Indonesian Gateway DSDP214 Pliocene Paired d18O and Mg/Ca Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Indonesian Gateway DSDP214 Pliocene Paired d18O and Mg/Ca Data LAST UPDATE: 5/2009 (Original receipt by WDC Paleo) CONTRIBUTOR: Cyrus Karas, IFM-GEOMAR. IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-055 WDC PALEO CONTRIBUTION SERIES CITATION: Karas, C., et al. 2009. Indonesian Gateway DSDP214 Pliocene Paired d18O and Mg/Ca Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-055. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Karas, C., D. Nürnberg, A.K. Gupta, R. Tiedemann, K. Mohan, and T. Bickert. 2009. Mid-Pliocene climate change amplified by a switch in Indonesian subsurface throughflow. Nature Geoscience, DOI: 10.1038/NGEO520, published online 17 May 2009. ABSTRACT: The tectonically driven closure of tropical seaways during the Pliocene epoch (~5–2 million years (Myr) ago) altered ocean circulation and affected the evolution of climate. Plate tectonic reconstructions show that the main reorganization of one such seaway, the Indonesian Gateway, occurred between 4 and 3 Myr ago. Model simulations have suggested that this would have triggered a switch in the source of waters feeding the Indonesian throughflow into the Indian Ocean, from the warm salty waters of the South Pacific Ocean to the cool and relatively fresh waters of the North Pacific Ocean. Here we use paired measurements of the d18O and Mg/Ca ratios of planktonic foraminifera to reconstruct the thermal structure of the eastern tropical Indian Ocean from 5.5 to 2 Myr ago. We find that sea surface conditions remained relatively stable throughout the interval, whereas subsurface waters freshened and cooled by about 4C between 3.5 and 2.95 Myr ago. We suggest that the restriction of the Indonesian Gateway led to the cooling and shoaling of the thermocline in the tropical Indian Ocean. We conclude that this tectonic reorganization contributed to the global shoaling of the thermocline recorded during the Pliocene epoch, possibly contributing to the development of the equatorial eastern Pacific cold tongue. GEOGRAPHIC REGION: Tropical East Indian Ocean (Ninety East Ridge) PERIOD OF RECORD: 5.5 to 2 MyrBP FUNDING SOURCES: German Science Foundation (DFG) within project Nu60/17-1. K.M. was supported by an IIT Kharagpur fellowship. DESCRIPTION: Combined planktonic foraminiferal Mg/Ca and d18O data from the tropical eastern Indian Ocean, Deep Sea Drilling Project (DSDP) Site 214, spanning the time period