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1 Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2013 Pliocene-Pleistocene Calcareous Nannofossil Biostratigraphy of IODP Hole 1396C Adjacent to Montserrat Island in the Lesser Antilles, Caribbean Sea, Plus Experimentally Induced Diagenesis Mohammed H. Aljahdali Follow this and additional works at the FSU Digital Library. For more information, please contact

2 THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES PLIOCENE-PLEISTOCENE CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF IODP HOLE 1396C ADJACENT TO MONTSERRAT ISLAND IN THE LESSER ANTILLES, CARIBBEAN SEA, PLUS EXPERIMENTALLY INDUCED DIAGENESIS By MOHAMMED H. ALJAHDALI A Thesis submitted to the Department of Earth, Ocean and Atmospheric Sciences in partial fulfillment of the requirements for the Degree of Master of Science Degree Awarded: Spring Semester 2013

3 Mohammed H. Aljahdali defended this thesis on March 27, The members of the supervisory committee were: Sherwood W. Wise, Jr. Professor Directing Thesis Yang Wang Committee Member William Parker Committee Member The Graduate School has verified and approved the above-named committee members, and certifies that this thesis has been approved in accordance with university requirements. ii

4 Dedicated To my family whose support has made this project possible. iii

5 ACKNOWLEDGMENTS First of all, I would like to thank and express my gratitude to my major advisor Professor Sherwood Woody Wise for his encouragement and suggestion that made this work valuable. Woody introduced me to the Nannofossil micropaleontology field back in 2010 when I was looking for an advisor to work within the foraminifera field. I took classes in his lab with almost no idea about what nannofossils were. A year later, I was invited to sail with the Integrated Ocean Drilling Program (IODP) on Expedition 340 to the Lesser Antilles; as the only nannofossil specialist yet to complete his master s degree to date. I sailed for 7-weeks with 30-high class scientists from all over the world from who I earned the name NANNO-MAN, a name denoted to me from volcanologists that never believed nannofossils could precisely age-date sediment in less than 5 minutes! It was one of the happiest moments in my life to sail on the JOIDES RESOLUTION. I would also like to thank many my committee members, Drs. Yang Wang and William Parker. Dr. Wang helped me tremendously in understanding the geochemistry of stable isotopes in marine sediment. Bill Parker, on the other hand, greatly assisted me in the process of geostatistical analyses. Drs. Abdulaziz Al-Suwailem and Thomas Missimer from King Abdullah University of Science and Technology (KAUST) generously allowed me to use the latest scanning electron microscope at KAUST, Free of charge, for the summer. Drs. Ali Behzad and Zenon Batang of KAUST were always there to help me improve the resolution of the SEM, and offer a more detailed discussion of the mathematical equations I used for quantitative analysis. The Nannofossil Research Lab Group (NRLG) in our department has many people that I am proud to be working with. I am thankful to our NRLG group: Nick Myres, Tugba Sezen, and Aaron Avery. Nick and Dr. Eric Lochner, from Physics Department, helped me use the SEM of the Physics Department at Florida State University to complete the comparisons I needed. Tugba, with her great ability in using graphic design software, developed the sketch of the nannofossil biostratigraphy summary and correlation. Aaron, one of the smartest people I ve ever met, made good discussion about the simulation of artificial late diagenesis produced by elevated temperatures. iv

6 Many thanks go to my colleagues who sailed with me on EXP 340, of the IODP. I had a wonderful time sharing ideas and meeting different cultures from all over the world. I would like to thank our Co-chief scientists Drs. Osamu Ishizuka and Anne Le Friant. Thanks go to my foraminifera specialists colleagues, Andrew Fraass, Michael Martinez-Colon and Debbie Palmer. In Saudi Arabia, I wish to express my regards to our chair professor Ali Basaham, a great marine geochemist and close friend of mine, who never hesitated to guide me and provide invaluable suggestions. I am thankful to all my colleagues in our department at King Abudlaziz University, Faculty of Marine Sciences, Department of Marine Geology. This work has been officially funded by the Integrated Ocean Drilling Program. The scholarship of the Master degree was provided from King Abdulaziz University, Faculty of Marine Sciences. Last, I would like to extend my deepest thanks to my family who encouraged me to pursue my education. My parents, indeed, deserve this work to be dedicated to them. v

7 TABLE OF CONTENTS LIST OF TABLES... ix LIST OF FIGURES... x ABSTRACT... xii 1. INTRODUCTION Calcareous Nannoplankton Classical Studies of Nannoplankton The Historical Development of Nannofossil Biostratigraphy IODP Expedition 340 to the Lesser Antilles Expedition 340, SITE The Geological Evolution of Montserrat Island SITE 1000, ODP LEG 165 in the Western Caribbean Sea Objective STUDY AREA AND METHODS Preparation Techniques Smear Slides Settling Technique Scanning Electron Microscope (SEM) Technique Nannofossil Zonation vi

8 2.3. Counting Method RESULTS Pleistocene Emiliania huxleyi Zone ( Ma) Gephyrocapsa oceanica Zone (0.29 to 0.43 Ma) Pseudoemiliania lacunosa Zone ( Ma) Helicosphaera sellii Zone ( Ma) Calcidiscus macintyrei Zone ( Ma) Pliocene Discoaster brouweri Zone (CN12d C. macintyrei Subzone; Ma) Discoaster brouweri Zone (CN12c Discoaster pentaradiatus Subzone; Ma) Discoaster brouweri Zone (CN12b Discoaster surculus Subzone; Ma) Discoaster brouweri Zone (CN12a Discoaster tamalis Subzone; Ma) Reticulofenestra pseudoumbilica Zone (CN11; Ma) Experiments on Diagenesis DISCUSSION Nannofossil Correlation vii

9 4.2. Age-Depth Plot Abnormal Diagenesis CONCLUSION APPENDICES A. ALPHABETICAL LIST OF CALCAREOUS NANNOFOSSILS CONSIDERED IN THIS THESIS B. PLATES C. COPYRIGHT PERMISSIONS REFERENCES BIOGRAPHICAL SKETCH viii

10 LIST OF TABLES Table 3.1. Nannofossil ages of the Pliocene-Pleistocene Table 3.2. Stratigraphic positions of the Pliocene-Pleistocene nannofossil datums Table 3.3. Calcareous Nannofossil Range Chart of Hole 1396C Table 3.4. Calcareous nannofossil range chart of Hole 1396C Table 3.5. Calcareous nannofossil range chart of Hole 1396C Table 3.6. Calcareous nannofossil range chart of Hole 1396C Table 3.7. Calcareous nannofossil range chart of Hole 1396C Table 3.8. Calcareous nannofossil range chart of Hole 1396C Table 3.9. Calcareous nannofossil range chart of Hole 1396C Table Calcareous nannofossil range chart of Hole 1396C Table Calcareous nannofossil range chart of Hole 1396C Table Calcareous nannofossil range chart of Hole 1396C Table 4.1. Magnetic ages constructed during Expedition 340 (Expedition 340 Scientist, 2013). 42 Table 4.2. Nannofossil ages for Hole 1000A used by Kameo and Bralower (2000) ix

11 LIST OF FIGURES Fig Location and distribution of the volcanic islands in the Lesser Antilles island arc. The outer arc consists of older volcanic islands, whereas the inner arc consists of active volcanic islands (La Friant et al., 2008). Countour lines (bathymetry; Smith and Sandwell, 1997) Fig Map of the IODP, Expedition 340 sites in the eastern Caribbean Sea (from Expedition 340 Scientists, 2013) Fig Location of Site 1396 (CARI-01C) and its topographic area (from Expedition 340 Scientists, 2013)... 9 Fig Seismic profiles of Site 1396 carried out during the Caraval cruise (Deplus et al., 2002) Fig Location of Montserrat Island in the eastern Caribbeans Sea. (1) The geological evolution of Montserrat. (2) Location of Site 1396 (from La Friant et al., 2008; Bathymetry Smith and Sandwell, 1997) Fig Site 1000 from ODP Leg 165. Black star is the location of Site (modified from Kameo and Bralower, 2000) Fig Nannofossil zonation scheme combined of Gartner (1977) and Okada and Bukry (1980) zonations Fig Summary of the nannofossil biostratiraphy of Hole 1396C Fig Comparison of scanning electron micrographs between heated samples (left) and nonheated, original sample (right). A Helicosphaera kamptneri. (Sample 6H-6, cm). B. Helicosphaera kamptneri in original Sample (14H-1, 90-92cm). C. Discoaster surculus (11H-1, 85-87cm). D. Discoaster surculus original Sample (14H-1, 90-92cm). E. Discoaster assymetricus (14H-6, cm). F. Discoaster assymetricus in original Sample (14H- 1,90-92 cm) Fig Comparison of scanning electron micrographs between heated samples (left) and nonheated, original sample (right). A. Discoaster pentaradiatus (Sample 7H-6, 73-75cm). B. Discoaster pentaradiatus in original Sample (14H-1, 90-92cm). C. Discoaster surculus (10H-5, 76-78cm). D. Discoaster surculus in original Sample (14H-1, 90-92cm). E. Calcidiscus leptoporus (5H-1, 47-49cm). F. Calcidiscus leptoporus in original Samples (10H-6, cm) x

12 Fig Comparison of scanning electron micrographs between heated samples (left) and nonheated, original sample (right). A. Discoaster assymetricus? (6H-6, cm). B. Discoaster assymetricus? in original Sample (14H-1, cm). C. Helicosphaera kamptneri (13H-5, cm). D. Helicosphaera kamptneri in original Sample (14H-1, cm). E. Reticulofenestra sp., (10H-5, cm). F. Reticulofenestra sp., in original Sample (14H-1, 90-92cm) Fig Correlation of calcareous events of Hole 1396C with Hole 1000A. Biostratigraphic summary of Hole 1000A is from Kameo and Bralower, Fig Age-depth plot by nannofossils for Hole 1396C. B refers to Base or (FO), whereas T refers to Top or (LO) Fig Integration of nannoffossil and magnetic age-model for Hole 1396C Fig Comparison between nannofossil and magnetic ages for Hole 1396C and Hole 1000A (nannofossil ages) Fig. B.1. (1) Hayaster preplexus, Sample 7H-3, cm. (2, 9-10). Ceratolithus rugosus Sample 9H-6, (3). Braarudosphaera bigelowi Sample 7H-3, cm. (4). Coccolithus pelagicus Sample 5H-3, cm. (5-6). Helicosphaera sellii Sample 6H-6, cm. (7). Pontosphera discopora Sample 9H-2, cm. (8). Pontosphaera plana Sample 6H-4, cm. (11). Calcidiscus leptoporus Sample 2H-3, cm. (12). Rhabdosphaera claviger Sample 7H-2, cm Fig. B.2. (1) Pontosphera multipora Sample 10H-5, cm. (2). Spehnolithus sp. Sample 11H-5, cm. (3). Reticulofenestra pseudoumbilica Sample 15H-6, cm. (4). Pseudoemiliania lacunosa Sample 7H-4, cm. (5,11). (cross nicoles and polarized light) Reticulofenestra ampla Sample 8H-1, cm. 6. Scyphosphaera sp. Sample 10H-2, (7-8). (polarized and cross nicoles) Reticulofenestra asanoi Sample 3H-2, (9). Gephyrocapsa oceanica Sample 2H-5, cm. (10). Gephyrocapsa caribbeanica Sample 3H-3, cm Fig. B.3. (1). Discoaster challengeri Sample 9H-CC. (2). Discoaster pentaradiatus Sample 9H- 2, cm. (3). Discoaster surculus Sample 9H-CC. (4). Discoaster tamalis Sample 9H-6, cm. (5-6). Discoaster brouweri Sample 7H-3, cm. (7). Discoaster assymtericus Sample 9H-CC. (8-9). Calcidiscus macintyrei Sample 6H-6, cm. (10-11). Oolithus fragilis Sample 7H-4, cm. (12). Florisphaera profunda Sample 7H-2, cm xi

