High Resolution Guaymas Basin Geochemical, Diatom, and Silicoflagellate Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: High Resolution Guaymas Basin Geochemical, Diatom, and Silicoflagellate Data LAST UPDATE: 2/2005 (Original receipt by WDC Paleo) CONTRIBUTOR: John A. Barron, U.S. Geological Survey IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2005-022 SUGGESTED DATA CITATION: Barron, J.A., et al. 2005. High Resolution Guaymas Basin Geochemical, Diatom, and Silicoflagellate Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2005-022. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Barron, J.A., D. Bukry, and J.L. Bischoff. 2004. High resolution paleoceanography of the Guaymas Basin, Gulf of California, during the past 15,000 years. Marine Micropaleontology, v.50 (2004) pp. 185-207. ABSTRACT: Deep Sea Drilling Project Site 480 (27°54.10'N, 111°39.34'W; 655 m water depth) contains a high resolution record of paleoceanographic change of the past 15,000 years for the Guaymas Basin, a region of very high diatom productivity within the central Gulf of California. Analyses of diatoms and silicoflagellates were completed on samples spaced every 40-50 yr, whereas ICP-AES geochemical analyses were completed on alternate samples (sample spacing 80-100 yr). The Bolling-Allerod interval (14.6-12.9 ka) (note, ka refers to 1000 calendar years BP throughout this report) is characterized by an increase in biogenic silica and a decline in calcium carbonate relative to surrounding intervals, suggesting conditions somewhat similar to those of today. The Younger Dryas event (12.9-11.6 ka) is marked by a major drop in biogenic silica and an increase in calcium carbonate. Increasing relative percentage contributions of Azpeitia nodulifera and Dictyocha perlaevis (a tropical diatom and silicoflagellate, respectively) and reduced numbers of the silicoflagellate Octactis pulchra are supportive of reduced upwelling of nutrient-rich waters. Between 10.6 and 10.0 ka, calcium carbonate and A. nodulifera abruptly decline at DSDP 480, while Roperia tesselata, a diatom indicative of winter upwelling in the modern-day Gulf, increases sharply in numbers. A nearly coincident increase in the silicoflagellate Dictyocha stapedia suggests that waters above DSDP 480 were more similar to the cooler and slightly more saline waters of the northern Gulf during much of the early and middle parts of the Holocene (~10 to 3.2 ka). At about 6.2 ka a stepwise increase in biogenic silica and the reappearance of the tropical diatom A. nodulifera marks a major change in oceanographic conditions in the Gulf. A winter shift to more northwesterly winds may have occurred at this time along with the onset of periodic northward excursions (El Nino-driven?) of the North Equatorial Countercurrent during the summer. Beginning between 2.8 and 2.4 ka, the amplitude of biogenic silica and wt% Fe, Al, and Ti (proxies of terrigenous input) increase, possibly reflecting intensification of ENSO cycles and the establishment of modern oceanographic conditions in the Gulf. Increased numbers of O. pulchra after 2.8 ka suggest enhanced spring upwelling. GEOGRAPHIC REGION: Guaymas Basin, Gulf of California, Mexico. PERIOD OF RECORD: 15 - 1 KYrBP DESCRIPTION: High Resolution Guaymas Basin geochemical, diatom, and silicoflagellate data. Deep Sea Drilling Project Site 480 (27°54.10'N, 111°39.34'W; 655 m water depth) DATA: 1. Geochemistry