Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 165. Caribbean ocean history and the K T boundary event

165_map......Page 1
Table 1. Location and water depth of the sites studied.......Page 2
RETURN TO CHAPTER 1......Page 0
Table 2. Ages of calcareous nannofossil events.......Page 8
STRATIGRAPHIC SIGNIFICANCE OF RETICULOFENESTRA COCCOLITHS......Page 13
ACKNOWLEDGMENTS......Page 14
REFERENCES......Page 15
Figure 2. Stratigraphic positions of additional nannofossil datums in Hole 998A. Zonal markers ar.........Page 3
Figure 3. Stratigraphic positions of additional nannofossil datums in Hole 999A. Zonal markers ar.........Page 4
Figure 4. Stratigraphic positions of additional nannofossil datums in Hole 1000A. Zonal markers a.........Page 5
Figure 5. Size distributions of Reticulofenestra specimens at Site 998. Abundance of individual s.........Page 6
Figure 6. Size distributions of Reticulofenestra specimens at Site 999. Abundance of individual s.........Page 7
Table 3. Stratigraphic position of datums in Hole 998A.......Page 9
Table 4. Stratigraphic position of datums in Hole 999A.......Page 10
Table 5. Stratigraphic position of datums in Hole 1000A.......Page 11
Appendix A. Twenty-three genera and 112 species recognized in this investigation of the core samples are listed below.......Page 16
SITE DESCRIPTION......Page 17
Figure 1. Bathymetric map of the western Colombian Basin including the locations of Site 999 and .........Page 18
SEDIMENT ACCUMULATION RATES......Page 20
Figure 3. The age/depth relationship for planktonic foraminifer datums in Hole 999A. Filled circl.........Page 21
TECTONIC AND PALEOCEANOGRAPHIC IMPLICATIONS......Page 27
TAXONOMIC NOTES......Page 28
REFERENCES......Page 35
Figure 2. Planktonic foraminifer and nannofossil biozones are shown with the geopolarity time sca.........Page 19
Table 3. Site 999 and Site 925 datum ages compared.......Page 23
Table 2. Planktonic foraminifer datums used to construct age/depth plot.......Page 22
Table 5. Datums used to construct age model for Hole 999A.......Page 24
Appendix A. Species' ranges, Hole 999A.......Page 38
Appendix A (continued). Pleistocene-late Miocene.......Page 39
Appendix A (continued). Pleistocene-late Miocene.......Page 40
Appendix A (continued). Pleistocene-late Miocene.......Page 41
Appendix A (continued). Pleistocene-late Miocene.......Page 42
Appendix A (continued). Pleistocene-late Miocene.......Page 43
Appendix A (continued). Pleistocene-late Miocene.......Page 44
Appendix A (continued). Late Miocene-early Miocene.......Page 45
Appendix A (continued). Late Miocene-early Miocene.......Page 46
Appendix A (continued). Late Miocene-early Miocene.......Page 47
Appendix A (continued). Late Miocene-early Miocene.......Page 48
Appendix A (continued). Early Miocene......Page 49
Appendix A (continued). Early Miocene......Page 50
Appendix B. Sample Ages, Hole 999A.......Page 51
Plate 1. All specimens are magnified 70X. 1. Truncorotalia truncatulinoides (Sample 165-999A-5H-C.........Page 52
Plate 2. All specimens are magnified 70X. 1. Fohsella fohsi (Sample 165-999A-33X-6, 42–44 cm), um.........Page 54
RADIOLARIAN PRESERVATION......Page 55
Figure 1. Location of Leg 165 sites examined for Paleogene radiolarians. Contours are in meters b.........Page 56
SITE DESCRIPTIONS......Page 58
REFERENCES......Page 68
APPENDIX 1......Page 70
Figure 2. Correlation chart of Paleogene zonal schemes for foraminifers, calcareous nannofossils,.........Page 57
Table 1. Range chart for stratigraphically important radiolarian species, Hole 998A.......Page 59
Table 2. Range chart for stratigraphically important radiolarian species, Hole 998B.......Page 60
Table 2 (continued).......Page 61
Table 3. Range chart for stratigraphically important radiolarian species, Hole 999B.......Page 62
Table 3 (continued).......Page 63
Table 3 (continued).......Page 64
Table 3 (continued).......Page 65
Table 3 (continued).......Page 66