13 ABSTRACT Integrated Ocean Drilling Program Hole 1396C, adjacent to Montserrat Island, provides a lower Pliocene to Pleistocene record of calcareous nannofossil assemblages (CN11 to CN15). The nannofossil assemblages are generally common to abundant with moderate preservation in the upper Pleistocene, and very abundant with good preservation in the lower Pleistocene and the Pliocene. The sequence was zoned via the Gartner (1977) scheme for the Pleistocene and the Okada and Bukry (1980) zonation for the Pliocene using the recent age updates from Backman et al. (2012). Sedimentation rates inferred by nannofossil biostratigraphy suggest low sedimentation rates in the Pleistocene and high sedimentation rates during the Pliocene. This sedimentation pattern was also observed at Site 1000 from Ocean Drilling Program Leg 165 in the central Caribbean Sea, suggesting a regional event caused by the closure of the Central American seaway. During the expedition (IODP, Expedition 340), selected samples from Holes 1396A and C were used to determine the sediment water content by heating them at 105 C at room pressure for 24 hours. This process produced an artificial "late diagenesis" effect with severe overgrowth features on the nannofossils. Further examination of the diagenetic progression in these samples should provide a better understanding of the progression of carbonate diagenesis in cases of high temperatures and pressures. xii

14 CHAPTER ONE INTRODUCTION 1.1. Calcareous Nannoplankton Calcareous nannoplankton (or coccolithophores) are golden-brown, unicellular marine algae, belonging to the class Haptophyceae (Haq, 1978). The term nano is originally derived from the Greek word meaning dwarf which refers to those organisms that range in size from 1 to 20 µm (Wise, 1982). Coccolithophores are unique and significant autotrophic marine algae, due to their ability to secrete individual calcareous, disk-like scales called coccoliths, which are easily distinguished from other algae in the marine realm (Haq, 1978). Every coccolithophore includes a cell that produces up to 30 interlocking coccoliths constructing a coccosphere. When the organism dies, a disintegration of coccospheres within the water column occurs leading to scattering coccoliths at the seafloor (Haq, 1978). Hence, coccoliths make up the major constituents of pelagic oozes in both the deep and marginal seas (Wise, 1982). Calcareous nannoplankton have been in existence since the Early Triassic (Bown and Young, 1998), therefore, the term calcareous nannofossil refers to those extinct forms that are preserved in the geological sequence Classical Studies of Nannoplankton The first observation of calcareous nannoplankton was made by the German biologist C.G. Ehrenberg during the examination of a chalk sample from the Rugen Island in the Baltic Sea (Ehrenberg, 1836). However, Ehrenberg regarded them as being of inorganic origin similar to chemically precipitated carbonate crystals that form in supersaturated water with respect to calcite (Ehrenberg, 1854). During the construction of the telegraphic cable in the North Atlantic, Huxley (1858) observed nannoplankton in mud samples and named them coccoliths, an informal name that has been widely used in academia (Wise, 1982). Following Ehrenberg s conclusion, Huxley (1858) considered them to be of an inorganic origin. In 1861, Sorby and Wallich, independently, examined mud samples from different localities and reached to the conclusion that coccoliths are of organic origin (Sorby, 1861; Wallich, 1861). 1

15 Huxley (1868) reexamined his original mud sample from the North Atlantic using a higher magnification in which he observed a gelatinous material he thoughts was protoplast, and concluded that coccoliths are of an organic origin The Historical Development of Nannofossil Biostratigraphy Beginning in the twentieth century, many studies began to focus on the classification and life-cycle of different species of living calcareous nannoplankton (Deflandre, 1947; Kamptner, 1941; Lohmann, 1902; Lohmann, 1909; Tan Sin Hok, 1927; and others). Lohmann (1909) introduced the term nannoplankton referring to all plankton less than 63 µm. Tan Sin Hok (1927) coined the name discoaster for rosette-shaped fossils, whereas Kamptner (1941) produced the first extensive systematic work on living coccolithophores. In the mid 50 s, calcareous nannoplankton received considerable attention as stratigraphic indicators, and were used for age assignments and global correlations (Bramlette and Riedel, 1954; Bramlette and Sullivan, 1961; Bramlette and Martini, 1964; Bramlette and Wilcoxon, 1967; Hay et al., 1967; Hay and Mohler, 1967; Levin and Joerger, 1967). Bramlette and Riedel (1954) were the first to point out the importance and usefulness of calcareous nannofossils in biostratigraphy when they delineated the stratigraphic positions of various Discoaster species. Bramlette and Sullivan (1961) recognized six biostratigraphic zones in the Paleocene-Eocene of the Lodo Formation in California. Hay and Mohler (1967) correlated the Paleocene-Eocene sequences in different localities of Europe and Americas. They were among the first to correlate nannofossil assemblages worldwide between Europe and Americas. All of these important contributions were essentially developed from land-based materials; hence, a more complete record for both the Mesozoic and Cenozoic was needed to achieve more accurate correlations and extensive zonations. The advent of the Deep Sea Drilling Project (DSDP), and the subsequent Ocean Drilling (ODP) and Integrated Ocean Drilling Programs (IODP) provided considerably more complete oceanic records of geological sequences are rich in nannofossils. These sequences have led to more global zonations and precise age assignments. There are two major zonations for the Cenozoic that are widely used in both low and mid-latitude regions: Martini (1971) and Okada and Bukry (1980). Martini (1971) introduced his "Standard" Tertiary Zonation based mainly on materials from outcrops. Okada and Bukry (1980), on the other hand, developed the low-latitude 2

16 zonation based on materials recovered from the Deep Sea Drilling Project. Gartner (1977) proposed a zonation for the Quaternary that has a higher resolution with seven zones in only a two million-year period. His zonation is widely applied at low latitudes for detailed biostratigraphic work, but the age correlations and some zones have been updated or modified by Backman et al. (2012) IODP Expedition 340 to the Lesser Antilles The writer sailed on Expedition 340 of the Integrated Ocean Drilling Program (IODP) that drilled nine sites in the Caribbean Sea (Fig. 1.1) around three active volcanic islands (Montserrat, Dominica and Martinique) in the Lesser Antilles (Fig. 1.2) between March to April The main objective of this expedition was to investigate the constructive and destructive processes (i.e., debris-avalanche emplacements) associated with volcanism along island arcs (La Friant et al., 2011). Four sites were drilled around Montserrat Island, whereas five sites were drilled to the south of the Grenada Basin of the Caribbean Sea, near Dominica and Martinique Islands. The recovered materials were mainly pure hemipelagic muds interbedded with tephra layers and volcaniclastic turbidites (Expedition 340 Scientists, 2013). In general, eight sites recovered only an upper to lower Pleistocene record of calcareous nannofossil assemblages, whereas Site 1396 was the only site to provide the longest record (Zone CN11) as indicated by the nannofossil biostratigraphy in core catcher samples during the expedition. The Lesser Antilles arc is the result of the westward subduction of Atlantic oceanic crust beneath the Caribbean plate (Fig. 1.1; Bouysse et al., 1990). This subduction formed an 800 km long arcuate chain of islands from Anguilla in the north to Grenada in the south (Bouysse, 1984; Reid et al., 1996). Minster and Jordan (1978) estimated the convergence rate of this subduction at about 2.2 cm/year. Deep Sea Drilling Project, Leg 78A investigated in detail the evolution of the Lesser Antilles arc in which Bouysee et al. (1990) covered its geodynamic evolution. North of Dominica, the arc is divided into two distinct chains of islands: (1) a chain of older volcanically inactive islands located in the outer arc, and (2) a chain of young volcanically active islands situated in the inner arc (Bouysse, 1984; Le Friant et al., 2008; La Friant et al., 2011). 3

17 Volcanism in this region has been active since 40 Ma (Bouysse et al., 1990; Reid et al., 1996). The islands located in the outer arc (Fig. 1.2; e.g., Anguilla, Antigua) were volcanically active from the Eocene to mid Oligocene (Bouysse, 1984). Those islands have extinct volcanoes bounded by shallow thick carbonate platforms called limestone caribbees (Bouysse et al., 1990). The islands located in the inner arc (e.g., Montserrat, Dominica and Martinique) have been volcanically active from the late Miocene to present, and are thus called the volcanic caribbees (Bouysse, 1984; Reid et al., 1996). This division of two different chains of islands developed when the locus of volcanism north of Dominica shifted 50 km to the west during the late Miocene due to the arrival of the aseismic ridge in the northern part of the subduction zone (Bouysse, 1990) Expedition 340, SITE 1396 Site 1396 is located at N, W in the back-arc of the Lesser Antilles in 801 meters of water (Fig 1.3). It is 35 km west of Montserrat Island, and located on a topographic high where no structural or other major complications were detected by seismic profiles (Fig.1.4). The principal objective of this site was to determine the eruptive history of Montserrat Island (Expedition 340 Scientists, 2013). Drilling at this site recovered dominantly hemipelagic mud intercalated with tephra layers and volcanoclastic sand with a recovery of 104% (Expedition 340 Scientists, 2013). Three holes were drilled using the Advanced Piston Core (APC) coring system. Hole 1396A penetrated meters of sediment. Hole 1396B penetrated to only 15 meters below seafloor (mbsf). Hole 1396C was cored to mbsf, recovering a stratigraphic section from the Pleistocene to lower Pliocene. Lithologically, Site 1396 recovered five different units (Expedition 340 Scirntists, 2013). Unit A is ~40 cm thick and primarily composed of a sequence of bioclastic rich-fine ungraded massive sand with high water content. Unit B consists of a meters sequence of tephra layers of varying thickness. The number of tephra increased below 90 mbsf to reach ~35 layers of varying thickness. Unit C is 4-meters thick medium-sand volcaniclastic sand. Unit D between 122 to mbsf consists of coarse pinkish breccias. Unit E comprises a 16-meters thick, well-sorted tephra layer interbedded with hemipelagic sediments. Of these characteristics, Hole 1396C is an excellent candidate for a detailed calcareous nannofossil biostratigraphic analysis, and for comparison and correlation with other geographic regions. 4

18 1.6. The Geological Evolution of Montserrat Island Montserrat is one of the volcanic islands in the Lesser Antilles arc. It is 61.8 mi 2 (~160 km 2 ) located at N, W (Fig. 1.5). Montserrat is a volcanic island formed from three major recent eruptions: Silver Hills, Center Hills and South Soufriers Hills-Soufriere Hills complex (Rea, 1974; Briden et al., 1979; Harford et al., 2002; La Friant et al., 2008). The Silver Hills in the north of the Island had the oldest eruption between 2600 to 1200 Ka (Harford et al., 2002). Volcanism then moved south to the Center Hills that was volcanically active between 950 to 550 Ka. From 170 Ka to present, the volcanism migrated and settled in the south of the Island, the Soufriere Hills, where it was responsible for the destruction in the last century (Harford et al., 2002). Most of the landslides and debris avalanches associated with volcanic eruptions were deposited on the southeastern flank of the island as many of our drill sites (e.g., Sites 1393, 1394, and 1395) recovered dominantly coarse volcanoclastic sand (Expedition 340 Scientists, 2013). Ash-falls, however, settled in the back-arc west to southwest of the islands SITE 1000, ODP LEG 165 in the Western Caribbean Sea Site 1000, in 916 meters of water, is located at N, W on the northern Nicaraguan Rise (NNR; Fig. 1.6; Shipboard Scientific Party, 1997). Site 1000 is one of the Ocean Drilling Program (ODP) Leg 165 sites that were drilled in the Caribbean Sea to reconstruct the Cenozoic paleoceanographic record of the basin. Two holes were drilled at Site Drilling at Hole 1000A was used the APC and Extended Core Barrel (XCB). The APC yielded a total recovery of about 103.5% which penetrated mbsf, whereas the XCB coring system penetrated mbsf with a total recovery of about 89.2%. Thus, the total recovery of both coring system is 97.3%. Hole 1000A recovered middle Miocene sediments, whereas Hole 1000B provided a complete lower Miocene section. Kameo and Bralower (2000) provided the calcareous nannofossil biostratigraphy by applying the zonation of Okada and Bukry (1980) at Sites 998, 999 and The sedimentation rate at Site 1000 is quite similar to our Site 1396 in the eastern Caribbean. Thus, Site 1000 is an excellent candidate for a correlation with Site Since our Site 1396 in the eastern Caribbean bottomed out in the lower Pliocene, only the top 160 mbsf of Hole 1000 A was used for correlation with the Hole 1396C. 5