Barron et al., 2004 Table 2. Results of ICP-AES geochemical and couometric analyses at DSDP 480 (see methods section). Mbsf = meters below sea floor; ka* = 1000 cal yr B.P. Ba and Sr in ppm. Depth Age %Al %Si %Fe %Ti %Mg %K %P Ba Sr %Tot.C %TIC %TOC %CaCO3 %Bio.Si 0.00 1.33 4.10 25.8 2.10 0.21 1.32 1.93 0.10 940 153 4.64 0.00 4.64 0.00 26.8 0.10 1.42 1.04 28.0 1.89 0.20 1.33 1.75 0.09 533 151 3.93 0.00 3.93 0.00 53.7 0.20 1.51 3.87 25.8 1.85 0.20 1.44 1.69 0.10 575 158 3.69 0.00 3.69 0.00 28.4 0.30 1.60 3.83 25.0 1.85 0.20 1.39 1.62 0.09 531 154 3.92 0.00 3.92 0.00 27.0 0.40 1.69 3.47 25.7 1.61 0.18 1.34 1.69 0.12 545 149 4.03 0.00 4.03 0.00 31.1 0.50 1.77 2.66 27.8 1.29 0.14 1.23 1.18 0.07 442 128 3.28 0.00 3.28 0.00 41.5 0.60 1.86 3.46 25.6 1.63 0.17 1.36 1.42 0.12 539 146 3.85 0.00 3.85 0.00 31.0 0.70 1.95 3.32 26.8 1.61 0.18 1.27 1.43 0.10 397 138 3.31 0.00 3.31 0.00 34.6 0.80 2.04 3.75 25.6 1.69 0.19 1.38 1.78 0.10 508 161 3.37 0.00 3.37 0.00 28.9 0.90 2.12 3.32 26.3 1.53 0.17 1.31 1.43 0.08 472 146 3.45 0.01 3.44 0.08 33.5 1.00 2.21 4.43 24.5 2.17 0.23 1.52 1.90 0.10 521 176 3.64 0.24 3.40 2.00 21.5 1.10 2.30 2.02 24.6 1.01 0.11 1.39 1.16 0.12 385 152 2.92 0.00 2.92 0.00 39.2 1.20 2.39 3.33 25.5 1.50 0.17 1.36 1.52 0.08 446 154 3.64 0.00 3.64 0.00 31.7 1.30 2.47 3.34 24.7 1.55 0.16 1.46 1.50 0.11 531 162 3.55 0.02 3.53 0.17 29.9 1.40 2.56 3.66 24.2 1.62 0.19 1.50 1.58 0.08 458 170 3.43 0.01 3.42 0.08 26.4 1.50 2.65 3.52 24.4 1.58 0.18 1.57 1.51 0.09 498 172 3.33 0.01 3.32 0.08 27.9 1.60 2.74 4.66 27.2 2.16 0.24 1.27 1.83 0.11 562 149 4.05 0.00 4.05 0.00 25.8 1.70 2.83 3.46 28.2 1.61 0.17 1.19 1.46 0.08 521 132 3.85 0.00 3.85 0.00 36.6 1.80 2.91 3.46 26.9 1.59 0.19 1.30 1.49 0.10 437 143 3.31 0.00 3.31 0.00 33.8 1.90 3.00 3.77 26.2 1.73 0.19 1.33 1.50 0.09 480 144 3.65 0.00 3.65 0.00 30.0 2.00 3.09 3.84 25.3 1.71 0.19 1.41 1.50 0.11 521 153 4.07 0.00 4.07 0.00 27.5 2.10 3.18 4.24 25.9 1.97 0.21 1.41 1.71 0.10 507 162 3.62 0.00 3.62 0.00 26.0 2.20 3.26 3.41 26.1 1.58 0.17 1.32 1.37 0.07 387 146 3.13 0.00 3.13 0.00 32.4 2.30 3.35 3.80 25.6 1.93 0.19 1.47 1.53 0.08 466 155 3.32 0.00 3.32 0.00 28.5 2.40 3.44 3.40 25.4 1.76 0.17 1.39 1.38 0.10 514 149 3.98 0.00 3.98 0.00 30.9 2.50 3.53 3.96 26.7 1.82 0.20 1.43 1.58 0.08 470 155 3.28 0.01 3.27 0.08 29.7 2.59 3.61 4.31 24.7 2.17 0.22 1.55 1.62 0.09 520 207 3.59 0.27 3.32 2.25 22.8 2.70 3.70 3.75 25.6 1.80 0.19 1.48 1.50 0.07 516 159 3.55 0.02 3.53 0.17 28.9 2.80 3.79 3.49 25.2 1.66 0.17 1.25 1.42 0.09 442 165 3.59 0.00 3.59 0.00 29.9 2.90 3.88 3.77 25.9 1.86 0.20 1.53 1.52 0.09 536 166 3.74 0.00 3.74 0.00 29.4 3.00 3.97 3.21 25.2 1.58 0.16 1.44 1.44 0.07 453 148 3.17 0.00 3.17 0.00 31.9 3.00 3.97 3.25 22.8 1.49 0.17 1.84 1.40 0.07 432 159 3.25 0.00 3.25 0.00 26.3 3.10 4.05 3.57 28.0 1.65 0.18 1.22 1.43 0.07 422 148 3.10 0.00 3.10 0.00 35.4 3.20 4.14 4.39 24.7 1.99 0.21 1.45 1.71 0.09 537 210 4.28 0.30 3.98 2.50 22.3 3.30 4.23 3.52 26.3 1.68 0.18 1.37 1.40 0.08 543 160 4.01 0.02 3.99 0.17 32.0 3.40 4.32 3.87 26.0 1.85 0.18 1.31 1.50 0.08 479 145 3.65 0.00 3.65 0.00 28.9 3.50 4.40 3.89 26.1 1.82 0.19 1.34 1.55 0.08 519 151 3.69 0.00 3.69 0.00 28.9 3.60 4.49 3.47 26.5 1.59 0.17 1.35 1.36 0.07 451 142 3.51 0.00 3.51 0.00 32.8 3.70 4.58 3.95 24.5 1.85 0.19 1.54 1.56 0.07 510 171 3.41 0.00 3.41 0.00 25.0 4.75 5.50 3.78 26.2 1.84 0.20 1.25 1.46 0.11 575 152 3.54 0.07 3.47 0.58 30.0 4.85 5.59 4.00 26.7 1.90 0.20 1.31 1.55 0.07 556 142 4.10 0.00 