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- Chapter contents
- Background and objectives
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Operations
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Logging while drilling
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Lithology
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Structural geology
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Biostratigraphy
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Geochemistry
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Physical properties
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Paleomagnetism
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Cuttings-core-log-seismic integration
- References
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Figures
- F1. Location map.
- F2. In-line 2529.
- F3. In-line 2532 and Cross-line 6223.
- F4. Map of drilled holes.
- F5. Wind conditions.
- F6. MWD logs, Hole C0002F.
- F7. Logs, Holes C0002A and C0002F.
- F8. LWD data, Hole C0002F.
- F9. Deep RAB images, Hole C0002F.
- F10. Shallow resistivity and fractures, Hole C0002F.
- F11. Borehole breakout and DITF azimuths, Hole C0002F.
- F12. Borehole breakout width, Hole C0002F.
- F13. Borehole breakouts, Hole C0002F.
- F14. DITFs, Hole C0002F.
- F15. Borehole breakouts, Holes C0002A and C0002.
- F16. Resistivity, gamma ray, porosity, and density, Hole C0002F.
- F17. Relogged resistivity, Hole C0002F.
- F18. Silty claystone vs. sand/sandstone, Hole C0002F.
- F19. Dominant lithologies, Hole C0002F.
- F20. Microscopic cuttings, Hole C0002F.
- F21. Q-index (1685.5 mbsf), Hole C0002F.
- F22. Q-index, Hole C0002F.
- F23. Mineralogy, Hole C0002F cuttings.
- F24. Mineralogy, Hole C0002F cuttings.
- F25. Mineralogy and fossils, Hole C0002F cuttings.
- F26. Mineralogy and fossils, Hole C0002F cuttings.
- F27. Calcium carbonate, Hole C0002F.
- F28. XRD data, Hole C0002F 1–4 and >4 mm cuttings.
- F29. XRD data, Hole C0002F 1–4 mm cuttings.
- F30. XRF major elements, Hole C0002F 1–4 and >4 mm cuttings.
- F31. XRF major elements, Hole C0002F 1–4 mm cuttings.
- F32. Lithologic column, Core 338-C0002H-1R.
- F33. Lithologic column, Core 338-C0002H-2R.
- F34. Petrographic features, Hole C0002H.
- F35. Bioturbation, Hole C0002H.
- F36. XRD mineralogy, Hole C0002H cores.
- F37. XRF chemical compositions, Hole C0002H cores.
- F38. Lithologic column, Hole C0002J.
- F39. XRD mineralogy, Hole C0002J cores.
- F40. XRF chemical compositions, Hole C0002J cores.
- F41. Nonvolcanic fragments, Hole C0002J.
- F42. Volcanogenic grains, Hole C0002J.
- F43. Discrete burrows associated with Unit III, Hole C0002J.
- F44. Syndepositional erosional processes in Unit III, Hole C0002J.
- F45. Glauconite, Hole C0002J.
- F46. Microcrystalline carbonate lithology, Hole C0002J.
- F47. Possible unit boundary zone, Hole C0002J.
- F48. Lithologic column, Holes C0002K and C0002L.
- F49. XRD mineralogy, Hole C0002K and C0002L cores.
- F50. XRF chemical compositions, Hole C0002K and C0002L cores.
- F51. Sand grain types, Holes C0002K and C0002L.
- F52. Turbidite variations, Hole C0002K and C0002L cores.
- F53. Sand occurrence, Holes C0002K and C0002L.
- F54. Deformation structure distribution, Hole C0002F cuttings.
- F55. Vein structures, Hole C0002F >4 mm cuttings.
- F56. Carbonate veins, Hole C0002F cuttings.
- F57. Slickenlined surfaces, Hole C0002F cuttings.
- F58. Deformation structure distribution vs. silty claystone, Hole C0002F cuttings.
- F59. Minor faults, Hole C0002F.
- F60. Sandstone cuttings, Hole C0002F.
- F61. Silty claystone cuttings, Hole C0002F.
- F62. Drilling disturbance structures, Hole C0002F.
- F63. Silty claystone concentrations, Hole C0002F.
- F64. Structures on working halves, Hole C0002J.