Table 4. Range chart for stratigraphically important radiolarian species, Hole 1001A.......Page 67
Plate 1. Scale bar for fig. 1 = 100 µm; scale bar for figs. 2-17 = 100 µm. Codes after sample des.........Page 74
Plate 2. Scale bar for fig. 12 = 100 µm; scale bar for figs. 1-11, 13-17 = 100 µm. Codes after sa.........Page 76
Plate 3. Scale bar for figs. 1-13 = 100 µm. Codes after sample description are slide description .........Page 78
INTRODUCTION......Page 80
Figure 1. Bathymetric map of Cariaco Basin (in meters) showing the location of ODP Site 1002 on t.........Page 81
RESULTS......Page 82
Figure 6. Comparison between the delta18O record of Hole 1002C and the standard SPECMAP composite rec.........Page 89
REFERENCES......Page 93
Figure 2. Simplified stratigraphic column for ODP Hole 1002C showing the subsurface distribution .........Page 83
Figure 3. Comparison of lithologies recovered at ODP Site 1002 and DSDP Site 147 at approximately.........Page 84
Table 2. Biostratigraphic datums recognized at Site 1002.......Page 87
Figure 5. Expanded detail of the delta18O record of G. ruber for MIS 1 to the top of MIS 6 in Hole 10.........Page 88
Figure 7. Comparison of filtered components of the Site 1002 and SPECMAP delta18O records correspondi.........Page 90
Figure 8. Age-depth function for Hole 1002C derived from the correlation of its delta18O record to th.........Page 91
Figure 9. Downhole variations (wt%) in measured calcium carbonate, total organic carbon (TOC), an.........Page 92
Table 1. Oxygen isotope data from ODP Hole 1002C.......Page 85
Table 1 (continued).......Page 86
BACKGROUND......Page 95
Figure 1. Map showing the major physiographic features of the Caribbean Sea and the location of t.........Page 96
Table 1. Feldspar size measurements of tephra fall layers, Site 998.......Page 97
Figure 5. Cumulative percentage of maximum feldspar size in all measured Miocene tephra fall laye.........Page 99
Table 2. Feldspar size measurements of tephra fall layers, Site 999.......Page 100
Table 3. Feldspar size measurements of tephra fall layers, Site 1000.......Page 102
Figure 12. Vectors of surface winds (1000 mb level) in the Caribbean area. Each barb on the wind .........Page 103
Figure 4. Variation in median size of the 20 largest feldspar crystals vs. thickness of tephra la.........Page 98
Figure 8. Cumulative percentage of maximum feldspar size in all measured Miocene tephra fall laye.........Page 101
Figure 13. Vectors of upper level winds (750 mb level, 11 km height) in the Caribbean area. Each .........Page 104
Figure 15. Reconstruction of the Caribbean area during the mid-Miocene showing the location of Le.........Page 105
Figure 17. Comparison of the maximum feldspar crystal size found in tephra fall layers vs. the nu.........Page 106
Figure 18. Comparison of the ash accumulation rate at Site 999 (right) with the dust grain-size r.........Page 107
INTRODUCTION......Page 108
Figure 1. Location map of sites drilled during Leg 165. Of the sites discussed here, Site 998 is .........Page 109
Figure 2. Absolute concentrations (in weight percent) of CaCO3 (light gray), terrigenous matter (.........Page 112
REFERENCES......Page 116
Figure 4. Terrigenous matter accumulation at Sites 998, 999, and 1001 vs. age, plotted with expan.........Page 113
Figure 6. Dispersed ash accumulation rate at Sites 998 (shaded circles), 999 (solid diamonds), an.........Page 114
Figure 7. Accumulation rate of dispersed ash (open circles) and accumulation of ash layers (solid.........Page 115
Table 1. Composition of Leg 165 sediments, based on shipboard XRF and coulometry.......Page 110
Table 1 (continued).......Page 111
RECENT QUATERNARY OF THE CARIACO BASIN......Page 118
Figure 5. Average duration of dark and light lower order cycles in each core of the virtual serie.........Page 124
Figure 8. Correlation between the sedimentation rate and the number of dark and light alternating.........Page 126