4.10 0.00 29.5 4.95 5.68 4.11 28.3 1.81 0.19 1.39 1.59 0.07 602 149 3.89 0.00 3.89 0.00 32.2 5.05 5.76 4.15 25.6 1.88 0.20 1.40 1.56 0.11 651 160 3.20 0.01 3.19 0.08 26.0 5.15 5.85 4.43 25.1 2.03 0.21 1.51 1.65 0.08 748 164 3.50 0.01 3.49 0.08 22.8 5.25 5.94 4.58 25.6 2.01 0.21 1.50 1.67 0.08 615 154 3.62 0.01 3.61 0.08 22.9 5.35 6.03 4.18 26.8 1.89 0.19 1.35 1.60 0.08 621 161 3.61 0.01 3.60 0.08 28.4 5.45 6.12 3.99 26.7 1.74 0.19 1.39 1.52 0.07 632 155 3.36 0.03 3.33 0.25 29.5 5.55 6.20 3.55 28.1 1.60 0.18 1.25 1.35 0.06 519 131 2.96 0.00 2.96 0.00 35.8 5.65 6.29 3.80 26.7 1.89 0.19 1.38 1.46 0.08 609 142 2.72 0.00 2.72 0.00 30.9 5.75 6.38 4.03 27.7 1.83 0.20 1.37 1.56 0.08 651 148 3.21 0.00 3.21 0.00 31.4 5.85 6.47 4.71 26.0 2.08 0.22 1.45 1.74 0.09 690 157 3.10 0.00 3.10 0.00 22.8 5.95 6.55 4.67 25.7 2.15 0.22 1.54 1.73 0.10 667 161 3.19 0.00 3.19 0.00 22.4 6.05 6.64 4.59 24.6 2.05 0.21 1.59 1.95 0.08 680 164 3.63 0.01 3.62 0.08 20.6 6.15 6.73 5.07 23.5 2.19 0.23 1.76 1.86 0.08 647 173 3.52 0.00 3.52 0.00 14.7 6.25 6.82 5.08 25.7 2.22 0.23 1.40 1.88 0.09 674 156 3.58 0.00 3.58 0.00 19.5 6.35 6.90 4.53 26.6 1.96 0.21 1.37 1.69 0.09 478 146 4.25 0.00 4.25 0.00 25.4 6.45 6.99 4.95 26.1 2.19 0.23 1.53 1.90 0.09 413 163 3.76 0.00 3.76 0.00 21.3 6.55 7.08 5.10 22.7 2.23 0.23 1.52 1.95 0.07 498 157 3.32 0.01 3.31 0.08 12.8 6.65 7.17 4.42 26.7 1.93 0.20 1.39 1.68 0.07 303 156 3.03 0.13 2.90 1.08 26.4 6.75 7.26 4.93 26.6 2.27 0.24 1.46 1.95 0.08 445 150 3.13 0.00 3.13 0.00 22.5 6.85 7.34 4.40 26.8 1.85 0.20 1.34 1.75 0.07 465 140 3.21 0.01 3.20 0.08 26.8 6.95 7.43 5.52 28.2 2.26 0.25 1.50 2.14 0.09 469 158 3.38 0.00 3.38 0.00 21.7 7.05 7.52 5.17 26.0 2.17 0.23 1.41 1.90 0.09 474 148 3.11 0.01 3.10 0.08 19.5 7.15 7.61 4.14 26.9 1.85 0.20 1.39 1.73 0.09 421 139 2.72 0.00 2.72 0.00 28.9 7.25 7.69 5.33 24.8 2.37 0.26 1.53 2.00 0.09 610 163 3.88 0.00 3.88 0.00 15.7 7.35 7.78 5.17 24.3 2.37 0.24 1.61 1.94 0.09 467 156 3.78 0.00 3.78 0.00 15.7 7.45 7.87 4.44 25.1 1.85 0.20 1.43 1.72 0.08 425 145 3.51 0.00 3.51 0.00 22.8 7.55 7.96 4.71 25.8 2.12 0.22 1.47 1.87 0.07 402 147 3.30 0.02 3.28 0.17 22.4 7.65 8.04 4.00 25.2 1.78 0.18 1.64 1.61 0.07 278 136 2.91 0.01 2.90 0.08 26.2 7.75 8.13 4.66 27.5 2.06 0.22 1.32 1.76 0.07 368 133 3.06 0.00 3.06 0.00 26.4 7.85 8.22 3.86 28.3 1.60 0.17 1.18 1.60 0.06 294 131 2.95 0.00 2.95 0.00 34.0 7.95 8.31 3.93 26.5 1.68 0.17 1.35 1.56 0.07 268 161 3.17 0.20 2.97 1.67 29.5 8.05 8.40 5.06 26.6 2.14 0.23 1.42 1.93 0.16 423 159 2.81 0.00 2.81 0.00 21.6 8.15 8.48 5.35 26.1 2.15 0.24 1.47 2.08 0.09 370 166 3.31 0.03 3.28 0.25 18.4 8.25 8.57 4.74 25.4 2.06 0.22 1.34 1.91 0.08 462 157 3.78 0.01 3.77 0.08 21.3 8.35 8.66 5.48 24.8 2.23 0.24 1.37 2.05 0.09 457 172 3.07 0.00 3.07 0.00 14.6 8.45 8.75 4.80 26.3 2.09 0.22 1.37 1.88 0.08 456 143 3.10 0.01 3.09 0.08 22.8 8.55 8.83 4.69 23.6 2.15 0.22 1.48 1.86 0.08 450 167 3.05 0.00 3.05 0.00 17.7 8.65 8.92 4.73 24.6 2.00 0.21 1.57 1.90 0.14 434 151 3.45 0.01 3.44 0.08 19.6 9.50 10.10 5.24 24.7 2.43 0.22 1.31 2.00 0.08 553 235 4.30 0.28 4.02 2.33 16.1 9.60 10.27 5.84 24.9 2.57 0.26 1.42 2.18 0.09 473 259 4.13 0.63 3.50 5.25 12.2 9.70 10.43 4.94 25.6 2.25 0.23 1.41 1.93 0.07 356 171 3.14 0.12 3.02 1.00 20.3 9.80 10.60 5.29 25.0 2.37 0.25 1.46 2.06 0.07 405 197 3.42 0.23 3.19 1.92 16.4 9.90 10.77 5.24 25.1 2.32 0.25 1.49 2.01 0.12 381 177 3.09 0.10 2.99 0.83 17.0 10.00 10.93 5.77 24.3 2.68 0.27 1.48 2.21 0.08 434 234 3.66 0.46 3.20 