19 1.8. Objective The principal objective of this study is to build a detailed calcareous nannofossil biostratigraphy for Hole 1396C located in the back-arc of the Lesser Antilles in the Caribbean Sea using both Gartner s (1977) zonation for the Pleistocene, and Okada and Bukry (1980) for the Pliocene with age-date updates from Backman et al. (2012). The sampling resolution of 50- cm record will provide a detailed biostratigraphy as this site recovered an appreciable number of tephra layers. A stratigraphic correlation with Hole 1000A from Leg 165 will elucidate the similarities between these sites that are located in the same basin but ~1100 miles (~1785 km) apart. 6

20 Fig Location and distribution of the volcanic islands in the Lesser Antilles island arc. The outer arc consists of older volcanic islands, whereas the inner arc consists of active volcanic islands (La Friant et al., 2008). Countour lines (bathymetry; Smith and Sandwell, 1997). 7

21 Fig Map of the IODP, Expedition 340 sites in the eastern Caribbean Sea (from Expedition 340 Scientists, 2013). 8

22 Fig Location of Site 1396 (CARI-01C) and its topographic area (from Expedition 340 Scientists, 2013) 9

23 Fig Seismic profiles of Site 1396 carried out during the Caraval cruise (Deplus et al., 2002). U1396 Fig Location of Montserrat Island in the eastern Caribbeans Sea. (1) The geological evolution of Montserrat. (2) Location of Site 1396 (from La Friant et al., 2008; Bathymetry Smith and Sandwell, 1997). 10

24 Fig Site 1000 from ODP Leg 165. Black star is the location of Site (modified from Kameo and Bralower, 2000). 11

25 CHAPTER TWO STUDY AREA AND METHODS 2.1. Preparation Techniques Smear Slides Three samples from every section at sample spacing of 50 cm as recovery allows were taken for Hole U1396C. This provided a resolution of 29 Ka for the Pleistocene, and 12.5 Ka for the Pliocene. A total of 243 samples were taken by scoop, therefore, the outermost portion of each sample was first removed prior the preparation of the smear slides to avoid any contamination via the core liner. Standard smear slides were prepared directly from unprocessed samples using standard techniques. A small amount of sediment taken by the head of a toothpick was placed on a clean cover glass, and one drop of distilled water with a ph of 8 was added. Using a wooden rounded toothpick, each sample was smeared and distributed over a cover glass in a thin evenly distributed layer. The cover glass was then dried on a hot plate for less than a minute, and the Norland Optical Adhesive #61 was used as a mounting medium. Last, all slides were cured under an ultraviolet light for at least 5 minutes Settling Technique Some samples were prepared by a settling technique, due to the generally coarse nature of the material. After removing the outermost portion of the sediment, a quarter of a pea-sized piece of sediment was placed in a clean beaker containing 12 ml of distilled water of a ph of 8. The sample was then stirred allowed to stand for two minutes. A disposable pipette was used to withdraw the upper portion of the solution from the beaker that was then poured on a clean cover glass. The cover glass was heated on hot plate until completely dry mounted with the Norland Optical Adhesive #61. 12

26 Scanning Electron Microscope (SEM) Technique The scanning electron microscope (SEM) was used to evaluate the state of preservation of calcareous nannofossils. SEM preparation technique will be used as follows: A sediment suspension in a beaker was prepared according to the settling technique described above. A disposable pipette was used to place suspension on a 18x18 mm coverslip. The cover slip was then dried on a hot plate. A double faced aluminum tape was used to attach the coverslip on a stub. Using a sputter coater, the coverslips were coated by Gold/Palladium prior to examination in the SEM Nannofossil Zonation As noted previously Gartner s (1977) calcareous nannofossil zonation scheme was used to provide a detailed biostratigraphic record for the Pleistocene, whereas the zonation of Okada and Bukry (1980) was used for the Pliocene (Table 2.1). Hole 1396C recovered an appreciable number of tephra layers for which a detailed biostratigaphic record will help to determine the ages. Most nannofossil ages used in this study to construct age-depth plots and linear sedimentation rates were compiled from the latest study of Backman et al. (2012) Counting Method Qualitative analysis was conducted by examining all smear slides under plain light, phase contrast and cross-polarized light using a Zeiss Axioscope II at a magnification of 1000x to 1250x. The identification of calcareous nannofossils in this study followed the taxonomy of Young (1998) and Perch-Nielsen (1985). Two traverses were used to count and to make sure rare species were recorded. The estimates of the overall nannofossil abundance were given the following letter codes: V= very abundant (more than 10 nannofossils /field of view). A= abundant (1-10 nannofossils/field of view). C= common (1 nannofossil/2-10 fields of view). F= few (1 nannofossil/more than 10 field of view). 13

27 R= rare (1 nannofossil/ more than 100 fields of view). B= barren (no nannofossils/ 200 fields of view). The average state of preservation of the nannofossil assemblage was determined as follows: VG= very good (no evidence of dissolution and/or overgrowth; no alteration of primary morphological characteristics, identification is possible). G= good (little or no evidence of dissolution and/or overgrowth; primary morphological characteristics are slightly altered identification is possible). M= moderate (specimens exhibit some etching and/or overgrowth; primary morphological characteristics sometimes altered; however, most specimens are identifiable to the generic level). P= poor (specimens are severely etched or exhibit overgrowth; primary morphological characteristics largely destroyed; fragmentation has occurred; specimens cannot be identified at both specie and generic level). The relative abundance of individual species was estimated by the methods of Hay (1970): VA = Very Abundant (over 10 specimens per field of view). A = Abundant (1-10 specimens per field of view). C = Common (one specimen per 2 to 10 fields of view). F = Few (one specimen per 11 to 100 fields of view). R= rare (1 to 2 specimens per slide). 14

28 CHAPTER THREE RESULTS A 140-meter sequence of hemipelagic mud rich in nannofossils and interbedded with tephra layers was recovered from Hole 1396C. Based on a qualitative analysis, twenty-two genera and forty-five species were identified in this material. A range chart showing the distribution and relative nannofossil abundances is given in Table (3.3). In this hole, nannofossils are common to very abundant and exhibit moderate to good preservation. The upper sequence contains some samples that are moderately affected by diagenesis with dissolution and/or reprecipitation in only a few species. The lower sequence, on the contrary, is characterized by abundant nannofossils and excellent preservation. Samples slightly affected by early diagenesis in the upper sequence are normally show a drop in nannofossil abundance and an increase in fragmentation. In general, the slight diagenesis in the upper sequence did not hinder the identification of most of the taxa at the species level. The number of reworked species, on the other hand, is minimal; therefore the recognition of zonal datums was not difficult. The Gartner (1977) zonation proved to be applicable in Hole 1396C, allowing for better resolution in the Pleistocene. Only the Small Gephyrocapsa Zone could not be consistently recognized, owing to their small sizes and susceptibility to dissolution. Thus, the Pseudoemiliania lacunosa Zone was expanded to include this zone (Fig. 3.1). The zonation of Okada and Bukry (1980) was applied for the Pliocene (CN12 to CN11), and all zones were easily recognized throughout the lower sequence. Subzones of CN11 (e.g., Discoaster asymmetricus and Sphenoloithus sp.), however, could not be recognized because the Base acme of Discoaster asymmetricus was not observed as the marker species displayed a uniform abundance pattern without an abrupt increase in the lower sequence. Nannofossil ages compiled from the latest study of Backman et al. (2012; Table 3.1) were used to construct age-depth plots and linear sedimentation rates for Hole 1396C. The stratigraphic position of the nannofossil datums and their ages are listed in Table (3.2). The summary of the nannofossil biostratigraphy of Hole 1396C is found in Fig (3.3). Based on those ages, a graph showing the FO and the LO of every datum was constructed (Fig. 4.2 in 15

29 discussion). Systematically, small Gyphrocapsa species include the following species due to their small sizes that can be difficult to distinguish in the light microscope: G. ericsonii, G. omega, G. muellerae, and G. lumina Pleistocene The Pleistocene assemblage is characterized by dominant Gephyrocapsa oceanica, G. caribbeanica, small Gephyrocapsa, Calcidiscus leptoporus, Pseudoemiliania lacunosa, Umbellosphaera tenuis, Helicosphaera and Reticulofenestra species. Helicosphaera species are very dominant throughout the sequence ranging from common to abundant. Florisphaera profunda occurs sporadically, few to common. The overall nannofossil preservation is moderate to good with a variety of abundances Emiliania huxleyi Zone ( Ma) Samples from 1H1, cm (0.6 mbsf) to 1H4, cm (5.45 mbsf) were assigned to the Emiliania huxleyi Zone (CN15; Okada and Bukry, 1980) due to the presence of E. huxleyi. This interval is characterized by moderate to good preservation with no significant reworked species. Helicosphaera inversa, a useful datum in the Quaternary, was not found probably due to the state of preservation along with the drop in the nannofossil abundance in the upper sequence. Because of the slightly moderate state of preservation and fluctuation in E. huxleyi abundance, the acme of E. huxleyi acme could not be recognized. The FO of E. huxleyi (0.29 Ma), however, lies between Samples 1H-4, cm to 1H-4, cm. The main assemblage in this zone is characterized by abundant G. oceanica, G. caribbeanica and small Gephyrocapsa; common to few E. huxleyi, Ceratolithus cristatus, Rhabdosphaera clavigera, F. profunda and Pontosphaera plana Gephyrocapsa oceanica Zone (0.29 to 0.43 Ma) Samples 1H-4, cm (5.78 mbsf) through 1 HCC (8.39 mbsf) contain neither E. huxleyi, nor Pseudoemiliania lacunosa; hence, they were assigned to the Gephyrocapsa oceanica Zone. Nannofossils are common to abundant and exhibit moderate to good preservation. The overall assemblage consists mainly of abundant G. oceanica, G. caribbeanica, small Gephyrocapsa, Reticulofenestra and Helicosphaera species, and common to few C. leptoporus, U. tenuis, R. claviger and F. profunda. 16