Figure 18. Carbonate concretion, 25 mm long, in a sample from the Querecual Formation, examined .........Page 131
Figure 19. (A) Siliceous and (B) carbonate concretions in an outcrop of the La Luna Formation nea.........Page 132
Figure 1. The Venezuelan areas included in this study. A. Cariaco Basin with bathymetric curves. .........Page 119
Figure 2. Simplified structural map of northern Venezuela showing the Transversale de Barquisimet.........Page 120
Figure 3. Schematic illustration of two orders of dark and light cycles occurring in a thin secti.........Page 121
Figure 4. Process for making the compaction and the sedimentation rates uniform through the Hole .........Page 122
Figure 6. Low-frequency cycles forming the Cariaco succession in Hole 1002C (after Sigurdsson, Le.........Page 125
Figure 10. Rounded sparitic concretion observed in a thin section from Sample 165-1002C-12H-1, 23.........Page 127
Figure 12. Schematic diagram of lamina bundles with their enlargements as appearing in thin secti.........Page 128
Figure 13. Discontinuous and irregular beige micritic layers (BML) in thin sections from the Quer.........Page 129
Figure 16. Light laminae of elementary cycles are deformed against calcitized fillings of forami.........Page 130
Table 1. Cariaco Basin, Hole 1002C.......Page 123
METHODS......Page 134
Figure 2. Zijderveld plots for Sample 165-1001A- 39R-2, 101-103 cm; 353.92 mbsf. A. Horizontal co.........Page 135
Table 1. Magnetostratigraphy and sedimentation rates of the K/T boundary interval.......Page 136
Figure 4. Inclination and magnetization data from Hole 1002C. The gray curve represents NRM data,.........Page 137
Figure 5. Rock-magnetic stratigraphy for Hole 1002C. The first column is the single-sample suscep.........Page 138
INTRODUCTION......Page 139
Figure 1. Location of Leg 165 drill sites (stars) and plate boundaries for the Caribbean plate (b.........Page 140
PALEOMAGNETIC DATA AND ANALYSIS......Page 142
Figure 6. Inclinations from basalt cores from Site 1001. Flow units (53A, 53B, etc.) are labeled .........Page 153
Figure 8. Variation of the precision parameter vs. latitude based on the geomagnetic SV model of .........Page 157
Figure 15. Change in latitude (paleolatitude minus the current latitude) from the paleomagnetic d.........Page 161
Figure 2. AF demagnetization results for Samples 165-998A- 40X-5, 134 cm, and 165-998B-10R-3, 90 .........Page 149
Figure 3. AF demagnetization results from Site 999 for sedimentary Samples 165-999B-11R-4, 89 cm .........Page 150
Figure 4. AF and thermal demagnetization results characteristic of some of the better sedimentary.........Page 151
Figure 5. AF and thermal demagnetization results characteristic of some of the better basalt samp.........Page 152
Figure 10. Site 999 paleolatitudes from discrete samples (open circles). Also shown are the unbia.........Page 158
Figure 12. The interval from Site 1001 in which the magnetostratigraphy could be established. The.........Page 159
Figure 14. Mean paleolatitudes from Sites 999 and 1001. The best-fit line through these (bold sol.........Page 160
Figure 16. Paleogeographic reconstruction of Pindell et al. (1988) with Leg 165 sites (stars) ove.........Page 163
Table 1. Flow unit divisions from this study compared with subdivisions used during Leg 165.......Page 143
Table 5. Split-core (archive half) paleomagnetic data from Hole 999A obtained during Leg 165.......Page 144
Table 9. Split-core (archive half) paleomagnetic data from Hole 1001A obtained during Leg 165.......Page 145
Table 12. Paleomagnetic results from discrete samples from Site 999.......Page 146
Table 15. Basalt split-core inclinations after AF demagnetization and after removing data from ne.........Page 147
Table 18. Inclinations from principal component analysis of discrete samples from ODP Site 1001.......Page 148
Table 19. Expected (observed) paleolatitudes and their relationship to the true paleolatitude.......Page 154
Table 19 (continued).......Page 155