3.83 11.4 10.10 11.10 5.64 25.9 2.28 0.24 1.39 2.26 0.14 431 171 3.00 0.03 2.97 0.25 15.8 10.20 11.27 5.49 23.7 2.20 0.24 1.29 2.12 0.07 467 189 3.13 0.01 3.12 0.08 12.1 10.30 11.43 5.31 24.9 2.35 0.25 1.38 2.08 0.07 398 223 3.13 0.39 2.74 3.25 16.0 10.40 11.60 6.08 25.0 2.39 0.26 1.39 2.33 0.09 440 171 3.16 0.02 3.14 0.17 10.7 10.50 11.77 5.56 21.2 2.45 0.25 1.28 2.10 0.09 694 387 4.87 1.63 3.24 13.58 6.2 10.60 11.93 5.68 21.0 2.41 0.26 1.32 2.18 0.11 469 423 4.79 1.78 3.01 14.83 4.8 10.70 12.10 5.73 21.0 2.43 0.25 1.32 2.22 0.11 425 377 4.74 1.47 3.27 12.25 4.5 10.80 12.27 5.65 21.6 2.42 0.25 1.33 2.31 0.10 438 349 4.47 1.29 3.18 10.75 6.4 10.90 12.43 5.40 20.4 2.30 0.24 1.45 2.13 0.10 384 373 4.54 1.35 3.19 11.25 5.6 11.00 12.64 5.70 21.6 2.50 0.25 1.28 2.36 0.12 427 404 4.79 1.62 3.17 13.50 6.0 11.10 12.82 5.47 21.0 2.31 0.24 1.25 2.31 0.13 458 420 4.79 1.61 3.18 13.42 6.4 11.20 12.95 5.55 21.6 2.33 0.25 1.31 2.42 0.10 413 383 4.58 1.47 3.11 12.25 7.1 11.30 13.04 4.70 27.1 1.90 0.20 1.26 2.23 0.08 335 188 3.26 0.23 3.03 1.92 25.3 11.40 13.13 5.89 25.0 2.39 0.26 1.38 2.71 0.12 458 188 3.47 0.02 3.45 0.17 12.1 11.50 13.22 4.88 25.6 1.98 0.22 1.26 2.20 0.25 350 168 2.68 0.03 2.65 0.25 20.7 11.60 13.31 4.85 27.3 2.13 0.22 1.34 2.15 0.09 366 168 2.66 0.01 2.65 0.08 24.6 11.70 13.40 4.93 26.1 2.04 0.22 1.34 2.18 0.10 365 167 3.56 0.01 3.55 0.08 21.4 11.80 13.48 5.00 27.1 2.18 0.22 1.23 2.31 0.08 363 160 2.70 0.02 2.68 0.17 23.1 11.90 13.57 4.91 26.3 1.84 0.21 1.22 2.25 0.10 352 153 2.67 0.00 2.67 0.00 22.0 12.00 13.66 3.54 28.0 1.55 0.16 1.20 1.73 0.07 254 130 2.24 0.00 2.24 0.00 35.6 12.10 13.75 5.18 27.5 1.95 0.24 1.24 2.01 0.10 395 159 2.57 0.00 2.57 0.00 22.7 12.20 13.84 4.79 26.7 1.91 0.21 1.21 1.83 0.07 360 149 2.85 0.00 2.85 0.00 23.7 12.30 13.93 3.56 25.8 2.15 0.16 1.18 1.44 0.09 259 147 2.20 0.01 2.19 0.08 30.7 12.40 14.02 4.97 24.9 2.19 0.22 1.50 1.88 0.10 337 170 2.61 0.00 2.61 0.00 18.5 12.50 14.11 4.87 26.8 2.15 0.23 1.29 1.81 0.10 518 172 3.06 0.01 3.05 0.08 23.4 12.60 14.20 4.54 25.7 1.86 0.21 1.27 1.74 0.08 318 174 2.41 0.00 2.41 0.00 23.4 12.70 14.29 5.24 25.7 2.07 0.23 1.26 2.01 0.08 430 180 3.38 0.02 3.36 0.17 18.3 12.80 14.38 4.40 26.7 1.97 0.20 1.22 1.76 0.11 360 182 2.75 0.22 2.53 1.83 26.6 12.90 14.47 4.93 26.0 2.04 0.22 1.28 1.89 0.06 370 204 3.01 0.38 2.63 3.17 21.2 13.00 14.56 3.83 26.1 1.71 0.17 1.12 1.54 0.07 286 250 3.24 0.76 2.48 6.33 29.4 13.10 14.65 5.73 20.3 2.53 0.27 1.36 2.21 0.09 416 428 4.92 1.81 3.11 15.08 3.0 13.20 14.73 6.01 21.1 2.57 0.28 1.32 2.31 0.09 523 397 4.12 1.42 2.70 11.83 2.7 13.41 14.92 4.86 20.3 2.12 0.21 1.25 1.92 0.11 408 415 5.06 1.73 3.33 14.42 9.2 13.51 15.01 5.39 19.4 2.57 0.26 1.34 2.11 0.29 508 498 5.65 1.99 3.66 16.58 3.4 13.61 15.10 5.95 23.3 2.97 0.31 1.34 2.27 0.14 584 296 3.68 0.57 3.11 4.75 7.9 13.71 15.19 5.96 23.5 2.92 0.31 1.39 2.33 0.36 514 289 3.70 0.65 3.05 5.42 8.3 2. Diatoms Barron et al., 2004 Table 3. Relative abundance of key diatom taxa in samples studied from DSDP 480 (see methods section). Column 1: Depth m. Column 2: Age KYrBP Column 3: Actinocyclus curvatulus Column 4: Actinocyclus octonarius Column 5: Actinoptychus spp. Column 6: Azpeitia nodulifer Column 7: Coscinodiscus spp. Column 8: Cyclotella spp. Column 9: Roperia tesselata Column 10: Stephanopyxis spp. Column 11: Number counted Depth Age A.curv. A.octon. ActinSpp. A.nodul. CoscinSpp. CyclotSpp. Rop.tess. StephanSpp. Num.counted 0.00 1.33 5 2 32 14 