30 Pseudoemiliania lacunosa Zone ( Ma) This zone encompassed both the P. lacunosa and small Gephyrocapsa Zones. Samples from 2H-1, cm (8.97 mbsf) to 3H-7, cm (27.53 mbsf) were assigned to the P. lacunosa Zone, based on the presence of P. lacunosa. Nannofossils are abundant to very abundant with moderate to good preservation. This zone yielded an early Pleistocene assemblage dominated by abundant P. lacunosa, Calcidiscus leptoporsu, Dictyococcites productus, small Gephyrocapsa, G. oceanica, G. caribbeanica, Helicosphaera and Reticulofenestra sp., common to few F. profunda, Oolithus and Pontosphaera sp. Reticulofenestra asanoi, a very useful datum in the early Pleistocene, was observed between Samples 2H-5, cm (15.05 mbsf) and 3H-3, cm (21.29 mbsf). The age of this interval lies between the FO of R. asanoi (21.29 mbsf; 1.16 Ma) to the LO of the same marker (15.05 mbsf; 0.85 Ma). The main assemblage in this interval consists of abundant P. lacunosa, G. oceanica, and Helicosphaera sp.; common small Gephyrocapsa sp., F. profunda, and few G. parallela and Oolithus species. Only one sample showed a reworked species from the early Pliocene, Sample 3H-1, (19.21 mbsf), in which Sphenolithus abies/neoabies were observed. The FO of G. parallela (1.06 Ma), another useful datum in the early Pleistocene, occurs between Samples 3H-2, (20.49 mbsf) and 3H-1, (19.21 mbsf) Helicosphaera sellii Zone ( Ma) Samples from 3HCC (27.92 mbsf) to 4H-2, cm (29.45 mbsf) were assigned to the Helicospahera sellii Zone, based on the presence of H. sellii and the absence of Calcidiscus macintyrei. Helicospahera sellii was found rare to few even though a lower magnification (e.g., 40x) was used to observe the overall abundance of this marker. Overall, H. sellii is few to rare throughout the sequence. The LO of H. sellii (1.24 Ma) lies between Samples 3H-7, cm (27.53 mbsf) and 3HCC (27.92 mbsf). The general preservation in this interval is characterized by moderate to good preservation with an assemblage characteristic of the early Pleistocene with abundant to common Helicosphaera sp., C. leptoporus, G. oceanica, G. caribbeanica, P. lacunosa, small Gyphrocapsa and Reticulofenestra species; few to rare Oolithus fragilis, Pontosphaera discopora, and Discosphaera tubifer. Due to fluctuations in preservation, F. profunda is absent in this interval. At the base of this zone, the FO of G. oceanica (1.59 Ma) occurs between Samples 4H-2, cm and 4H-2, cm. 17

31 Calcidiscus macintyrei Zone ( Ma) Sediments from Samples 4H-2, cm (29.93 mbsf) through 4H-7, cm (36.91 mbsf) were assigned to the Calcidiscus macintyrei Zone due to the presence of C. macintyrei with no record of Discoaster brouweri. The LO C. macintyrei (1.60 Ma), which defines the top of this zone, lies between Samples 4H-2, cm and 4H-2, cm. The overall preservation in this interval is moderate to good with abundant to very abundant nannofossil assemblages. This zone yielded an assemblage mainly of abundant Reticulofenestra and Helicosphaera sp., H. preplexus, Oolithus sp., and Pontosphaera sp., whereas H. sellii, D. productus and U. tenuis were recorded as few to rare. Within this zone, the FO of G. caribbeanica (1.71Ma) lies between Samples 4H-5, 101 cm (34.41 mbsf) and 4H-5, 53 cm (33.93 mbsf) Pliocene Discoaster brouweri Zone (CN12d C. macintyrei Subzone; Ma) This zone was assigned to Samples 4HCC (37.35 mbsf) through 6H-2, cm (48.80 mbsf) based on the presence of both C. macintyrei and D. brouweri, and the absence of D. pentaradiatus. The LO of Discoaster brouweri (1.93 Ma), a marker that defines the top of Zone CN12d, occurs between Samples 4H-7, 49 cm and 4HCC. Nannofossils in this interval are generally abundant to very abundant and exhibit excellent preservation. The main assemblage in this zone is characterized by abundant small Gephyrocapsa, P. lacunosa and Reticulofenestra sp., common D. brouweri, C. macintyrei, C. leptoporus, Helicosphaera sp, and few.d. triradiatus, and Coccolithus pelagicus. The latter species was only recorded in three samples as few (5H-3, cm, 6H-2, cm, and 6H cm). Florisphaera profunda was common to its highest occurrence at the base of this zone Discoaster brouweri Zone (CN12c Discoaster pentaradiatus Subzone; Ma) Samples from 6H-2, cm (49.22 mbsf) to 6H-5, cm (53.73 mbsf) were assigned to this zone based on the presence of D. pentaradiatus and D. brouweri in the absence of D. surculus. The LO of D. pentaradiatus (2.39 Ma), which defines the top of this zone, lies between Samples 6H-2, 90 cm to 6H-2, 132 cm. 18

32 The overall preservation in this zone is generally good with nannofossil abundance ranges from abundant to very abundant. This zone is characterized by abundant small Gephyrocapsa, P. lacunosa, and small Reticulofenestra sp. Calcidiscus macintyrei, C. leptoporus, H. preplexus, Helicospahera sp., D. asymmetricus, D. triradiatus, were common to few. Florisphaera profunda was also found in this zone ranging from common to abundant Discoaster brouweri Zone (CN12b Discoaster surculus Subzone; Ma) Samples 6H-6, cm (54.31 mbsf) through 7H-5, cm (63.01 mbsf), based on the presence of D. surculus were assigned to this zone. The LO of D. surculus (2.53 Ma) that defines the top of this zone lies between Samples 6H-5, 131 cm to 6H-6, 41 cm. Overall preservation in this zone is excellent and abundances range between abundant to very abundant. The assemblage consists of common to abundant Helicosphaera and Reticulofenestra sp., few C. macintyrei, D. asymmetricus, D. brouweri, D. pentaradiatus, H. preplexus, and Oolithus fragilis. Florisphaera profunda is present in this interval ranging between very abundant to abundant. Coccolithus pelagicus is rare in Sample 6H-7, cm (55.76 mbsf) and few from Samples 7H- 1, cm (57.21 mbsf) to 7H-5, cm (63.01 mbsf) Discoaster brouweri Zone (CN12a Discoaster tamalis Subzone; Ma) Samples 7H-5, cm (63.30 mbsf) to 11H-1, cm (94.92 mbsf) were assigned to this zone based on the presence of Discoaster tamalis because neither Sphenolithus sp., nor R. pseudoumbilica was found. The LO of D. tamalis (2.78 Ma) that marks the top of this zone occurs between Samples 7H-5, cm and 7H-5, cm. Nannofossils are abundant to very abundant and exhibit excellent preservation. This zone is quite long thickness of ~20 m and is characterized by common C. macintyrei, D. productus, D. brouweri and D. pentaradiatus plus few D. surculus, D. triradiatus, D. variabilis, D. challengerii and Oolithus antillarum. Florisphaera profunda is abundant to very abundant. Helicosphaera sellii was observed sporadically as few to rare. Reticulofenestra ampla is a useful datum whose LO (2.78 Ma) occurs before the LO of D. tamalis (2.76 Ma), between Samples 7H-5, cm to 7H-6, cm. 19

33 Reticulofenestra pseudoumbilica Zone (CN11; Ma) This zone was assigned to Samples 11H-2, cm (96.24 mbsf) to 15HCC (140.0 mbsf) based on the presence Sphenolithus spp. the LO of Sphenolithus spp. (3.61 Ma) is used here for the top of this zone because the LO of R. pseudoumbilica (3.80 Ma) lies between Samples 12H-2, cm and 12H-2, cm. Sphenolithus spp were used as the main marker for our Zone CN11 because R. pseudoumbilica is absent only in the middle Pliocene. The recognition of the CN11 subzones was difficult because the base of the acme of Discoaster asymmetricus could not be recognized, even though this zone has a thickness of ~40 m, the longest zone in this study. Thus, the zone CN11 was utilized without subzones. Nannofossils in this zone are abundant to very abundant with excellent preservation. The main assemblage of this zone is characterized by abundant F. profunda, Sphenolithus spp. and small Reticulofenestra sp.; common to few D. brouweri, D. challengerii, D. pentaradiatus, D. tamalis, D. varibilis, P. lacunosa and Helicosphaera sp. Reticulofenestra Pseudoumbilica was observed as few to common. Coccolithus pelagicus was recorded as rare in this zone. Within this zone, the FO of P. lacunosa lies between Samples 12H-7, cm and 12HCC. The drilling in this hole was abandoned at mbsf depth; therefore Zone CN11 was not completely recovered. Consequently, the age 4.37 Ma was arbitrary placed as the base of Zone CN11. 20

34 Table 3.1. Nannofossil ages of the Pliocene-Pleistocene. Event Zone (Base) Age (Ma) Reference B Emiliania huxleyi CN Rio et al. (1990) T Pseudoemiliania lacunosa CN14b 0.43 Backman et al. (2012 T Reticulofenestra asanoi _ 0.91 Raffii (2002) B Gephyrocapsa parallela _` 1.06 Raffii (2002) B Reticulofenestra asanoi _ 1.14 Raffii (2002) T Helicosphaera sellii _ 1.24 Raffii et al. (1993) B Gephyrocapsa oceanica _ 1.59 Raffii (2002) T Calcidiscus macintyrei _ 1.60 Raffii (2002) B Gephyrocapsa caribbeanica CN13b 1.71 Raffii (2002) T Discoaster brouweri CN13a 1.93 Curry, Shackleton et al. (1995) T Discoaster pentaradiatus CN12d 2.39 Curry, Shackleton et al. (1995) T Discoaster surculus CN12c 2.53 Curry, Shackleton et al. (1995) T Dicoaster tamalis CN12b 2.76 Curry, Shackleton et al. (1995) T Reticulofenestra ampla _ 2.78 Sato et al. (1991) T Sphenolithus spp. CN12a 3.61 Curry, Shackleton et al. (1995) T Reticulofenestra pseudoumbilica _ 3.82 Curry, Shackleton et al. (1995) Table 3.2. Stratigraphic positions of the Pliocene-Pleistocene nannofossil datums. Event Zone (Base) Age (Ma) Core, section, interval (cm) Depth (mbsf) B Emiliania huxleyi T Pseudoemiliania lacunosa T Reticulofenestra asanoi B Gephyrocapsa parallela B Reticulofenestra asanoi T Helicosphaera sellii B Gephyrocapsa oceanica T Calcidiscus macintyrei B Gephyrocapsa caribbeanica T Discoaster brouweri T Discoaster pentaradiatus T Discoaster surculus T Dicoaster tamalis T Reticulofenestra ampla T Sphenolithus spp. T Reticulofenestra pseudoumbilica CN15 CN14b CN13b CN13a CN12d CN12c CN12b _ CN12a _ H4, 93 to 1H5, 58 1HCC to 2H1, 57 2H4, 117 to 32H5, 65 3H1, 129 to 3H1, 109 3H3, 37 to 3H3, 87 3H7, 61 to 3HCC 4H2, 101 to 4H3, 97 4H2, 101 to 4H2, 103 4H5, 51 to 4H5, 101 4H7, 49 to 4HCC 6H2, 88 to 6H2, 132 6H5, 131 to 6H6, 41 7H5, 109 to 7H5, 140 7H5, 138 to 7H6, 48 11H1, 100 to 11H2, 84 12H2, 100 to 12H2,