Table 21. Mean paleolatitudes.......Page 156
INTRODUCTION......Page 164
Figure 1. Sonic velocity of discrete freshly recovered (water saturated) samples vs. burial for S.........Page 165
Figure 6. Density downhole logging data (solid line) compared to laboratory wet bulk densities of.........Page 170
Table 5. Occurrence of stylolites and microstylolites, Sites 806, 807, 999, and 1001.......Page 171
Figure 2. Examples of compaction curves. The resulting strain (e) is plotted vs. the uniaxial str.........Page 168
Figure 4. Compaction curves showing uniaxial stress (sigma) vs. porosity (phi) for all samples from Si.........Page 169
Figure 9. Compaction curves showing uniaxial stress (sigma) vs. porosity (phi) for samples from Site 1.........Page 172
Figure 12. Grain-size distribution of samples from Sites 999 and 1001 after compaction experiment.........Page 173
Figure 13. Sonic transit time (the inverse of sonic velocity) vs. porosity for samples from Sites.........Page 174
Table 2. Compaction experiments data, Sites 999 and 1001.......Page 166
Table 4. Specific surface and grain-size data, Leg 130 Site 807.......Page 167
Plate 1. Thin-section photomicrographs of samples from Site 999 subsequent to compaction experime.........Page 175
Plate 2. Thin-section photomicrographs of samples from Site 1001 subsequent to compaction experim.........Page 176
Plate 3. Wispy laminations in Paleocene clayey calcareous mixed sedimentary rock (Sample 165-999B.........Page 177
INTRODUCTION AND BACKGROUND......Page 178
Figure 2. View into the measurement chamber of the XRF core scanner of the Geosciences Department.........Page 180
Figure 5. The upper Paleocene interval drilled in Hole 999B. The section from 974 to 977 mbsf (lo.........Page 183
RESULTS......Page 185
Figure 9. The Paleocene/Eocene boundary as observed in Cores 165-1001A- 27R and 165-1001B-6R. The.........Page 188
CONCLUSIONS......Page 189
REFERENCES......Page 190
Figure 1 (continued). B. The Paleocene Caribbean (tectonic reconstruction from Pindell and Barret.........Page 179
Figure 3. Comparison of calibrated vs. uncalibrated (raw) FMS data from Site 999. Each trace repr.........Page 181
Figure 4. Late Paleocene thermal maximum (LPTM) as observed in a variety of downhole measurements.........Page 182
Figure 6. The composite upper Paleocene interval recovered at Site 1001 as a result of detailed c.........Page 184
Figure 7. Late Paleocene thermal maximum (LPTM) as observed in selected downhole measurements at .........Page 186
Figure 8. The Paleocene/Eocene boundary as observed in Cores 165-1001A- 27R and 165-1001B-6R. Sho.........Page 187
DATA SETS......Page 191
Figure 1. Location map for Sites 998, 1000, and 1001. Contour interval = 1000 m.......Page 192
Figure 7. Uncorrected sonic log and physical properties velocity measurements for Site 1001.......Page 194
Figure 9. Site 998 composite velocity profile containing edited sonic log and physical properties.........Page 195
Figure 15. Site 998 depth-TWT relationship with linear depth scale. Included are the impedance lo.........Page 198
Figure 17. Site 1001 depth-TWT relationship with linear depth scale. Included are the impedance l.........Page 199
Figure 18. Overlay of synthetic seismogram and SCS Line EW9417-13 at Site 998, with depth and age.........Page 200
Figure 19. Correlation of Site 998 lithostratigraphic units and core lithologies with SCS Line EW.........Page 201
Figure 5. Density log and physical properties density measurements for Site 1000.......Page 193
Figure 11. Site 1000 composite velocity profile containing edited sonic log and physical properti.........Page 196
Figure 13. Site 1001 composite velocity profile containing edited sonic log and physical properti.........Page 197
Figure 21. Correlation and noncorrelation of several lithologic events from Site 1000 with SCS Li.........Page 202
Figure 23. Correlation of Site 1001 lithostratigraphic units and core lithologies with SCS Line E.........Page 203