21 22 1 1 201 0.05 1.37 8 2 31 16 20 16 7 2 200 0.10 1.42 8 6 33 18 29 7 1 1 200 0.15 1.46 11 1 21 1 12 28 25 3 200 0.20 1.51 11 1 38 3 18 24 3 300 0.25 1.55 4 9 30 10 16 14 16 203 0.30 1.59 5 3 21 4 12 16 40 200 0.35 1.64 7 4 36 19 19 13 3 1 200 0.40 1.68 14 7 40 4 24 11 3 1 200 0.45 1.72 6 3 37 6 26 20 3 1 200 0.50 1.77 8 4 20 11 11 20 27 1 200 0.55 1.81 5 3 35 3 15 22 12 3 201 0.60 1.86 9 3 30 3 18 27 7 1 202 0.65 1.90 5 4 27 6 19 35 4 302 0.70 1.94 13 2 36 8 15 21 6 200 0.75 1.99 6 2 33 4 32 21 1 201 0.80 2.03 9 2 42 3 21 18 4 1 202 0.85 2.08 14 3 21 1 14 42 4 201 0.90 2.12 9 5 26 13 16 20 9 201 0.95 2.16 11 4 34 3 10 35 3 2 200 1.00 2.21 12 3 39 1 16 23 2 2 204 1.05 2.25 13 3 23 5 18 23 15 1 200 1.10 2.29 6 1 23 4 10 19 16 19 201 1.15 2.34 7 9 28 8 18 23 7 203 1.20 2.38 9 3 11 19 12 18 27 241 1.25 2.43 9 3 26 2 18 13 22 9 200 1.30 2.47 12 3 27 4 13 19 16 5 300 1.35 2.51 9 4 29 4 8 43 3 202 1.40 2.56 10 6 25 3 10 36 9 1 204 1.49 2.64 9 3 28 6 29 19 9 200 1.50 2.65 6 7 32 8 13 17 19 200 1.55 2.69 5 7 22 4 10 31 23 200 1.60 2.73 8 6 28 2 26 25 6 1 200 1.65 2.78 10 1 28 6 19 28 10 200 1.70 2.82 9 3 43 1 16 25 4 1 200 1.75 2.87 16 12 21 4 19 19 7 2 203 1.80 2.91 11 2 40 6 17 15 7 203 1.85 2.95 5 3 38 5 23 21 6 1 200 1.90 3.00 6 2 18 1 11 36 26 1 200 1.95 3.04 10 4 40 2 15 24 7 1 200 2.00 3.08 6 1 29 1 6 42 14 202 2.05 3.13 6 8 35 4 16 25 8 1 200 2.10 3.17 11 4 28 3 19 27 8 203 2.15 3.22 6 3 37 4 12 35 2 275 2.20 3.26 7 5 37 13 18 16 2 202 2.25 3.30 7 6 36 4 20 22 6 1 200 2.30 3.35 5 6 32 7 22 19 6 201 2.35 3.39 8 14 29 3 12 31 3 300 2.40 3.44 9 6 35 2 19 26 5 200 2.45 3.48 9 8 34 3 22 24 2 1 200 2.50 3.52 7 4 36 4 20 25 1 2 201 2.55 3.57 9 6 36 5 24 14 6 202 2.59 3.60 6 3 44 3 22 18 6 200 2.65 3.65 6 4 31 7 19 31 4 1 200 2.70 3.70 9 7 30 5 17 21 10 212 2.75 3.74 7 4 30 5 17 33 6 200 2.80 3.79 9 4 30 5 13 34 4 256 2.85 3.83 4 8 40 6 15 22 4 250 2.90 3.87 12 4 39 3 18 20 3 250 2.95 3.92 4 7 35 5 15 32 2 264 3.00 3.96 5 9 30 2 12 39 3 357 3.00 3.96 6 3 13 2 10 33 33 1 200 3.05 4.01 7 4 26 6 16 34 7 282 3.10 4.05 6 2 30 3 24 26 10 250 3.20 4.14 5 3 19 7 13 26 27 245 3.25 4.18 4 2 33 12 12 18 18 207 3.30 4.22 5 3 27 11 22 21 11 211 3.35 4.27 2 2 23 23 14 18 16 201 3.40 4.31 4 5 32 22 11 25 3 200 3.45 4.36 3 1 14 4 3 17 60 200 3.50 4.40 4 2 34 5 15 31 8 261 3.55 4.44 2 2 14 6 7 23 48 200 3.60 4.49 4 5 22 33 9 16 11 230 3.65 4.53 9 3 41 6 13 18 10 240 3.70 4.58 4 2 37 13 18 15 9 225 3.75 4.62 9 7 48 3 15 18 1 315 4.75 5.50 4 2 39 9 24 14 3 3 204 4.80 5.54 6 4 31 19 17 15 6 1 202 4.85 5.58 5 3 43 11 12 17 8 206 4.90 5.63 6 4 32 2 19 15 22 1 200 4.95 5.67 7 7 24 4 18 26 16 200 5.00 5.72 7 4 23 1 17 22 27 202 5.05 5.76 8 2 15 0 10 29 35 213 5.10 5.80 5 4 26 1 12 23 29 203 5.15 5.85 7 3 27 3 16 8 38 200 5.20 5.89 6 5 21 11 21 17 18 201 5.25 5.94 7 2 48 3 14 10 18 200 5.30 5.98 5 4 1 2 13 76 1 200 5.35 6.02 5 6 18 13 15 32 14 200 5.40 6.07 2 4 16 2 12 13 49 201 5.45 6.11 9 2 36 4 25 15 8 2 228 5.50 6.15 5 11 13 17 12 14 28 248 5.55 6.20 6 10 15 26 9 11 23 248 5.60 6.24 9 13 17 22 14 25 218 5.65 6.29 8 6 19 15 20 32 217 5.70 6.33 3 4 11 10 8 63 248 5.75 6.37 8 10 18 2 19 13 30 221 5.80 6.42 12 4 15 1 17 18 34 200 5.85 6.46 15 3 28 1 18 10 27 200 5.90 6.51 5 6 11 16 21 41 202 5.95 6.55 11 3 26 25 14 21 203 6.00 6.59 10 2 37 12 21 18 1 200 6.05 6.64 3 2 26 2 32 12 21 2 222 6.10 6.68 5 6 41 1 26 19 2 210 6.15 6.72 4 2 36 1 16 9 32 225 6.20 6.77 8 3 47 20 11 11 235 6.25 6.81 4 3 27 25 10 31 231 6.30 