-1208A-36X-CC, 12 cm. 10–12, 28–33. Fascicu-lithus tonii; (10–12, 28–30) Sample 198-1208A-36X-CC, 12 cm, (31–33) Sample 198-1208A-36X-CC, 8 cm.13–16. Fasciculithus sidereus (Sample 198-1208A-36X-CC, 8 cm). 17, 18. Calcisphere; (17) Sample 198-1208A-36X-CC, 1.5 cm, (18) Sample 198-1208A-36X-2, 99 cm. 19–24. Fasciculithus fenestrellatus; (19, 20)Sample 198-1208A-36X-CC, 8 cm, (21–24) Sample 198-1208A-36X-CC, 12 cm. 25–27. Fasciculithus sp. 1(Sample 198-1208A-36X-CC, 8 cm). (Plate shown on next page.)
P.R. BOWNCENOZOIC CALCAREOUS NANNOFOSSIL STRATIGRAPHY 44
Plate P12 (continued). (Caption shown on previous page.)
calcisphere 1208A-36X-CC, 1.5 calcisphere 1208A-36X-2, 99
Fasc. alanii 1208A-36X-CC, 12 Fasc. aubertae 1208A-36X-CC, 12 Fascic. bobii 1208A-36X-CC, 14
Fasc. bobii 1208A-36X-CC, 12
Fasc. bobii 1208A-36X-CC, 12
F. tympaniformis 1208A-36X-CC, 8 F. tympaniformis 1208A-36X-CC, 12 Fasc. tonii 1208A-36X-CC, 12
Fascic. fenestrellatus 1208A-36X-CC, 12
1 2 3 4 5 6
7 8 9 10 11 12
2µm
Fascic. sidereus 1208A-36X-CC, 8
Fascic. fenestrellatus 1208A-36X-CC, 8
Fascic. sp. 1 1208A-36X-CC, 8
Fascic. tonii 1208A-36X-CC, 8Fasc. tonii 1208A-36X-CC, 12
Fasc. tonii 1208A-36X-CC, 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29
30 31 32 33
Fasciculithaceae
Fasc. alanii 1208A-36X-CC, 12 Fascic. bobii 1208A-36X-CC, 14
Fasc. tonii 1208A-36X-CC, 12