DATA......Page 204
Figure 3. Two-way traveltime vs. depth below seafloor calculated from compressional velocities un.........Page 207
Figure 4. Velocity, density, and resistivity (medium induction resistivity tool) along with calip.........Page 208
Figure 5. Far-field source wavelet as represented by a 10-trace average of the seafloor reflectio.........Page 209
Figure 1. Bathymetric map (1000-m contour interval from ETOPO-5) showing the location of Site 999.........Page 205
Figure 2. An ~4-km portion of IG2901 MCS Line CT1-12a is displayed with a vertical exaggeration o.........Page 206
METHODS......Page 210
Figure 1. General map of the Western Caribbean. The Colombian Basin and the Nicaraguan Rise are c.........Page 211
Figure 3. Paragenesis of cavity fills.......Page 212
Figure 4. Macroscopic fracture-filling carbonate phases. A. Lens of fine- grained carbonate sedim.........Page 213
Figure 5. Optical microphotographs. A. Overview of laminated micrite 2 (m2) and sparry calcite 2 .........Page 214
Figure 6. SEM photomicrographs. A. General aspect of micrite 1 (m1). Note the smooth surfaces of .........Page 215
RESULTS......Page 216
Figure 2. TiO2 vs. MgO diagram comparing the Site 1001 basalt glass reported in this paper and th.........Page 218
Table 2. 40Ar-39Ar plateau and isochron age calculations, Site 1001.......Page 217
HYDROGRAPHIC CONSIDERATIONS......Page 220
Figure 2. Vertical structure of Cariaco Basin upper water column derived from time-series data. T.........Page 221
Table 1 (continued).......Page 223
Figure 4. Alkenone records of concentration (µg/g dry sediment) and temperature estimated from th.........Page 224
REFERENCES......Page 227
Figure 6. Comparison of total organic carbon (TOC) record (Haug et al., 1998) and the alkenone co.........Page 225
Table 1. Results of alkenone analyses of Hole 1002C.......Page 222
INTRODUCTION......Page 229
METHODS AND MATERIALS......Page 231
Table 1. Location, coordinates, and water depth of the cores.......Page 235
Figure 14. Variations of benthic delta13C compared to carbonate mass accumulation rates (CO3 MAR) in .........Page 243
CONCLUSIONS......Page 251
REFERENCES......Page 252
Figure 1. A. Carbonate mass accumulation rates (CO3 MARs) for the eastern equatorial Pacific, ODP.........Page 230
Figure 2. A. Tectonic and paleoceanographic evolution of the Central American Seaway with inferre.........Page 232
Figure 4. Detailed bathymetry in Pedro Channel and Walton Basin (Cunningham, 1998) represents the.........Page 233
Figure 5. Simplified reconstruction sketches of the Caribbean (after Pindell, 1994) illustrating .........Page 234
Table 2. Leg 165 datums for nannostratigraphy, planktonic foraminiferal stratigraphy, and magneto.........Page 236
Figure 8. A. Shipboard datums of planktonic foraminifers, nannofossils, and magnetic reversals (S.........Page 237
Figure 9. Comparison of two carbonate-content data sets derived from Leg 165 shipboard analyses a.........Page 238
Figure 10. Sand-sized fraction, a proxy for carbonate dissolution, compared to carbonate mass acc.........Page 239
Table 3. Correlation coefficient of carbonate content among Sites 998, 999, and 1000.......Page 240
Figure 12. Carbonate mass accumulation rates (CO3 MARs) for (A) Hole 998A, (B) Hole 999A, and (C).........Page 241
Figure 13. Variations of benthic delta18O in Holes (A) 998A, (B) 999A, and (C) 1000A. Bulk sample delta18.........Page 242
Figure 15. Variations of carbonate-content values between 16 and 8 Ma in three different areas of.........Page 245
Figure 16. A. Correlation between fluctuation of North Atlantic Deep Water (NADW) production (fro.........Page 246
Figure 17. Summary chart of paleoceanographic, tectonic, floral, faunal, and sedimentary changes .........Page 248
Figure 18. A. delta13C of the modern equatorial Indian, western Pacific, and western Atlantic oceans .........Page 249
METHODS......Page 254