6.86 7 6 14 10 19 44 202 6.35 6.90 4 1 47 30 15 3 205 6.40 6.94 2 4 4 5 87 200 6.45 6.99 8 2 44 1 23 14 6 2 226 6.50 7.03 4 3 21 11 15 12 35 1 200 6.55 7.08 3 3 43 8 28 9 6 1 252 6.60 7.12 3 2 40 1 18 29 7 223 6.65 7.16 5 5 26 1 27 21 15 233 6.70 7.21 3 4 32 24 21 14 226 6.75 7.25 9 7 23 23 16 21 1 218 6.80 7.29 2 5 16 7 12 58 245 6.85 7.34 2 4 18 16 7 53 234 6.90 7.38 8 5 16 29 4 38 1 200 6.95 7.43 10 5 27 1 32 8 18 200 7.00 7.47 3 4 18 1 22 4 47 1 205 7.05 7.51 7 4 42 22 15 10 246 7.10 7.56 7 3 34 24 14 18 240 7.15 7.60 10 4 18 17 7 37 5 201 7.20 7.65 5 7 32 21 14 21 258 7.25 7.69 3 5 43 24 11 15 200 7.30 7.73 3 2 12 8 4 71 400 7.35 7.78 3 4 33 29 16 15 1 224 7.40 7.82 8 3 33 1 23 16 17 1 200 7.45 7.87 1 7 18 10 14 50 202 7.50 7.91 4 2 29 2 17 9 36 202 7.55 7.95 5 12 31 27 16 9 211 7.60 8.00 5 11 29 14 20 21 203 7.65 8.04 4 1 10 2 9 72 203 7.70 8.08 7 13 26 16 22 13 3 203 7.75 8.13 5 6 34 1 20 30 4 234 7.80 8.17 5 5 17 1 15 25 31 205 8.30 8.61 4 2 27 18 1 48 202 8.35 8.65 10 2 30 41 10 6 210 8.40 8.70 3 5 39 26 3 23 205 8.45 8.74 5 37 23 26 1 6 201 8.50 8.79 5 2 27 22 11 33 1 200 8.55 8.83 2 2 49 14 7 26 204 8.60 8.87 3 4 49 28 8 8 220 8.65 8.92 1 1 43 9 23 23 206 8.70 8.96 7 3 49 25 9 5 201 9.50 10.10 8 3 44 12 10 25 200 9.55 10.18 5 1 33 12 5 45 200 9.60 10.27 9 3 53 1 18 1 10 4 201 9.65 10.35 5 6 32 1 20 9 26 202 9.70 10.43 11 2 46 28 6 5 2 202 9.75 10.52 13 10 29 20 14 13 203 9.80 10.60 15 2 40 1 25 3 16 200 9.85 10.68 12 2 50 12 21 1 4 200 9.90 10.77 6 1 50 16 14 6 6 201 9.95 10.85 7 2 46 10 27 4 1 1 202 10.00 10.93 4 3 40 23 27 2 201 10.05 11.02 9 1 52 18 13 5 1 203 10.10 11.10 7 1 34 11 33 5 6 1 203 10.15 11.18 11 31 20 20 3 13 1 202 10.20 11.27 4 31 12 29 9 15 204 10.25 11.35 8 2 36 18 18 12 6 205 10.30 11.43 5 1 28 10 26 5 25 204 10.35 11.52 4 4 40 10 26 7 8 201 10.40 11.60 7 2 46 5 26 6 7 203 10.45 11.68 2 5 37 23 20 9 3 201 10.50 11.77 1 20 28 29 17 5 206 10.55 11.85 1 8 60 22 8 1 208 10.60 11.93 2 19 41 25 11 208 10.65 12.02 1 1 14 61 11 11 202 10.70 12.10 1 2 10 62 14 10 203 10.75 12.18 4 1 7 64 13 11 203 10.80 12.27 2 1 14 54 17 11 1 202 10.85 12.35 2 1 12 60 16 8 205 10.90 12.43 1 2 13 53 19 11 204 10.95 12.52 2 2 14 51 18 12 1 203 11.00 12.64 1 2 19 43 22 12 1 202 11.05 12.73 1 1 13 52 19 11 1 202 11.35 13.08 5 8 37 28 14 5 1 209 11.40 13.12 4 8 21 53 11 3 204 11.45 13.17 2 8 29 38 21 2 206 11.50 13.21 11 4 29 26 24 5 203 11.55 13.26 2 43 38 14 2 204 11.60 13.30 11 4 32 25 15 12 1 209 11.65 13.35 6 7 29 26 26 5 206 11.70 13.39 6 2 42 28 18 3 204 11.75 13.44 21 1 33 6 15 22 1 202 11.80 13.48 3 4 34 29 19 9 2 204 11.85 13.53 8 2 38 28 15 8 1 203 11.90 13.57 2 3 36 32 15 10 1 204 11.95 13.61 23 3 39 10 17 6 202 12.00 13.66 11 6 43 19 13 8 205 12.05 13.70 3 2 10 51 9 10 16 209 12.10 13.75 10 3 30 30 21 6 203 12.15 13.79 4 8 27 38 11 12 208 11.10 12.82 1 14 46 27 10 204 11.15 12.90 2 18 47 23 9 1 202 11.20 12.94 1 2 20 50 20 6 204 11.25 12.99 2 4 39 18 33 3 1 204 11.30 13.03 2 8 13 50 15 8 3 204 12.20 13.84 11 3 54 14 10 6 1 203 12.25 13.88 9 1 32 20 26 10 1 204 12.30 13.93 13 2 26 31 18 8 1 202 12.35 13.97 2 1 26 44 21 6 204 12.40 14.02 8 2 45 23 14 8 203 12.45 14.06 11 4 29 23 27 7 207 12.50 14.11 5 1 35 29 14 13 3 205 12.55 14.15 6 2 29 33 18 12 207 12.60 14.19 7 3 32 34 19 4 204 12.65 14.24 9 4 33 31 16 6 1 206 12.70 14.28 2 1 14 63 16 2 206 12.75 14.33 6 6 37 33 11 5 1 206 12.80 14.37 4 5 35 37 12 7 205 12.85 14.42 5 2 33 36 16 6 203 12.90 14.46 6 6 30 32 18 8 205 