- F65. Bedding dip angle variation, Holes C0002H and C0002J–C0002L.
- F66. Poles to bedding, Holes C0002H and C0002J.
- F67. Fault, joint, and deformation band dip angle variation.
- F68. Fault orientations, Holes C0002H and C0002J.
- F69. Normal fault zone, Hole C0002H.
- F70. Deformation bands, Hole C0002J.
- F71. Geochemical parameters and salt concentrations.
- F72. Standard squeezing vs. GRIND method.
- F73. Headspace gas data.
- F74. Methane, ethane, and propane in headspace gas.
- F75. Methane, organic matter, and Rn data.
- F76. C1/(C2 + C3) and δ13C-CH4.
- F77. Relationship between C1/(C2 + C3) and δ13C-CH4.
- F78. Hydrocarbon gas and total gas.
- F79. Ethane and propane data.
- F80. PGMS, Rn, and CO2.
- F81. Total gas and Bernard parameters.
- F82. HC and nonHC gas package boundaries.
- F83. CaCO3, TOC, TN, and C/N, Holes C0002F and C0002B.
- F84. CaCO3, TOC, TN, TS, and C/N, Holes C0002B, C0002H, C0002J–C0002L, and C0002F.
- F85. MSCL-W measurements.
- F86. MAD measurements on cores.
- F87. Thermal conductivity.
- F88. VP and electrical resistivity.
- F89. Electrical resistivity, Holes C0002K and C0002L.
- F90. Electrical resistivity with Archie parameters, Holes C0002K and C0002L.
- F91. Cementation factor versus electrical resistivity.
- F92. Electrical resistivity, Holes C0002H and C0002J–C0002L.
- F93. Undrained shear strength.
- F94. Color reflectance.
- F95. MAD data, Hole C0002F cuttings.
- F96. Cuttings grain density, bulk density, and porosity.
- F97. Cuttings porosity.
- F98. DICAs and time off bottom.
- F99. Cuttings mass magnetic susceptibility.
- F100. Cuttings and core NGR.
- F101. MSCL-W NGR and cuttings grain density.
- F102. Cuttings bags.
- F103. Gray color distribution.
- F104. Mean gray values.
- F105. Salinity index distribution.
- F106. Dielectric constant and dispersion and electrical conductivity, Hole C0002F.
- F107. Dielectric dispersion vs. dielectric constant.
- F108. Electrical resistivity, Hole C0002F.
- F109. LOT borehole configuration.
- F110. LOT pressure and mud flow rate.
- F111. Declination and inclination.
- F112. Magnetic fabric, Holes C0002K and C0002L.
- F113. Progressive AF demagnetization.
- F114. AMS parameter T, Holes C0002H and C0002J–C0002L.
- F115. Cuttings-core-log-seismic integration.
- F116. NGR at Unit III/IV boundary.
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Tables
- T1. BHA components.
- T2. LWD data, Hole C0002F.
- T3. Time off bottom, Hole C0002F.
- T4. Logging units, Hole C0002F.
- T5. Structural features, Hole C0002F.
- T6. Lithologic units, Hole C0002F.
- T7. Silty clay(stone), sand(stone), induration, grain shape, and fossil content, Hole C0002F.
- T8. Q-index, Hole C0002F.
- T9. XRD results, Hole C0002F.
- T10. XRF results, Hole C0002F.
- T11. Core recovery, Hole C0002H.
- T12. XRD results, Hole C0002H.
- T13. CaCO3, TN, TC, TS, TOC, C/N, and C/S, Holes C0002H and C0002J–C0002L.
- T14. XRF results, Hole C0002H.
- T15. Core intervals, Hole C0002J.
- T16. XRD results, Hole C0002J.
- T17. XRF results, Hole C0002J.
- T18. XRF data, Section 338-C0002J-5R-8.
- T19. Calcareous nannofossils, Hole C0002F.
- T20. Calcareous nannofossils, Hole C0002J.
- T21. Radiolarians, Hole C0002F.
- T22. Pliocene sediment/Miocene rock boundary data.
- T23. Core recovery, Holes C0002K and C0002L.
- T24. XRD results, Holes C0002K, and C0002L.