from 5.5 to 2 Myr ago. Site 214 is at a key location, as the surface waters there record the conditions of the Indian-Pacific warm pool, whereas the subsurface waters belong to the cold and fresh Australasian Mediterranean water, which originates from the Indonesian throughflow area. We selected surface-dwelling planktonic foraminifera Globigerinoides ruber and Globigerinoides sacculifer, deep mixed-layer species Globoquadrina venezuelana and deep dwelling Globorotalia crassaformis to reconstruct oceanographic changes at different depth levels. DSDP Site 214: 11°20.21'S, 88°43.08'E, 1,665m water depth DATA: 1. Karas et al. 2009 DSDP214 paired d18O Mg/Ca, planktonic and mixed layer Column 1: Depth (mbsf) Column 2: Age (Ma) Column 3: d18O G. ruber (per mil) Column 4: d18O G. sacculifer (per mil) Column 5: d18O G. crassaformis (per mil) Column 6: Mg/Ca G. ruber (mmol/mol) Column 7: Mg/Ca G. sacculifer (mmol/mol) Column 8: Mg/Ca G. venezuelana (mmol/mol) Column 9: Mg/Ca G. crassaformis (mmol/mol) Depth Age d18OG.rub d18OG.sac d18OG.cra Mg/Ca rub Mg/Ca sac Mg/Ca ven Mg/Ca cra 22.6 2.013 -1.275 1.643 3.58 1.56 22.7 2.023 -1.336 1.796 3.54 1.60 22.8 2.034 -1.270 1.737 3.56 1.73 22.9 2.045 -1.133 1.592 3.67 1.90 23.0 2.056 -1.534 1.291 3.70 1.66 23.2 2.072 -1.484 1.720 3.87 1.75 23.3 2.083 -0.987 1.659 3.65 1.73 23.4 2.094 -1.062 1.784 3.63 1.46 23.5 2.105 -1.477 0.753 3.81 1.67 23.6 2.115 -1.164 0.953 3.66 1.73 23.7 2.126 -1.443 1.593 3.66 1.68 23.8 2.137 -1.414 1.594 3.66 1.91 23.9 2.148 -1.241 1.695 3.75 1.97 24.0 2.159 -1.317 1.960 3.56 1.84 24.1 2.175 -1.474 1.267 3.79 1.74 24.3 2.197 -1.554 1.479 3.83 1.80 24.5 2.213 -1.735 1.112 4.03 1.67 24.6 2.229 -1.407 1.785 3.95 1.57 24.8 2.245 -1.217 1.425 3.72 1.68 25.0 2.253 -1.534 1.377 3.66 1.81 25.4 2.273 -1.704 1.453 3.86 1.64 25.6 2.287 -1.373 1.667 3.59 1.71 26.0 2.324 -1.304 1.218 3.79 1.75 26.2 2.342 -1.622 0.721 3.79 26.4 2.360 -1.465 1.581 4.01 1.65 26.7 2.374 -1.806 0.823 3.81 1.90 27.0 2.387 -1.450 1.073 3.76 1.74 27.3 2.402 -1.337 1.386 3.83 1.72 27.7 2.420 -1.556 1.118 3.59 1.63 28.0 2.439 -1.452 1.512 3.76 1.66 29.0 2.507 -1.354 1.161 3.83 1.58 29.3 2.528 -1.415 0.880 3.60 1.77 29.6 2.548 -1.415 1.488 3.65 1.90 29.9 2.568 -1.251 1.468 3.62 1.75 30.3 2.594 -1.412 1.635 3.70 1.91 30.7 2.622 -1.490 1.577 3.64 1.76 30.9 2.636 -1.329 1.678 3.54 1.79 31.3 2.663 -1.643 1.577 3.71 1.78 31.8 2.680 -1.736 3.67 1.80 32.3 2.698 -1.171 1.737 3.65 1.64 32.6 2.708 -1.148 1.869 3.57 1.60 33.0 2.723 -1.453 1.668 3.50 33.5 2.741 -1.700 1.853 