12.95 14.51 3 6 19 42 14 16 207 13.00 14.55 2 3 17 67 5 4 205 13.05 14.60 4 22 49 17 8 206 13.10 14.64 8 72 15 4 201 13.15 14.69 1 3 19 40 29 5 1 205 13.20 14.73 1 2 15 61 17 3 205 13.25 14.78 1 22 50 20 6 206 13.41 14.92 3 14 53 16 13 216 13.46 14.96 2 11 57 22 6 1 207 13.51 15.01 10 63 22 5 205 13.56 15.05 1 7 54 26 11 203 13.61 15.10 1 1 10 62 15 11 206 13.66 15.14 3 2 12 58 13 12 206 13.71 15.19 1 2 13 55 18 11 204 3. Silicoflagellates Baron et al. (2004) Table 4. Relative abundance of silicoflagellate taxa in samples studied from DSDP 480. See Table 3 for sample identification. Column 1: Depth m. Column 2: Age KYrBP Column 3: Dictyocha acueata Column 4: D. aff. D. aculeata Column 5: D.aspinosa Column 6: D.calida Column 7: D.calida ampliata Column 8: D.perlaevis Column 9: D.stapedia Column 10: Octactis pulchra (lrg) Column 11: Octactis pulchra (med) Column 12: Octactis pulchra (small) Column 13: Octactis pulchra (thick) Column 14: Number counted Depth Age D.acu. D.aff.D D.asp. D.cal. D.c-am D.perl. D.stap. O.p-lg O.p-med O.p-sm O.p-thk Num.counted 0.05 1.37 6 3 2 6 8 5 20 45 300 0.10 1.42 8 1 2 2 11 17 4 13 43 1 200 0.20 1.51 2 4 10 1 5 7 5 16 46 4 200 0.25 1.55 2 1 1 1 9 17 7 18 46 2 200 0.35 1.64 3 1 2 3 12 15 8 20 34 4 200 0.45 1.72 5 2 1 17 9 5 21 40 3 200 0.50 1.77 5 5 12 6 3 29 41 2 200 0.65 1.90 3 1 1 13 10 6 33 27 6 300 1.05 2.25 2 2 2 6 8 12 14 53 2 200 1.10 2.29 8 5 2 2 14 9 10 9 41 2 200 1.15 2.34 1 1 3 1 20 30 3 14 24 1 300 1.20 2.38 3 3 4 3 8 31 5 22 21 3 200 1.30 2.47 6 10 5 8 17 8 12 32 1 300 1.40 2.56 1 3 1 7 20 4 8 56 2 200 1.49 2.64 4 7 2 23 7 7 22 27 1 200 1.65 2.78 2 2 1 11 21 11 20 32 3 200 1.75 2.87 1 5 1 7 1 24 34 4 10 12 1 300 1.80 2.91 6 3 2 16 29 5 23 15 2 300 1.90 3.00 2 2 1 13 32 6 16 29 1 300 2.00 3.08 4 3 1 25 19 4 19 25 200 2.05 3.13 4 2 7 2 9 26 5 23 22 1 200 2.15 3.22 3 1 3 1 15 35 6 17 20 350 2.20 3.26 1 5 1 1 23 40 4 12 11 1 300 2.25 3.30 3 1 1 2 13 42 4 23 13 300 2.30 3.35 2 1 10 57 6 12 11 1 300 2.35 3.39 1 2 1 14 57 2 14 9 1 300 2.40 3.44 2 2 1 12 52 3 9 21 1 200 2.45 3.48 3 3 1 16 41 13 6 16 2 200 2.50 3.52 4 3 4 2 12 56 4 5 11 1 200 2.55 3.57 1 1 4 7 52 8 13 15 2 200 2.59 3.60 2 1 1 12 45 8 13 21 1 200 2.65 3.65 1 1 3 1 13 42 4 9 9 2 200 2.75 3.74 3 1 3 8 41 5 15 23 2 200 2.80 3.79 3 2 4 6 61 3 15 8 200 2.85 3.83 1 6 4 3 9 57 5 9 7 1 200 3.05 4.01 3 4 1 8 48 3 17 15 2 200 3.10 4.05 4 1 4 1 6 59 6 13 9 1 200 3.15 4.09 1 3 1 5 39 6 10 32 1 300 3.20 4.14 1 2 1 5 47 4 17 24 1 300 3.25 4.18 1 1 1 10 5 54 6 12 13 1 200 3.35 4.27 2 4 2 1 13 50 3 9 17 1 300 3.45 4.36 1 2 1 6 59 7 4 19 1 300 3.50 4.40 4 1 8 38 13 17 19 1 300 3.60 4.49 3 3 4 4 62 4 8 14 1 200 3.65 4.53 1 3 6 2 2 35 3 3 47 200 3.70 4.58 1 1 1 5 1 11 62 3 7 11 200 3.75 4.62 3 1 10 34 1 6 47 200 4.75 5.50 15 3 1 9 28 9 17 17 3 200 4.80 5.54 1 11 1 3 2 10 15 12 10 32 3 300 4.85 5.58 4 1 6 3 11 50 6 8 12 1 200 4.90 5.63 2 1 12 37 3 16 30 1 200 4.95 5.67 1 1 2 1 7 57 4 11 15 1 300 5.00 5.72 7 2 1 4 58 5 13 11 300 5.05 5.76 1 1 4 2 2 51 13 7 19 1 200 5.10 5.80 1 3 1 5 58 4 12 16 200 5.15 5.85 4 2 1 11 58 4 8 11 1 200 5.20 5.89 1 1 1 1 2 4 72 3 9 9 200 5.25 5.94 1 1 3 2 9 47 7 5 26 1 300 5.30 5.98 2 2 3 47 2 11 32 100 5.35 6.02 1 1 4 1 6 58 4 13 13 300 5.40 6.07 1 3 5 2 68 1 8 9 200 5.45 6.11 1 1 2 6 55 5 21 7 300 5.55 6.20 2 12 58 3 13 13 200 5.60 6.24 1 1 5 51 5 14 26 200 5.65 6.29 1 1 1 1 7 61 3 5 22 300 5.70 6.33 2 2 6 61 7 11 13 200 5.75 6.37 1 1 8 57 2 18 12 300 6.05 6.64 6 2 1 9 51 