- T25. XRF results, Holes C0002K, and C0002L.
- T26. Sand occurrences, Holes C0002K, and C0002L.
- T27. Calcareous nannofossils, Hole C0002K.
- T28. Calcareous nannofossils, Hole C0002L.
- T29. IW geochemistry, Holes C0002J–C0002L.
- T30. Water content, Holes C0002H and C0002J–C0002L.
- T31. IW geochemistry, Holes C0002H and C0002J–C0002L.
- T32. IW geochemistry, Hole C0002F.
- T33. Core liner liquid, Holes C0002H and C0002J–C0002L.
- T34. Hydrocarbon gas, conventional extraction.
- T35. Hydrocarbon gas, additional extraction.
- T36. Hydrocarbon gas in void gas.
- T37. Carbon and nitrogen data, Hole C0002F.
- T38. Core liner thickness errors.
- T39. MAD measurements.
- T40. Resistivity, Holes C0002H and C0002J.
- T41. P-wave velocity results.
- T42. Electrical resistivity, Holes C0002K and C0002L.
- T43. UCS tests.
- T44. Gray value results.
- T45. Dielectric measurements and salinity index.
- T46. LOT key data.
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doi:10.2204/iodp.proc.338.103.2014
Biostratigraphy
Preliminary biostratigraphy for Hole C0002F is based on shore-based examination of calcareous nannofossils and radiolarians, whereas that for Holes C0002J–C0002L is exclusively based on calcareous nannofossils.
Calcareous nannofossils from Hole C0002F suggest that cuttings samples from 935.5 and 985.5 mbsf are early to middle Pliocene and late Miocene in age, respectively. These nannofossil ages likely reflect that the majority of cuttings at 935.5 mbsf are derived from Unit III, whereas those at 985.5 mbsf are derived from Unit IV. Radiolarian ages, which are less precise, are overall consistent with this interpretation. In this hole, a discrepancy between the logging Unit III/IV boundary (918.5 mbsf) and the lithologic Unit III/IV boundary (1025.5 mbsf) is considered to be due to mixing of cuttings over an interval of as much as ~100 m (see the “Methods” chapter [Strasser et al., 2014a]). Mixing of nannofossils occurs accordingly.
Calcareous nannofossils from Hole C0002J suggest that sediment above 925.5 mbsf is middle to late Pliocene in age, whereas sediment below 926.7 mbsf contains rare nannofossils. This supports the lithologic Unit III/IV boundary at 926.7 mbsf in this hole, below which sediment of Unit IV is noncalcareous and supposed to have been deposited below the carbonate compensation depth (see “Lithology”).
The age range of the Kumano Basin section between 200 and 500 mbsf in Holes C0002K and C0002L was constrained from biostratigraphy and magnetostratigraphy data from Expedition 315 to be older than 1.04 Ma but younger than 1.34 Ma (Expedition 315 Scientists, 2009b). Calcareous nannofossils from Hole C0002L confirmed that the base of this hole (502.74 mbsf) is older than 1.34 Ma. The nannofossil event of 1.04 Ma, however, was found at ~250 mbsf in Hole C0002K, so an interval of normal polarity paleomagnetism between 240.72 and 299.37 mbsf (see “Paleomagnetism”) may rather be correlated with the Jaramillo Subchron of 0.988–1.07 Ma. However, this nannofossil event and the top of the Jaramillo Subchron were also encountered at 137.46 and 119.58 mbsf, respectively, in Hole C0002D. The duplicate occurrence of the nannofossil event and the Jaramillo Subchron is possibly due to the presence of a normal fault between Holes C0002D and C0002K, where the former hole penetrated the footwall and the latter hole penetrated the hanging wall.
Calcareous nannofossils
Calcareous nannofossils of 17 cuttings samples (338-C0002F-22-SMW [935.5 mbsf] to 284-SMW [1985.5 mbsf]) from Hole C0002F, 9 core samples (338-C0002J-1R-CC, 0–5 cm, to 7R-CC, 19.5–24.5 cm) from Hole C0002J, 8 core samples (338-C0002K-1H-CC, 36.0–41.0 cm, to 11X-CC, 20.0–25.0 cm) from Hole C0002K, and 14 core samples (338-C0002L-1X-CC, 36.0–41.0 cm, to 24X-CC, 33.5–38.5 cm) from Hole C0002L were examined. Well to poorly preserved, abundant nannofossil specimens are found in these holes.