3.64 1.59 33.8 2.756 -1.835 1.417 3.82 1.79 34.1 2.780 -1.535 1.025 3.62 1.79 34.5 2.811 -1.664 1.421 3.55 1.62 35.0 2.848 -2.001 1.132 3.76 1.74 35.3 2.866 -1.694 1.779 3.58 1.79 35.6 2.889 -1.664 1.439 3.68 1.91 36.0 2.916 -1.773 1.692 3.66 1.74 36.4 2.943 -1.861 1.415 3.80 1.85 36.6 2.952 -1.615 1.465 3.64 1.79 37.3 2.967 -1.588 1.410 3.66 1.76 38.0 2.983 -1.786 1.491 3.59 2.08 39.0 3.005 -1.430 1.719 3.52 1.65 40.0 3.076 -1.722 1.755 3.75 1.86 41.0 3.157 -1.576 1.345 3.88 2.38 42.0 3.205 -1.652 1.495 3.82 2.11 43.0 3.250 -1.607 1.742 3.91 2.26 44.0 3.295 -1.616 0.891 3.65 2.46 45.0 3.367 -1.884 0.817 3.52 1.92 46.0 3.439 -1.961 0.565 4.05 2.15 46.8 3.490 -1.764 0.784 3.76 2.02 48.0 3.533 -1.716 0.999 3.65 48.6 3.552 -1.195 0.504 3.70 2.36 49.0 3.566 -1.588 0.515 3.755 3.51 49.5 3.584 -1.771 3.914 3.57 50.0 3.603 -1.096 1.003 3.984 50.5 3.618 -1.628 3.917 3.41 51.0 3.636 -1.267 0.875 3.759 2.36 51.5 3.653 -1.424 3.982 52.0 3.670 -1.709 3.847 52.5 3.698 -1.599 3.918 53.0 3.726 -1.346 3.769 3.58 53.5 3.749 -1.512 4.181 57.5 3.961 -1.094 4.067 3.29 58.0 3.988 -1.288 4.047 3.60 58.5 4.015 -1.284 0.976 3.967 3.60 2.23 58.9 4.029 -1.045 3.859 3.27 59.5 4.049 -1.304 0.868 3.627 3.42 2.43 60.0 4.067 -1.622 4.023 3.76 60.5 4.083 -1.479 0.955 3.845 2.75 61.0 4.101 -1.345 3.865 61.5 4.119 -1.394 0.917 3.653 2.27 62.0 4.136 -1.438 4.023 62.5 4.155 -1.591 1.147 4.261 2.37 63.0 4.205 -1.237 4.106 3.57 63.5 4.254 -1.236 1.222 3.804 1.98 64.0 4.311 -1.130 3.931 3.59 64.5 4.329 -1.298 1.094 3.655 3.75 2.12 64.8 4.342 -1.500 3.892 3.56 65.5 4.371 -1.287 1.146 3.39 2.13 66.0 4.392 -1.052 3.740 3.12 66.5 4.410 -1.583 3.460 3.56 67.0 4.427 -0.687 3.501 3.45 68.0 4.460 -1.283 3.497 3.53 69.0 4.494 -1.121 3.744 3.39 70.1 4.529 -1.189 3.634 3.46 71.0 4.559 -1.023 3.453 3.48 72.0 4.594 -1.017 3.677 3.71 76.5 4.742 -1.160 3.993 3.53 77.0 4.758 -0.762 3.832 3.67 78.0 4.792 -1.061 3.535 3.21 79.0 4.824 -1.236 3.725 3.55 80.0 4.857 -1.297 3.814 3.38 81.0 4.891 -1.149 3.618 3.34 82.0 4.924 -1.008 3.407 2.88 83.0 4.957 -1.140 3.634 3.24 84.0 4.990 -1.201 3.698 3.15 85.0 5.023 -1.024 3.792 3.40 86.5 5.060 -1.008 3.649 3.18 87.4 5.074 -1.076 4.058 3.32 88.5 5.090 -1.039 3.696 3.02 89.5 5.103 -1.226 3.557 3.18 90.5 5.118 -0.872 3.761 3.25 91.5 5.134 -1.442 3.768 3.27 92.5 5.147 -1.121 3.470 2.98 93.5 5.162 -1.038 3.629 3.16 94.5 5.177 -1.305 3.424 3.10 96.0 5.199 -1.154 3.538 2.98 96.3 5.202 -1.089 3.305 3.00 97.2 5.217 -1.253 3.405 2.97 98.2 5.231 -1.064 3.582 3.32 99.2 5.246 -0.855 3.498 3.04 100.2 5.260 -1.010 