35 Fig Nannofossil zonation scheme combined of Gartner (1977) and Okada and Bukry (1980) zonations. 22

36 Table 3.3. Calcareous Nannofossil Range Chart of Hole 1396C. Age Early Pliestocene Late Pleistocene Nannofossil s zones or subzone Emiliania huxleyi zone Gephyroca psa oceanica zone Pseudoemil iania lacunosa zone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Braarudosphaera bigelowii Calcidiscus leptoporus Ceratolithus cristatus Calciosolenia murrayi Dictyococcites productus Discophaera tubifer Emilianina huxleyi Florisphaera profunda Gephyrocapsa caribbeanica Gephyrocapsa oceanica Gephyrocapsa parallela small Gephyrocapsa H-1, VA M. C F. F F A F C A. A C C C. C. C C. C.. A C C. A. C C H-1, VA M R C F... A F A A. A C C C. F C C R. F.. A. C. A. C C H-2, C M. C... R R. A A. A. C C C.. F. F. C. A A H-2, C M..... R F. C C. C F C C. C F C F. C.. F F F... F F H-2, A G. C. R.. C. A A. A. C... F F.. F.. A. C. C. C C H-3, C M. C.... C. A A. A R F.... R.. F.. C. R r C. C R H-3, A G. C. F F. A F C A. A C C C. F. F F.... A F F. A. F C H-4, A G. F. F F. F. A A. A. C F C. C. A. C C H-4, A G. F. C F. F F C A. A C A C. F C C..... A C C. C. F H-4, A G. F. C F.. C C A. V F A C. F F C C. F.. C F F. C. F A H-5, C M. F.. C.. A C A. A. C F. F F C F. F.. A A.. C. F C H-5, A M. C.. F.. F A A. A. C.. F. F..... A C C... C F H-6, A M. C. F F F. C C A. A C C F. F F C F. C r. C C C. A. F A H-6, C M. C. F... C C A. A F A F... C C r F r. F C C. A.. A H-CC A P. C.. F... A A. A F C... F F C. F r. C C.. A. F A H-1, A P. C.. F.. C F C. A F C C.. F C C. F F. A C.. C. F C H-1, C M. A.. C F.. C A. A. C C.. C F C.. F. C A C. A.. A H-1, A M. C.. C F.. C C. A F C.... F C. F F. A A C. C. F C H-2, C M. C.. F F.. F C. A. C.... F.. F F. A F.. C. A C H-2, C M. C.. F... C C. A F C C... F.. C F. A A.. C. F C H-2, VA M R A. F C F. C C A. A C A F.. C F.. F F. A C F. C. F A H-3, A M. A. F F F. A A A. A C A C.. F C.. C F. A A C. C. C C H-3, C M. A. F F F.. C C. A F C C... F.. C F. A C.. C.. A H-3, C P. C... C. C C A. A. A C... F.. C F. A C.. C.. A H-4, A M. C.. C.. C C A. A. C C.. C F.. C A. A C C. A.. A H-4, C G. C. F F F. C C A C A C A... F... C A. A C C. C. F C Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Helicosphaera wallichii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera multipora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra asanoi Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera Sphenolithus abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae 23

37 Table 3.4. Calcareous nannofossil range chart of Hole 1396C Age Early Pleistocene Nannofossils zones or subzone Pseudoemiliania lacunosa zone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Braarudosphaera bigelowii Calcidiscus leptoporus Coccolithus pelagicus Calciosolenia murrayi Dictyococcites productus Discophaera tubifer Florisphaera profunda Gephyrocapsa caribbeanica Gephyrocapsa oceanica Gephyrocapsa parallela H-4, C M. F. F... A A. F. F F... C F F. A C C. C.. C H-5, V M. A. C C.. C A C A F C C. C. F F A C A A C. C.. A H-5, V G. C. C C F. A A C V A C F. C C F C A F A A C. C.. C H-6, C M. C A. A C A..... F A F C C C. C.. A H-6, V M. A.. F. C A A. A F F F... F C A F A C C. C. F A H-7, V M. A. C C. C C A C V F A C. C F. F A C A A C. C. F C H-7, C P. C.. C... A C A. F..... C F F C C C. A. F A H-1, A M. A... C C A A C V F C.. F. C C A C A A A. A.. A H-1, A G.... F C. C A. A C A C. C C C C C C A A A. A.. A H-1, A G. C. C F.. C A C A F A... C. C C C A C A r C.. A H-2, A M. A.. C F.. A. A. A A.... C A C C A A. A. F C H-2, V M. A. C.. C C. F A F A C.. C. C A C A A C. C.. C H-3, V M. A.. C.. C A C A F C C. C F F C C F A A C. C.. A H-3, V G R A. C C F V F F. V. A F. A A C C A. A A A. C F. A H A M. A. F... F F. V C A F.. F C F A. A A A. C F. A H-4, V G. C. C C.. F C F V C A C. C C F F A. A C C. C R. C H-4, V G. A.. C.. F C. V F A C.. F F C A. A A C. C. C A H-4, V M. C. F C.. F C F V. A F. C.. F C. A C C. C F C C H-5, V M. A.. C C A A A. V C A C. C F C C A. A A A. C. A A H-5, V M R A. C F F C A A. V F C C. F C C F A. A A A. A R C A H-6, A M. A. C C F. A C. A C A C. C F F F A. A C A. A R A A H-6, V G. A. F C F. C A. A C A C. F C C C A. A C A. A F C A H-6, V M. A. C C F. C A. A C A C. F F C C A. A C C. A F A A H-7, C M. C.. F.. C.. A. A C... F F A. A A C. C. C A H-7, A M. C.. C. F A A. A C C C R F F C C F. A C C. A R C A small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra asanoi Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae 24

38 Table 3.5. Calcareous nannofossil range chart of Hole 1396C Age Late Pliocene Early Pleistocene Nannofossils zones or subzone H. sellii Calcidiscus macintyrei CN12d Hole 1396C Depth (mbsf) Sample (coresectioninterval in cm Abundance Preservation Braarudosphaera bigelowii Calcidiscus leptoporus Calcidiscus macintyrei Coccolithus pelagicus Calciosolenia murrayi Dictyococcites productus Discoaster brouweri Discoaster triradiatus Disosphaera tubifer Florisphaera profunda Gephyrocapsa caribbeanica Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora H-CC A M. A... F.... A C A. A C R C F C. C A A F C. A F C A H-1, A M. C... F.. F. A C C. C C F.. F. C A A C C... C A H-1, A M. C.. F C.... A C A F C C F F. F. F A A C C. A. C A H-2, C P. C... F.... A F A F F C R.... F C A C C. F. C A H-2, V M. C r. F C.. F F A. A C A C R C C C. F A A C C. C. C A H-3, V M. A R. F C.... C. A C A C R C F F. C A A C C. A. C A H-3, V M. A F.. C.... C. A C C C R C F C. C A C C C. A R C A H-4, A M. C F. F F.. F. F. A C C F.. F F. F A A C C. C. F A H A M A R. F F A C A C F C C F. C A A C C. A. F A H-5, A M. C F. F F... C F. C F C F R F F F. C C A C C. C. R A H-5, V M. C F. F C A C C C R C F F. C A A C C. A. F A H-5, A M. C F. F C... C.. C F C C F F C F. C A A C C. A. F A H-6, A M. C F. F C... F.. A F C F R A F F. C A A C.. C. F A H-6, V M. F C.. F A C C C. C F F. C A C C C. A F F A H-7, A M. C C.. F C F C F. C F C. F C C A C. C R F A H-7, V M. C F. F F.. F C.. C F C C R C F F. F A A C A. A. F A H-CC A M. C F.. A F F C C.. A F C C F C C F. C A A C A. C C. C H-1, V M. A F.. C C F F C.. A C F C R C. F. C A A C C. C F F A H-1, A M. F F. F C F F F... C C C C. C F F. F A A A C. C F F A H-2, C M. F R.. C R R. C.. A F F F. F F F. F F A C C. C.. C H-2, C P. A F.. C R..... C. C... F.. F C C C F. C. R C H-3, V G. A C. F C C F.... C F F C. C C F. F A A C C. C F. A H-3, V M. C F F C C F F F F.. C C C C. C. F. F A A C C. A F F C H-4, V G. A C. C C C F.... A. C C. F C C. F A A C C. A F C A H-4, V G. F C. C C C F F F.. C C C C. C C F. C A A C C. C F. A H-5, A M. F C. C C C F. C.. C C C C.. F F. F A A C C. C.. C Gephyrocapsa oceanica small Gephyrocapsa Pontosphaera multipora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae 25

39 Table 3.6. Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresectioninterval in cm Abundance Preservation Braarudosphaera bigelowii Calcidiscus leptoporus Calcidiscus macintyrei Coccolithus pelagicus Calciosolenia murrayi Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster pentaradiatus Discoaster surculus Discoaster triradiatus Discophaera tubifer Florisphaera profunda G. caribbeanica small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera multipora Pontosphaera plana P. lacunosa Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae Late Pliocene CN12d CN12c CN12b H-5, V M. C C. C F. C.. F... A F C C. C. F. C A A A C. C.. A H-6, V G. C C. C F. C.. F. C. C F C C. C F C. F A A A C. A F. C H-6, V G. C C. C C. C.. F. C. C F C C. C F F. F A A C C. C.. C H-7, V G. C C.. C. C.. F. C. C F C C R C F C. C A A C C. C F. A H-CC V M. C C. C F. C.. F. F. C F C C F. F F. C A A C C. C F. A H-1, V M. C C. F F. C.. F F C. A F C A. F F F. C A A A C. C F F C H-1, V G. C C. F F. A.. F F V. C F C C F C C C F C A A C C. C F. C H-2, V G. C C F F C. A.. F C A. C C C C. C C C F C A A C C. A F. A H-2, V G. F C F F F. C.. F. V. C F C C. C F F F C C A A F. C F F A H-2, V M. C C F C C F A C. F C.. A C C C F C C F F F A A C A. A F. A H-3, A M. C C. F C F F F. F F C. A F C C. A F C F C A A C C. F F R C H-3, V M R C F. F F F F F. F. F. A F C A F F F F. C A A C C. A F F C H-3, A M. C F R F C F C F. F F C. A C C C. C F F F F A A C C. C F. C H-4, V M. A F. C F C F C. F. C. A C C C. C F F. F A A C C. C F. A H-4, A M. C F. C F F C C. F. C. A C C C. C F C. C A A C C. C F. C H-4, A M. C F. C C F F C. F. C. A F C C. C F C F C A C F C. F C. C H-5, V M. C F. C C F F C. F F A. A F C C F C F F F C A A C C. A F. C H-5, A M. C F. F F F C C. F. C. C C C C. F F F. F A A C C. F F. C H-5, A G. C C.. F C C C. F. C. C F C F. C C F F F A A C C. C.. C H-6, V M. C C. C C C C C F F. C. A F C C C F. F F C A A C C. A F. C H-6, V G. C F. F C C F C F F. V. A F C C F C C F. C A A F C. C F. C H-7, A G. C C R C F C F C F F. A. A C C C F F C F F F A A C C. C F H-CC V M. C C. C C C C C C F. F. C C C C. F F F. F A C F C. C F. C H-1, V G. C C F F F C C C F F F V. A F C C C F F F. F A A C C. F F. C H-1, A G. C F. F C F F F F F. A. A F C C F F F F F F A A C C. C F. C H-1, A G. C C F. A F F C F F. A. C F C C F F F F. F A A C C. C. C 26