Hole C0002F
The uppermost sample (338-C0002F-22-SMW; 935.5 mbsf) examined contains Reticulofenestra pseudoumbilicus and Sphenolithus spp. without a typical form of Discoaster quinqueramus (Table T19). This together with other accompanying nannofossil species indicate that this sample may be assigned a Pliocene age, corresponding to calcareous nannofossil Zones NN15–NN12 (Table T19; see also Table T11 in the “Methods” chapter [Strasser et al., 2014a]). D. quinqueramus and/or Discoaster berggrenii, which characterize the Miocene nannofossil Zone CN9 (NN11) (Table T11 in the “Methods” chapter [Strasser et al., 2014a]), consistently occur below Sample 338-C0002F-34-SMW (985.5 mbsf) (Table T19). This may indicate that the entire section to 1986 mbsf is younger than 5.59 Ma. However, the occurrence of nannofossils becomes sporadic in the lower part of the hole and species composition is incomplete. Therefore, downhole contamination by those younger species cannot be excluded.
Hole C0002J
The presence of Discoaster tamalis and the absence of Sphenolithus spp. indicate that Sample 338-C0002J-1R-CC (906.085 mbsf) is clearly correlated with nannofossil Zone NN16 and corresponds to 2.87–3.65 Ma (Table T20). Moreover, the last occurrence (LO) of Sphenolithus spp. is placed between Samples 338-C0002J-1R-CC and 2R-CC (907.85 mbsf). The interval between Samples 338-C0002J-4R-CC (921.78 mbsf) and 5R-7 (925.481 mbsf) may coincide with nannofossil Zone NN14–NN15 because of the consistent occurrence of middle Pliocene species. No age indication is obtained below Sample 338-C0002J-5R-8 (926.7 mbsf) because these samples are barren of nannofossils.
Hole C0002K
The uppermost sample (338-C0002K-1H-CC; 204.48 mbsf) contains dominant Reticulofenestra asanoi along with common occurrence of medium Gephyrocapsa spp. (≥4 µm) (Table T27). The first occurrence of medium Gephyrocapsa spp. (≥4 µm) (= Gephyrocapsa sp. 3) is placed between Samples 338-C0002K-7X-CC (244.58 mbsf) and 8X-CC (254.83 mbsf), which provides an age of 1.04 Ma. R. asanoi is continuously observed to the lowermost sample, and thus, this hole is entirely correlated with the interval above the first consistent occurrence (FCO) of this species (i.e., younger than 1.078–1.136 Ma) (note that according to Raffi [2002] this event is diachronous in the world’s oceans; we therefore assigned the medium age of 1.107 Ma).
Hole C0002L
The FCO of R. asanoi, which occurs at 1.107 Ma, is placed between Samples 338-C0002L-4H-CC (314.49 mbsf) and 5H-CC (324.23 mbsf) (Table T28). The LO of Gephyrocapsa spp. (>5.5 µm), corresponding to 1.24 Ma, is found between Samples 338-C0002L-5H-CC and 6H-CC (333.98 mbsf). Samples from 338-C0002L-6H-CC to 24X-CC (502.74 mbsf) are correlated with the interval between the LO of Gephyrocapsa spp. (>5.5 µm) and that of Helicosphaera sellii, which corresponds to 1.24–1.34 Ma.
Radiolarians
Radiolarians in Hole C0002F are present in 4 samples and absent from the other 19 samples examined. In the four samples, radiolarians are rare to very rare and show signs of dissolution (moderate preservation) (Table T21). The occurrences of Stichocorys delmontensis from Sample 338-C0002F-22-SMW (935.5 mbsf) and of Stichocorys peregrina from Sample 34-SMW (985.5 mbsf) indicate that the two samples can be correlated to the Lychnodictyum audax Zone (RN11) or older zones (i.e., 2.7 Ma or older [Pliocene–Miocene]). No age-diagnostic radiolarian species were found from Samples 46-SMW and 56-SMW.
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