3.282 2.95 101.2 5.275 -1.003 3.344 2.92 103.2 5.304 -1.178 3.492 105.0 5.330 -1.109 3.719 107.0 5.359 -1.351 3.791 3.18 108.9 5.387 -0.977 3.565 2.89 114.0 5.461 -0.832 3.596 3.08 2. Karas et al. 2009 DSDP214 benthic d18O Column 1: Depth (mbsf) Column 2: Age (Ma) Column 3: d18O benthos (C. wuellerstorfi) Depth Age d18O C.wuell 24.1 2.175 2.665 24.2 2.186 2.730 24.3 2.197 2.697 24.4 2.208 2.741 24.5 2.213 2.620 24.5 2.218 2.922 24.6 2.229 2.653 24.7 2.240 2.945 24.8 2.245 2.718 24.9 2.250 2.558 25.0 2.253 2.703 25.3 2.269 2.626 25.4 2.273 2.662 25.5 2.278 2.936 25.6 2.287 2.650 25.8 2.305 2.636 26.0 2.324 2.691 26.0 2.325 2.703 26.1 2.333 2.835 26.2 2.342 2.735 26.3 2.351 2.722 26.4 2.360 2.886 26.5 2.364 2.778 26.7 2.374 2.705 26.9 2.383 2.778 27.0 2.387 2.743 27.1 2.392 2.684 27.3 2.402 2.596 27.5 2.411 2.684 27.7 2.420 2.471 27.9 2.434 2.613 28.0 2.439 2.974 28.8 2.494 2.699 29.0 2.507 2.477 29.2 2.521 3.057 29.3 2.528 2.823 29.4 2.534 2.675 29.6 2.548 2.624 29.8 2.561 2.400 29.9 2.568 2.759 30.1 2.582 2.445 30.3 2.594 2.700 30.5 2.609 2.702 30.7 2.622 2.817 30.8 2.628 2.662 30.9 2.636 2.804 31.1 2.650 2.869 31.3 2.663 2.378 31.5 2.670 2.628 31.8 2.680 2.597 32.0 2.687 2.759 32.3 2.698 2.834 32.4 2.701 2.932 32.6 2.708 2.930 32.8 2.715 2.841 33.0 2.723 2.868 33.3 2.733 2.784 33.5 2.741 2.665 33.7 2.748 2.581 33.8 2.756 2.654 33.9 2.764 2.506 34.1 2.780 2.680 34.3 2.795 2.629 34.5 2.811 2.655 34.8 2.833 2.510 35.0 2.848 2.555 35.2 2.862 2.685 35.3 2.866 2.696 35.4 2.875 2.657 35.6 2.889 2.612 35.8 2.902 2.624 36.0 2.916 2.623 36.3 2.934 2.497 36.4 2.943 2.587 36.5 2.950 2.438 36.6 2.952 2.599 36.8 2.956 2.530 37.3 2.967 2.626 37.8 2.978 2.628 38.0 2.983 2.629 38.5 2.994 2.644 39.0 3.005 2.578 39.5 3.015 2.707 40.0 3.076 2.485 40.5 3.135 2.591 41.0 3.157 2.510 41.5 3.181 2.476 42.0 3.205 2.436 42.5 3.226 2.282 43.0 3.250 2.455 43.5 3.273 2.566 44.0 3.295 2.658 44.5 3.332 2.529 45.0 3.367 2.375 45.5 3.399 2.529 46.0 3.439 2.424 46.5 3.472 2.090 46.8 3.490 2.057 48.0 3.533 2.287 48.6 3.552 2.357 49.0 3.566 2.202 49.5 3.584 2.177 50.0 3.603 2.216 50.5 3.618 2.180 51.0 3.636 2.265 51.5 3.653 2.298 52.0 3.670 2.353 52.5 3.698 2.264 53.0 3.726 2.130 53.5 3.749 2.024 57.5 3.961 2.234 58.0 3.988 2.170 58.5 4.015 2.091 58.9 4.029 2.315 59.5 4.049 2.384 60.0 4.067 2.241 60.5 4.083 2.320 61.0 4.101 2.206 61.5 4.119 2.263 62.0 4.136 2.094 62.5 4.155 2.328 63.0 4.205 2.151 63.5 4.254 2.327 64.0 4.311 2.295 64.5 4.329 2.239 64.8 4.342 2.364 65.5 4.371 2.207 66.0 4.392 2.288 66.5 4.410 2.229