40 Table 3.7. Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Braarudosphaera bigelowii Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster pentaradiatus Discoaster surculus Discoaster tamalis Discoaster varibilis Discoaster triradiatus Discophaera tubifer Florisphaera profunda small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra ampla Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera Syracosphaera pulchra Scyphosphaera sp. Umbilicosphaera sibogae Late Pliocene CN12b CN12a H-2, V G F C F.. F C F F C C.. F. A C C C C. C F F F A. A A C C F C H-2, V G. C C F F F C F C A C.. F. V C F C C C F C F F A. A C C C F C H-2, A M. C F F. F C F C F C.. F. A A F C C F F F F F A. A A C A F C H-3, V G. C F F. F C C C C C.. F. A C F C C C C C. F A. A C C F F C H-3, V G. C C F.. C C A C F.. F. V C C C C. C C F F A. A C C A. C H-3, V G R C C F.. C C C C C.. F. A C C C C C F C C F A. A C C C F C H-4, A M. C F... C F C F F.. F. A A C C C. F F F C A. A C C C F C H-4, V M. C F C. F F F C C F.. F. A C C C C. F F F C A. A C C A F C H-4, A M. C. C. F C F C C... F F A A F C C. F C. F C. A C C C F C H-5, V G. A C F. F C C C C C.. F. V A F C C C F C C C A. A C C C F C H-5, A G. C C F. F C F A C C.. F F V A C C C F F C F F A. C C C C F C H-5, V G. C C F. F C C C C C F. F. V A C C C F F F C C A.. A C C F C H-6, V G. C C F.. C C C C F F. F C V C C C C C F C F. A A A C C C. C H-6, V G. C C F. F C F C F F F. F. A C F A C F F F F F A C A C C C. A H-6, V G. C C C R. F C C C F C. F F V C F C C C F C C C A C A C C C F A H-7, A G. C C C.. C C C C C C. F F V C C C C C F C F C A F A C C C F A H-7, A M. C F F.. C F C F F F. F. A C C C C F C C F F A F A C C C C A H-CC A M. C C... F C C C F C. F F F C C C C F F F. C F F A C C C C C H-1, A G. C C C F. C C A C F F. F. A C C F C.. F. C F C A C C F F C H-1, A G. C C. F. C C C C F F. F. A C F F C. F F C F F C A C C C F C H-1, C G. C C F.. C C C C R R... A C F C C F F F. F A C A C C C F H-2, C G. C C F.. F A C C F F F F. V C F C C F C C C C A F C C C C F C H-2, V G. C F... C A C C F C F F. V C C C C F C C F C F C C C C C F C H-2, A M. C F F. F F C C C C F F F. A C C C C. F C. C C F C C C C F C H-3, A G. C F... C C C C F F R F. A C C C C F C C F F C A C F C C F C H-3, V G. C C F F R C C C C C F F F. V C C C C F C F C F C A A C C C. A 27

41 Table 3.8. Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster challengeri Discoaster pentaradiatus Discoaster surculus Discoaster tamalis Discoaster triradiatus Discoaster variabilis Discophaera tubifer Florisphaera profunda small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra ampla Reticulofenestra minuta Reticulofenestra minutula Rhabdosphaera clavigera Syracosphaera pulchra Scyphosphaera sp. Umbilicosphaera sibogae Late Pliocene CN12a H-3, V G C C. F R C A C. C F F F.. V C C C C C F F F C C C A C C A. A H-4, V G C C F F F C A C. C F F F.. A C C F C F C C C C C C A C C A F A H-4, V M C C F F F C F C. C F F F.. A C C C C F C F F F C C A C C A F C H-4, A M F C... C C C. F F F F.. A C F C C. C. C F C C A C F A F C H-5, V G C C.. F C C C. C F F F. F A C F C C F C F F F F C A A C C. A H-5, V G C C... C C A. C F F F.. A C C C C. C F C F F A A C C C F A H-5, V M C C F F F C C C F C C F F.. A A C C C F F F C F C F A C C C F A H-6, V G C C F F. C C F F C F C F.. A C C C C. F F C F F C C C C C. C H-6, V G C C F. F C C A. C F F F.. A A C F C. C F C F C C A C C C F C H-7, V G C C C.. C C C. C C C F.. A A C C C C F C C C F F A C C C F A H-CC V G C C F.. C C F. F F F F. F. C C F C. F F C F F C A C C. F C H-1, V G C C F F. C C C F F C F F.. A C C C C F F. C F C A A A C C C A H-2, V M C C F F. C A C F C F C F.. V C C C C F C C C C C C A F C A C C H-3, A M C C... F C C F C F C F.. V C C C C. C F C C C F A C C A C A H-4, A M C C F.. F C C. F F C F.. C C C F C F C. C C F F A C C C F A H-4, V G C C C. F F C C. C C C F.. A A F C C. C F C F F F A C C. F A H-5, V G C C F C. C C C. C C C F.. A C C C A. F. C F C C A C C A C A H-5, V G C C C F. C C F. C F F F F F A C C C F. F F F C A F A F C C F C H-6, V G C C F F F C C C. C C C F.. V C C A C. F F C C A F C C C F. A H-6, V G C C F F. C C C. C F C... V C F A C F. F C F A F C C C F F A H-7, V G C C F F. C C c. C F C. F. A C C C C.. F F C A C A C C C C A H-CC V G C C F F R C C C F C C C F F. V C F C C. F F C C A F A C C C C A H-1, V G C C F F F C C C, C C C F F F V A C C C, F F C C A F C F C C F A H-1, V G C C F F. C C C. C C C F F. A C F C C. F F C F F F C F C C C A H-2, V G C C... C C C F C F F. F. V C F C C. F F C F C F C F C C F A H-2, V G C C. F. C C C. C C C. F. A C F C C F F F C C C C C F C C. A 28

42 Table 3.9. Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster challengeri Discoaster pentaradiatus Discoaster surculus Discoaster tamalis Discoaster triradiatus Discoaster variabilis Discophaera tubifer Florisphaera profunda small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera multipora Pontosphaera plana Pseudoemiliania lacunosa Reticulofenestra ampla Reticulofenestra minuta Reticulofenestra minutula R. pseudoumbilicus Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbilicosphaera sibogae Late Pliocene Early Pliocene CN12a CN H-3, V G C C F F R C C C F C F C F F. A A F C C... C. C C C A C. C. C F C H-3, V G C C F F. C C C C C C F F F. A C F C C. F F C. C C C A F. C. C F C H-3, A G C C F F F C C C F F F F F F F F A F C C. F F C. F F F C F. C. C. C H-4, V G C F... C C C F C F F F F F A C F F C. F F C. F C C A C. C. C F A H-4, A G C C F F. C C C F C C C F F F A C F F C. F F C. F F F A C. C. C C C H-5, A G C C F F. C C C F F F C F F F A A F C C.. F C. F F F C F. C. C. C H-5, A G C C F F. C C C F F F F F F. A C F C C. F F C. C C C A C. C. C F C H-5, C G C C C.. F F C F F F F F F. A C F C C. F. F. C F F A F. F. F F C H-6, C G C C F F R C C C F C F F F F. A C. C C. F F C. F A C A F. C. C F A H-6, V G C C... F F C. F C F F F. A C F C C. F F C. C F C A F. C. C F A H-7, C M F C F F. F F F. F F F. F. A C F F C. F. C. F C F A C. C. C F C H-CC V G C C C. R F C F. C F F. F F F C C C C F C F C F C F F C F. C. C F C H-1, A G C C C. F F C C F F F C. F. F C F C C. C F C. C C F A F. C. C F A H-2, V G C C C F. F A C F F F F F F. C A F A C. F F C F F C F A C. C F C F A H-2, V G C C C F R F A C F C F F F. F A A F C C F F F C F C C C A C. C A F F A H-3, A G C C F F F F A C. C F C F. F A A C C C. F C C F C C F A C. C F C F A H-4, V G C C C F. F C C F F F F F F. C C F C C F F. C F C F. A C. C C C. A H-4, V G C C F F. F C C F C F F F.. C A F C C... C F C A. A C. C A F F A H-4, V G C C C.. F A A F C C F F F, A A F C C F C, C F C F, A F, C C C F A H-5, V G C C F.. F C C. C C F F F F C C F C C F F F C F C F. A C. C A C F A H-5, V G C C C F. F C C F C F F F F. A A F C C... C F C F. A F. C A C F A H-5, V G F C F. F F C C C F F F F F. C C F C C. F. C F F C. A F. C A C F A H-6,63-65 V G C C... F C C F C F F... C C F C C. F C C F C F. A F. C A C. C H-7, A G F C F. R F C F F C F F F.. C A F C C. F. F. F C. A C. C A C F C H-CC A G F F... F C F F F F R. F F A C. F F. F F F F. F. A F. C A F. C 29

43 Table Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster challengeri Discoaster pentaradiatus Discoaster surculus Discoaster tamalis Discoaster triradiatus Discoaster variabilis Discophaera tubifer Florisphaera profunda small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera multipora Pontosphaera plana P. lacunosa Reticulofenestra ampla Reticulofenestra minuta Reticulofenestra minutula R. pseudoumbilicus Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae Early Pliocene CN H-1, V G F C. F. F C C C F F F F F. A A F C C... C F C F. C A. C A C F. C H-1, V G C F.. R F A C C F F F F F. A A F C C... C F C F. C A. C A C F. C H-2, A G C C... C A C C F F F F F. A A F C C... C F C C. A A. C A C F. C H-2, V G C C F F R F A C F F F F F F F A A F C F. F. C. C C. A A. C A C F. C H-2, V G C F F.. F C C F C F F F F. F C F C C. F F C F F F. A A R C A C F. C H-3, V G C C.. R F C F. C C F F.. A C F C C. F. F F F F. A A F C A C F. C H-3, V G C F F.. C C C F C C F F. F A C F C C. C. C F C F. A A F C A C F. A H-3, V G F F. F R C C C. F C F F.. A C F C F. F. C F F F. A A R C A C F. C H-4, F M C.. F... F A C. F F F. C.. F A H-4, V G C F F.. F C C C C F F F F. A A. C C. F. F F F F. A A F C A C F. A H-5, V G C F F. R F C C C C C F F F. A A F C C. F.. F F F. A A F F A F F. C H-5, V G F C F F. F C C F F F F F F. C C F C C. F. C F C F. A A F C A C F. C H-6, V G C F... F C C F C F F F.. C C F C F. F F F F C F. A A F C A C F. A H-6, V G C C F.. F C C F C F F F F. A A F C C F F. F F F F. A A F F A F F. A H-6, V G C C... F C C F C F F F F. C C F C C F.. C F F R. A A F F A F F. C H-7, V M F C F.. F C C F F F.... C C F C C... C F C R. A A F F A. F. C H-CC A M F C... F F F. F F.... A C. C F. F. F. F.. A A F F A H-1, V G C F.. F. A C F C F. F F. A C. C C F C F F F C.. A A F C A F.. A H-1, V G C C... F C F F C F F F.. A C C C C.. F C F C.. A A F C A C F. F H-1, V M F F. C. F C F F C F F. F. C C C C C.. C F F F.. A A F C A C H-2, A G F F... F C C. C F. F F F A C. C C.. F F F F.. A A F F A C.. A H-2, V G C F... F C C F F F F F F. A C. C C. C. C F F.. A A C C A F.. A H-2, V G C C. F F F C C C C C. F.. A C F C C. F. C F C.. A A C C A A.. A H-3, B H-4, C M.. F... F C F. F C F F F C F F. F H-5, F M R... R C F.. C