11 12 11 200 6.10 6.68 1 1 2 4 2 5 57 8 13 7 300 6.15 6.72 1 2 2 1 3 60 3 7 23 200 6.20 6.77 1 8 51 10 12 17 200 6.25 6.81 2 1 1 7 49 6 19 16 300 6.30 6.86 1 1 3 64 6 11 15 200 6.35 6.90 1 3 43 2 17 33 300 6.45 6.99 1 1 3 45 7 23 21 300 6.50 7.03 1 1 1 55 5 10 27 200 6.55 7.08 2 1 3 1 6 50 2 22 13 200 6.75 7.25 1 1 1 1 1 56 3 14 19 200 6.85 7.34 2 1 2 49 4 19 26 200 7.05 7.51 1 3 1 1 50 4 15 25 200 7.20 7.65 1 1 2 53 8 20 15 200 7.25 7.69 1 1 3 76 3 8 10 200 7.30 7.73 1 2 3 1 1 1 28 2 17 44 200 7.35 7.78 1 1 4 78 4 10 3 200 7.40 7.82 5 1 1 56 3 23 12 200 7.45 7.87 3 3 1 76 2 6 12 200 7.50 7.91 1 5 3 2 67 3 16 5 300 7.70 8.08 1 1 5 62 4 16 8 300 7.75 8.13 1 1 3 73 4 10 10 200 7.80 8.17 2 3 1 4 71 6 9 6 200 8.05 8.39 1 2 1 2 64 4 15 9 200 8.15 8.48 1 1 1 3 78 5 8 5 200 8.25 8.57 1 4 1 1 4 71 5 9 4 200 8.40 8.70 1 1 1 4 64 6 14 8 200 8.50 8.79 3 73 4 12 9 200 8.55 8.83 2 2 5 2 9 45 5 15 16 200 8.60 8.87 1 1 9 67 9 11 2 210 8.65 8.92 1 2 1 3 84 4 6 3 200 8.70 8.96 1 1 3 3 73 6 7 9 200 9.50 10.10 2 11 58 4 15 10 200 9.55 10.18 1 2 9 49 2 18 20 200 9.60 10.27 3 1 5 13 41 4 16 20 300 9.70 10.43 1 8 28 3 28 28 200 9.90 10.77 2 1 7 21 7 24 39 300 9.95 10.85 1 4 61 4 13 17 300 10.00 10.93 2 11 60 5 11 10 200 10.05 11.02 1 1 6 43 3 30 18 200 10.10 11.10 1 1 1 3 43 1 12 36 300 10.20 11.27 2 6 57 4 12 21 300 10.25 11.35 3 1 8 38 3 17 31 200 10.30 11.43 1 25 6 23 1 2 15 28 100 10.35 11.52 1 2 3 1 8 35 3 13 38 200 10.40 11.60 22 1 9 22 1 28 17 100 10.45 11.68 53 1 6 8 1 2 10 19 200 10.55 11.85 90 6 2 5 1 1 300 10.60 11.93 36 34 14 2 6 6 200 10.65 12.02 3 1 39 16 1 3 12 24 100 10.70 12.10 2 49 16 2 10 19 200 10.75 12.18 5 49 16 2 16 11 100 10.80 12.27 1 2 28 20 1 3 26 22 200 10.85 12.35 4 2 1 1 36 22 3 19 16 200 10.90 12.43 3 43 24 1 13 16 100 10.95 12.52 1 1 1 29 28 2 16 20 100 11.00 12.64 1 37 18 3 17 21 100 11.05 12.73 2 1 37 24 15 17 100 11.10 12.82 1 2 41 22 1 13 21 200 11.15 12.90 1 2 2 31 35 2 10 15 200 11.20 12.94 1 1 23 25 4 18 22 300 11.30 13.03 1 1 22 31 2 20 24 200 11.40 13.12 20 20 2 27 30 300 11.45 13.16 16 31 2 23 35 200 11.50 13.21 1 16 22 2 20 38 300 11.55 13.25 1 11 13 1 17 62 300 11.60 13.29 3 14 3 20 61 200 11.65 13.34 5 16 1 2 20 56 200 11.70 13.38 18 4 2 27 46 300 11.75 13.43 1 10 8 1 16 66 200 11.80 13.47 5 1 1 18 17 3 17 40 300 11.85 13.51 6 1 1 18 18 2 20 33 300 11.90 13.56 1 16 9 1 1 20 54 200 11.95 13.60 1 7 19 2 23 46 200 12.00 13.65 1 1 13 6 1 1 21 59 300 12.05 13.69 1 16 10 1 3 28 40 330 12.10 13.73 1 16 10 1 18 53 300 12.15 13.78 4 14 23 1 27 32 200 12.20 13.82 5 1 12 7 1 3 33 44 300 12.25 13.86 1 1 6 29 7 29 28 200 12.30 13.91 2 1 11 18 1 3 26 39 200 12.35 13.95 1 9 9 1 35 45 300 12.40 14.00 2 2 12 9 3 1 30 43 200 12.45 14.04 1 1 11 4 7 2 44 31 300 12.50 14.08 2 2 12 12 2 2 31 30 330 12.55 14.13 1 1 11 15 1 2 26 45 200 12.60 14.17 1 13 8 1 3 33 42 200 12.65 14.22 6 11 2 5 28 47 200 12.70 14.26 4 1 18 17 4 32 24 200 12.75 14.30 3 1 24 11 2 1 34 25 200 12.80 14.35 1 9 9 10 7 28 36 200 12.90 14.44 1 14 12 6 2 44 21 300 12.95 14.48 1 1 22 8 18 4 25 18 300 13.00 14.52 22 8 3 1 33 32 200 13.05 14.57 2 7 1 35 14 7 1 19 13 200 13.10 14.61 1 52 8 4 3 16 16 100 13.15 14.65 4 20 11 21 3 20 17 300 13.20 14.70 1 67 8 5 8 8 100 13.25 14.74 6 1 43 9 12 3 14 9 100 13.41 14.88 40 3 11 4 30 22 300 13.46 14.93 6 79 4 2 3 7 200 13.51 14.97 1 4 57 16 2 1 8 5 100 13.56 15.01 60 4 6 2 15 12 100 13.61 15.06 1 46 11 10 3 11 18 100 13.66 15.10 2 51 9 13 2 7 16 100 13.71 15.15 54 7 16 11 10 100