Table 1. Conversion of Miocene oxygen- and carbon-isotope events from the geomagnetic polarity ti.........Page 255
Figure 2. Lithostratigraphic units in the investigated interval at Site 999 (Subunits IC, IIA, an.........Page 256
Figure 5. Oxygen-isotope data from Site 999 (this study) plotted against carbonate content (Sigur.........Page 258
Figure 9. Oxygen-isotope data for Sites 1000 and 999 plotted against age. The chronologies at bot.........Page 260
Figure 10. Carbon-isotope data for Sites 1000 and 999 plotted against age. The chronologies at bo.........Page 261
Figure 4. Carbon- and oxygen-isotope data from Site 999. Gray and white intervals correspond to l.........Page 257
Figure 7. Carbon- and oxygen-isotope data from Site 1000 smoothed by a 5-running average. Note th.........Page 259
Figure 1. Site locations for ODP Leg 165. Water depths (drill-pipe measurements from sea level) f.........Page 263
Table 1. Representative reactions.......Page 264
Table 3. Geochemical data for discrete ash* layers.......Page 267
Figure 9. Depth profile for total organic carbon (TOC) for Site 1000 reported as weight percent o.........Page 269
Figure 11. Depth profiles for calcium (open and solid circles) and magnesium (open and solid squa.........Page 270
Figure 16. Depth profile for silica in Site 999 interstitial waters. Distribution of discrete ash.........Page 272
Figure 17. Depth profiles for rubidium in Site 999 interstitial waters. Distributions of both dis.........Page 273
Table 2. Modeled sulfate reduction rates.......Page 265
Figure 3. Downcore distribution of total sulfur concentrations at Site 999 reported as weight per.........Page 266
Figure 7. Depth profile for total alkalinity in Site 1000 interstitial waters. Bulk sediment calc.........Page 268
Figure 14. Depth profile for total alkalinity in Site 998 interstitial waters. Distribution of di.........Page 271
ANALYTICAL METHODS......Page 275
Figure 1. Location of sites drilled during Leg 165, discussed in the text.......Page 276
Figure 2. The accumulation rate of tephra layers at sites drilled during Leg 165, expressed as as.........Page 277
Figure 6. Photograph of a typical Miocene silicic tephra fall layer in a Leg 165 sediment core, s.........Page 286
REFERENCES......Page 289
Table 1: 40Ar/39Ar Dating of biotites from Leg 165 tephra layers.......Page 278
Figure 4. Comparison of radiometric dates of Caribbean tephra layers and the Neogene biostratigra.........Page 283
Figure 5. The plate tectonic configuration of the volcanic arc that comprised the Cayman Rise and.........Page 285
Figure 7. The relationship between Miocene Central American ignimbrite volcanism (Tertiary volcan.........Page 287
Figure 8. A comparison of the Caribbean record of explosive volcanism (tephra accumulation rate a.........Page 288
Table 1 (continued).......Page 279
Table 1 (continued).......Page 280
Table 2. Comparison of Leg 165 40Ar/39Ar radiometric dates of tephra layers vs. biostratigraphic .........Page 281
Table 3: 40Ar/39Ar Dating of feldspars in Leg 165 tephra layer.......Page 282
INDEX TO VOLUME 165......Page 291
VOLUME 165 SUBJECT INDEX......Page 292
Campanian (cont.)......Page 293
dissolution......Page 294
dissolution (cont.)......Page 295
lithostratigraphy......Page 296
lithostratigraphy (cont.)......Page 297
Panama, Isthmus of......Page 298
Panama, Isthmus of (cont.)......Page 299
Site 998......Page 300
Site 998 (cont.)......Page 301
well-log Unit 1......Page 302
VOLUME 165 TAXONOMIC INDEX......Page 303
Discoaster berggrenii......Page 304
Discoaster berggrenii (cont.)......Page 305
insueta s. l., Globigerinatella......Page 306
insueta s. l., Globigerinatella (cont.)......Page 307
rugosus, Ceratolithus......Page 308
rugosus, Ceratolithus (cont.)......Page 309
Zygrhablithus bijugatus......Page 310
Appendix B. Stratigraphic distribution of calcareous nannofossils, Hole 998A.......Page 311
Part 1......Page 312
Part 2......Page 313
Part 3......Page 314
Part 4......Page 315
Part 5......Page 316