44 Table Calcareous nannofossil range chart of Hole 1396C. Age Nannof ossils zones or subzone Hole 1396C Depth (mbsf) Sample (coresection- interval in cm Abundance Preservation B. bige;owii Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Dictyococcites productus Discoaster asymmetricus Discoaster brouweri Discoaster challengeri Discoaster pentaradiatus Discoaster surculus Discoaster tamalis Discoaster triradiatus Discoaster variabilis Discophaera tubifer Florisphaera profunda small Gephyrocapsa Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Oolithus antillarum Oolithus fragilis Pontosphaera discopora Pontosphaera multipora Pontosphaera plana P. lacunosa Reticulofenestra ampla Reticulofenestra minuta Reticulofenestra minutula R. pseudoumbilicus Rhabdosphaera clavigera S. abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbellosphaera tenius Umbilicosphaera sibogae Early Pliocene CN H-6, A M. C F. F R F F F F F F. F.. C C. F F... F F F.. A F F F C F.. C H-1, V G. C C. F. F C C F C F F F F. A A F C C. C F C F F.. A A F C A F F. C H-1, V G. C.. F. F F C F C F. F F. A C. C C. C F C F F.. A A F C A C F. C H-1, V G. C C C.. F C C. F C. F F F A C C C C. F C F F... A A C C A C.. A H-2, V G. C C F F F F C C. C F. F F. A C F C C. F F C C C.. A A C C A C.. A H-2, V G. C F F.. F F C F F F. F F. A C. A F. F F C F C.. A A F C A C F. C H-2, V G. C C C F.. C C F C F. F F. A C. C F... C F F.. A C C C A C C H-3, V G. C C C. R. C C F C F. F.. A C C C C.. F C F... A A C C A F F. A H-4, V G. C F.. F. C C C C F. F.. A C. C C... C F F.. A A C C A F F H-4, V G. C F C F.. C C C C C F F F. R C. C C. F F C F C.. A A C. A. F. C H-5, V G. C F. F.. C F F C C. F F. A C. C C F.. C F... A A C C A C F. A H-5, V M. C F. F.. C C F C F. C F. F C. C C. F F C F F.. A C C C A C F. A H-5, V G. C F F F.. C C C C C. F F. A C F C C... C F C.. A C C C A C.. A H-6, V G. C C. F.. C C F C F. F.. A C F C C. F F C F F.. A A C. A. F. A H-6, V G. C C F F.. C C C C C. F.. A C F C C F.. C F C.. A A C C A C F. A H-7, V G. C C F F.. C C F C F. F.. A C F C C. F F C F C.. A A F C A C F. A H-CC V G R F C F F R. F C F C F. F.. A C. C C.. F C F C.. A A C C A C F. A H-1, V G. C C F F.. C C C C C. F.. A C C C C... C F C.. A A C C A C F H-1, V G.. C F F.. C C F C C. F.. A. F C C. C F C F F.. A A C F A A C. A H-2, V G. C.. F R. C C F C C. F.. A. F C C. F F C F C.. A A A F A C C. C H-2, V G. C F F F R. C C F C F. F.. V.. C C... C F F.. A A F F A F F. A H-3, 25-27, V G. C C F F.. C C F C F. F.. A.. C C.. F F F... A C F F A F F. C H-3, V G. C C F F... C C C F.... A. F C C... C F F.. A C F F A F.. C H-4, F G.. F F C F.. C H-4, V G. C C F F F. C C C C C. F F. A. F F F... C F F.. A C C. A F C. C H-4, V G. C C F F.. C F F F F. F F. A.. C F... C F C.. A C C F A F.. C 31

45 Table Calcareous nannofossil range chart of Hole 1396C. Age Early Pliocene Nannof ossils zones or subzone CN 11 Hole 1396C Depth (mbsf) Sample (coresectioninterval in cm Abundance Preservation Calcidiscus leptoporus Calcidiscus macintyrei Calciosolenia murrayi Ceratolithus rugosus Coccolithus pelagicus Discoaster asymmetricus Discoaster brouweri Discoaster challengeri Discoaster pentaradiatus Discoaster surculus H-5, G V C F F F.. C C C C.. A C C C F C F. A A C. A C. A H-5, G V C.... C C C C C F F A F... F F C A A C. A.. C H-6, G V C F F C F C C C C C F F A. C C.. F C A C C A A C C C H-6, G V C F.. R C F C C C F F A. C C. C F F A A C F A C C A H-6, G V C F... C F C C F F C A F C C. C F C A A C. A F F C H-7, G V. F... C F C C F F C A F C F. C F C A A C C A.. C H-7, G V C C.. R C F C C F F C A. C C.. F F A A C. A C H-CC G V C F.. R C C. C C F. A F C C.. F F A A C. A.. C Discoaster triradiatus Discoaster variabilis Florisphaera profunda Hayaster preplexus Helicosphaera carteri Helicosphaera kamptneri Helicosphaera sellii Pontosphaera discopora Pontosphaera multipora Pontosphaera plana Reticulofenestra minuta Reticulofenestra minutula R. pseudoumbilicus Rhabdosphaera clavigera Sphenolithus abies/neoabies Syracosphaera pulchra Scyphosphaera sp. Umbilicosphaera sibogae 32

46 Fig Summary of the nannofossil biostratiraphy of Hole 1396C. First occurrence Last occurrence 33

47 3.3. Experiments on Diagenesis During the expedition, thirty-six samples throughout Holes 1396A and C were used for water content determinations that required heating each sample in a non-sealed oven at 105 C for 24 hours. Scanning electron microscope (SEM) observations were carried out during the summer at KAUST, Saudi Arabia to evaluate the overall preservation of nannofossils in these samples. The SEM, a FEG Quanta 200, is a high resolution machine that is ideal for observations of nanno-size objects. The preparation technique of the SEM was previously described in chapter two, section and Severe diagenesis was observed on nannofossils in all samples. Although carbonate diagenesis includes both secondary overgrowth and dissolution, all thirty-six samples showed considerably more overgrowth than dissolution. Most of the placoliths, including Gephyrocapsa, Reticulofenestra, and Calcidiscus spp, still have their shields intact. Dissolution in these species was apparently common to few, whereas heavy overgrowth is present in every sample. Small Gephyrocapsa that are readily susceptible to dissolution, are common and overgrown in all samples. Discoaster species have severe overgrowths and minimal dissolution in the center area and part of the arms. Similarly, Helicosphaera, a genus that are quite dominant throughout this sequence, are heavily overgrown, and few were found with even slight etching. To understand the reason of this abnormal carbonate diagenesis, and to evaluate the original nature preservation of the samples, a comparison with unprocessed, non-heated samples was carried out (Figs. 3.4; 3.5 and 3.6). A comparison with non-heated samples was carried out using the SEM of the Physics Department at Florida State University. This comparison shows that the nannofossils of Hole 1396C are generally well-preserved. Although the resolution of the FSU SEM is less than the Saudi Arabian machine, placoliths in the original samples are well-preserved, whereas little sign of diagenesis was observed in discoasters. Helicosphaera sp., and Calcidiscus sp., are also abundant and well-preserved. It is evident that the overgrowth features seen in the samples used for water content determinations were not the product of biological calcification; hence, heating the samples at 105 C at room pressure caused this "artificial" abnormal diagenesis. 34

48 A B C D E F Fig Comparison of scanning electron micrographs between heated samples (left) and non-heated, original sample (right). A Helicosphaera kamptneri. (Sample 6H-6, cm). B. Helicosphaera kamptneri in original Sample (14H-1, 90-92cm). C. Discoaster surculus (11H-1, 85-87cm). D. Discoaster surculus original Sample (14H-1, 90-92cm). E. Discoaster assymetricus (14H-6, cm). F. Discoaster assymetricus in original Sample (14H-1,90-92 cm). 35

49 A B C D E F Fig Comparison of scanning electron micrographs between heated samples (left) and non-heated, original sample (right). A. Discoaster pentaradiatus (Sample 7H-6, 73-75cm). B. Discoaster pentaradiatus in original Sample (14H-1, 90-92cm). C. Discoaster surculus (10H-5, 76-78cm). D. Discoaster surculus in original Sample (14H-1, 90-92cm). E. Calcidiscus leptoporus (5H-1, 47-49cm). F. Calcidiscus leptoporus in original Samples (10H-6, cm). 36

50 A B C D E F Fig Comparison of scanning electron micrographs between heated samples (left) and non-heated, original sample (right). A. Discoaster assymetricus? (6H-6, cm). B. Discoaster assymetricus? in original Sample (14H-1, cm). C. Helicosphaera kamptneri (13H-5, cm). D. Helicosphaera kamptneri in original Sample (14H-1, cm). E. Reticulofenestra sp., (10H-5, cm). F. Reticulofenestra sp., in original Sample (14H-1, 90-92cm). 37

51 CHAPTER FOUR DISCUSSION 4.1. Nannofossil Correlation Nannofossil events in Hole 1396C correlate well with Hole 1000A in the Caribbean Sea. A summary of nannofossil correlations is found in Fig Kameo and Bralower (2000) used the LO of Sphenolithus spp. as an event included within the subzone Discoaster tamalis (CN12a) following Bukry (1991) who subdivided Subzone CN12a into three subzones at Site 806B in the Pacific Ocean: Subzone CN12aA Discoaster tamalis (Subzone Sphenolithus spp. defined by the LO of R. pseudoumbilica to LO of Sphenolithus spp.) Subzone CN12aB Discoaster tamalis (Subzone Discoaster varabilis, defined by the LO of Sphenolithus spp., to the LO. Of Discoaster variabilis) Subzone CN12aC Discoaster tamalis (No D. varabilis, defined by the LO of D. variabilis to the LO of D. tamalis). Kameo and Bralower (2000) used only the LO of Sphenolithus spp as an event (CN12aA) without recording the other two subdivions (CN12aB and CN12aC). This division of the subzone CN12a, however, was not followed in this study owing to the inability to distinguish them. In addition, these events, proposed by Bukry (1991), are neither calibrated by astronomical ages or by magnetic polarity. According to Okada and Bukry (1980), the LO of both Sphenolithus spp., and R. pseudoumbilica defines the top of the CN11 zone. However, many DSDP, ODP and IODP low-latitude studies have found the LO of Sphenolithus spp., well above the LO R. pseudoumbilica, (Kameo and Bralower, 2000; Manivit, 1989; Rio et al., 1990b; and others) thereby supporting the hypothesis of Hay (1972) that no two events occur at the same time. Perch-Nielsen (1985) suggested using Sphenolithus spp. as the primary marker when the R. pseudoumbilica is rare or absent in low-latitude regions. Hence, the LO of Sphenolithus spp. in this study was included within the Zone CN11, following Okada and Bukry (1980), and designated as the marker defining the top of the zone. 38

52 The Zone CN11 was not subdivided into subzones based on the acme of Discoaster assymetricus due to the lack any major changes in its abundance throughout the drilled sequence. Hole 1396C was abandoned as planned in advance, hence before the Miocene-Pliocene boundary was penetrated. The base of Zone CN11, marked by the LO of Amaurolithus primus and/or A. tricorniculatus, therefore, was not completely reached and its subzones could not be distinguished Age-Depth Plot Age-depth plot based on nannofossil ages provide sedimentation rates for Hole 1396C (Fig 4.2). Nannofossil events (Table 3.1) show low sedimentation rates in the Pleistocene (between 0.60 mbsf to 35 mbsf) and high sedimentation rates during the Pliocene (40 mbsf to 140 mbsf, to the base of the hole). To evaluate the accuracy and precision of these ages, they were correlated with magnetic polarity ages (Table 4.1; Expedition 340 Scientists, 2013; Fig 4.3). The two ages sets show a drastic change in sedimentation rates suggesting reliable nannofossil age-dates for Hole 1396C. This pattern of sedimentation rates by nannofossils was compared with that in Hole 1000A (Fig 4.4) which shows a similar trend. The similar sedimentation rates at both Sites 1396 and 1000 are considered to be regional events attributed to the closing of the Central American seaway during the Pliocene (Shipboard Scientific Party, 1997). Although the comparison between nannofossil and magnetic ages of Hole 1396C (Fig. 4.3) shows a similar sedimentation rate trend, a discrepancy between the two ages occurs in the Helicosphaera sellii Zone (27.92 to mbsf). As noted previously, Helicosphaera sellii was only recorded in four samples (Table.3.5) showing few to rare abundance. This marker species is sporadic throughout the sequence. Hence, the LO of H. sellii may not precisely reflect a reliable event as it is inconsistent agreement the magnetic ages in the age-depth plot (Fig. 4.3) Abnormal Diagenesis Von Gumbel (1868) coined the term "diagenesis" referring to any non-metamorphic physical and chemical post-depositional alterations to the sediment. Two phases of diagenesis, early and late, are observed in calcareous marine microfossils from both deep-sea and outcrop sequences (Burns, 1975; Schlanger and Douglas, 1974; Schlanger et al., 1973; Roth, 1973; Wise, 39

53 1973; Weaver and Wise, 1973). Early diagenesis involves the alteration of the sediment at the sediment-water interface, when neither high temperature nor uplift above sea level is encountered (Berner, 1980). Late diagenesis, on the other hand, begins in a basin with considerably progressive burial between 600 to 1000 meters that induces compaction and recrystallization to lithify the sediment into a chalk or limestone (Wise, 1977). Early diagenesis in both carbonate and siliceous materials received considerable attention and has been investigated in much detail by the scanning electron microscope (SEM) to infer diagenetic history (Matter et al., 1975; Weaver and Wise, 1973; Wise and Kelts, 1972; Wise, 1977). Late diagenesis, however, has only been observed in deep-sea sequences (Roth, 1973; Schlanger and Douglas, 1974); thus, more investigations that simulate the progression of diagenesis are needed. The first experiment that simulated the development of late diagenesis in the deep sea was conducted by Adelseck et al. (1973) in which well-preserved nannofossil assemblages from the upper Pliocene were exposed for one month to different high temperatures and pressures (up to 300 C and 3 kb). Compared with untreated samples via the scanning electron microscope (SEM), Adelseck et al. (1973) found that minor morphological changes in nannofossils occurred at 200 C-1 kb, whereas major alterations (e.g., dissolution and/or overgrowth) began between 200 C to 300 C at 1 kb with little effect observed with increasing pressure. These major changes revealed minor etching but severe overgrowth on large placoliths and discoasters that were primarily caused by exposure to high temperature. Although our results from the water-content determination experiment show a trend similar to the overgrowth observed by Adelseck et al. (1973), the heavily overgrown nannofossils in our study indicate that a temperature at 105 C at room pressure for only 24 hours was quite sufficient to cause major alterations. This finding requires further investigation to determine the source of overgrowths and to develop a diagenetic model to elucidate the progression of diagenesis in nannofossils subject to tectonics activities and/or expose to high temperature and pressure. 40

54 First occurrence Last occurrence Fig Correlation of calcareous events of Hole 1396C with Hole 1000A. Biostratigraphic summary of Hole 1000A is from Kameo and Bralower,

55 Table 4.1. Magnetic ages constructed during Expedition 340 (Expedition 340 Scientist, 2013). Magnetic ages (Ma; Expedition 340 Scientists, 2013) Depth (mbsf) Reference Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) Cande and Kent, 1995) 42

56 Table 4.2. Nannofossil ages for Hole 1000A used by Kameo and Bralower (2000). Event Zone Age Depth B Emiliania huxleyi CN T Pseudoemiliania lacunosa CN14b T Reticulofenestra asanoi B Gephyrocapsa parallela B Reticulofenestra asanoi T Gephyrocapsa spp. (large) T Helicosphaera sellii B Gephyrocapsa spp. (large) B Gephyrocapsa oceanica T Calcidiscus macintyrei B Gephyrocapsa caribbeanica CN13b T Discoaster brouweri CN13a T Dicoaster pentaradiatus CN12d T Discoaster surculus CN12c T Discoaster tamalis CN12b T Reticulofenestra ampla T Reticulofenestra minutula T Sphenolithus spp T Reticulofenestra pseudoumbilia CN12a

57 B Emiliania huxleyi B G. parallela T Pseudoemiliania lacunosa T H. sellii T R. asanoi B R. asanoi B G. caribbeanica Age-Depth plot B G. oceanica T C. macintyeri T D. brouweri T D. pentaradiatus T D. surculus T D. tamalis T R. ampla T Sphenolithus spp 3.82 T R. pseudoumbilica Nannofossils (this study) Fig Age-depth plot by nannofossils for Hole 1396C. B refers to Base or (FO), whereas T refers to Top or (LO). 44

58 Magnetic Nannofossils (this study) Fig Integration of nannoffossil and magnetic age-model for Hole 1396C. 45

59 Nannofossils (this study) Nannofossils 1000 (Kameo and Bralower, 2000) Magnetic (EXP 340, 2012) Fig Comparison between nannofossil and magnetic ages for Hole 1396C and Hole 1000A (nannofossil ages). 46

60 CHAPTER FIVE CONCLUSION Hole 1396C from the Expedition 340 of the Integrated Ocean Drilling Program (IODP), provides a lower Pliocene to Pleistocene record of calcareous nannofossil assemblages (CN11 to CN15). The calcareous nannofossils are generally common to abundant and exhibit moderate to good preservation. In the upper Pleistocene, nannofossils are common and exhibit moderate preservation with an increase in fragmentation. From the lower Pleistocene to Pliocene (base of the hole) nannofossils are abundant to very abundant with good to excellent preservation. The zonations of Gartner (1977) for the Pleistocene and Okada and Bukry (1980) for the Pliocene were applied and worked well throughout the sequence to improve the biostratigraphic record. In the Pleistocene, the Small Gephyrocapsa Zone was not consistently recognized because the small sizes of the specimens make them are readily susceptible to dissolution. Thus, the Pseudoemiliania lacunosa Zone was expanded to include this interval in the study. The Reticulofenestra pseudoumbilica Zone was delineated in this study without subzones (i.e., without Subzones CN11a, (Discoaster asymmetricus) and CN11b (Sphenolithus neoabies) because no major change of Discoaster asymmetricus abundance was observed. This is probably because Zone CN11 was not recovered completely as the site was abandoned after recovering only 140 meters of hemiplagic sediment. Nannofossils ages compiled from the recent update of Backman et al. (2012) were used to construct an age-depth plot to infer the sedimentation pattern for the last 5 m.y. in the eastern Caribbean Sea. Sedimentation rates inferred by the nannofossil biostratigraphy suggest low sedimentation rates in the Pleistocene and high sedimentation rates in the Pliocene. Magnetic polarity ages, conducted during the expedition, agree with the sedimentation patterns and suggest that the nannofossils age-dates for Hole 1396C are reliable. Nannofossils at both Site 1396 and ODP Site 1000 to the west correlate quite well and show the same sedimentation pattern with in the central Caribbean Sea. It is evident that regional high sedimentation rates during the Pliocene in the Caribbean Sea were caused by the closing of the Central American seaway. Selected samples from Holes 1396A and C were heated abroad ship at 105 C in a nonsealed oven at room pressure for 24 hours to determine the water content of each sample. 47

61 Observations of these samples via the scanning electron microscope (SEM) show severe overgrowths and etching of the nannofossils. By comparing untreated samples from the same hole, the temperature of 105 C is responsible for this heavy overgrowth and a more detailed investigation is now needed to determine the source of the overgrowth material and build a diagenetic model for such cases with high temperatures and/or pressures. 48

62 APPENDX A ALPHABETICAL LIST OF CALCAREOUS NANNOFOSSILS CONSIDERED IN THIS THESIS (GENERA IN ALPHABETICAL ORDER) Braarudosphaera bigelowii (Gran and Braarud, 1935) Deflandre (1947) Calcidiscus leptoporus (Murray and Blackman, 1898) Loeblich and Tappan (1978) Calcidiscus macintyrei (Bukry and Bramlette, 1969) Loeblich and Tappan (1978) Calciosolenia murrayi (Gran in Murray and Hjort, 1912) Ceratolithus cristatus (Kamptner, 1950) Ceratolithus rugosus Bukry and Bramlette (1968) Coccolithus pelagicus (Wallich, 1877) Schiller (1930) Dictyococcites productus (Kamptner, 963) Backman (1980) Discoaster asymmetricus (Gartner, 1969) Discoaster brouweri (Tan, 1927 emend. Bramlette and Riedel, 1954) Discoaster challengeri (Bramlette and Riedel, 1954) Discoaster pentaradiatus (Tan, 1927) emend. Bramlette and Riedel (1954) Discoaster surculus (Martini and Bramlette, 1963) Discoaster tamalis (Kamptner, 1967) Discoaster triradiatus Tan (1927) Discoaster variabilis (Martini and Bramlette, 1963) Emiliania huxleyi (Lohmann, 1902) Hay and Mohler in Hay et al., 1967 Florisphaera profunda (Okada and Honjo, 1973) Gephyrocapsa (small) Matusoka and Okada, 1989 Gephyrocapsa caribbeanica (Boudreaux and Hay in Hay et al., 1967) Gephyrocapsa oceanica (Kamptner, 1943) Gephyrocapsa parallela (Hay and Beaudry, 1973) 49

63 Hayaster perplexus (Bramlette and Riedel, 1954) Bukry (1973) Helicosphaera carteri (Wallich, 1877) Kamptner (1954) Helicosphaera kamptneri (Hay and Mohler in Hay et al., 1967) Helicosphaera sellii (Bukry and Bramlette, 1969) Oolithotus antillarum (Cohen, 1964) Reinhardt in Cohen and Reinhardt (1968) Oolithotus fragilis (Lohmann, 1912) Martini and Mueller (1972) Pontosphaera discopora (Schiller, 1925) Pontosphaera multipora (Kamptner, 1948) Roth (1970) Pontosphaera plana (Bramlette and Sullivan, 1961) Haq (1971) Pontosphaera pulchra (Deflandre in Deflandre and Fert, 1954) Romein (1979) Pseudoemiliania lacunosa (Kamptner, 1963) Gartner (1969) Reticulofenestra ampla (Sato et al., 1991) Reticulofenestra asanoi (Sato and Takayama, 1992) Reticulofenestra minuta (Roth, 1970) Reticulofenestra minutula (Gartner, 1967) Haq and Berggren, 1978 Reticulofenestra pseudoumbilica (Gartner, 1967) Gartner (1969) Rhabdosphaera clavigera (Murray and Blackman, 1898) Schyphosphaera sp. Lohman (1902) Sphenolithus abies (Deflandre in Deflandre and Fert, 1954) Sphenolithus neoabies (Bukry and Bramlette, 1969) Syracosphaera pulchra (Lohmann, 1902) Umbellosphaera tenuis Kamptner (1937) Paasche in Markali and Paasche (1955) Umbilicosphaera sibogae (Weber-van Bosse, 1901) Gaarder (1970) 50

64 APPENDIX B PLATES Fig. B.1. (1) Hayaster preplexus, Sample 7H-3, cm. (2, 9-10). Ceratolithus rugosus Sample 9H-6, (3). Braarudosphaera bigelowi Sample 7H-3, cm. (4). Coccolithus pelagicus Sample 5H-3, cm. (5-6). Helicosphaera sellii Sample 6H-6, cm. (7). Pontosphera discopora Sample 9H-2, cm. (8). Pontosphaera plana Sample 6H-4, cm. (11). Calcidiscus leptoporus Sample 2H-3, cm. (12). Rhabdosphaera claviger Sample 7H-2, cm. 51

65 Fig. B.2. (1) Pontosphera multipora Sample 10H-5, cm. (2). Spehnolithus sp. Sample 11H-5, cm. (3). Reticulofenestra pseudoumbilica Sample 15H-6, cm. (4). Pseudoemiliania lacunosa Sample 7H-4, cm. (5,11). (cross nicoles and polarized light) Reticulofenestra ampla Sample 8H-1, cm. 6. Scyphosphaera sp. Sample 10H-2, (7-8). (polarized and cross nicoles) Reticulofenestra asanoi Sample 3H-2, (9). Gephyrocapsa oceanica Sample 2H-5, cm. (10). Gephyrocapsa caribbeanica Sample 3H-3, cm. 52

66 Fig. B.3. (1). Discoaster challengeri Sample 9H-CC. (2). Discoaster pentaradiatus Sample 9H-2, cm. (3). Discoaster surculus Sample 9H-CC. (4). Discoaster tamalis Sample 9H-6, cm. (5-6). Discoaster brouweri Sample 7H-3, cm. (7). Discoaster assymtericus Sample 9H-CC. (8-9). Calcidiscus macintyrei Sample 6H-6, cm. (10-11). Oolithus fragilis Sample 7H-4, cm. (12). Florisphaera profunda Sample 7H-2, cm. 53