Romero, Oscar E (2006): Valve concentration of Ethmodiscus sp. and carbon in sediment core GeoB3801-6 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.327024, Supplement to: Romero, Oscar E; Schmieder, Frank (2006): Occurrence of thick Ethmodiscus oozes associated with a terminal Mid-Pleistocene Transition event in the oligotrophic subtropical South Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology, 235(4), 321-329, https://doi.org/10.1016/j.palaeo.2005.10.026
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Abstract:
Within generally calcareous sediment sequences, layers of variable thickness of the giant diatom Ethmodiscus were found in five cores recovered in the Subtropical South Atlantic between 23° and 33°S from both sides of the Mid-Atlantic Ridge. Two types of oozes occur: (almost) monospecific layers of Ethmodiscus and layers dominated by Ethmodiscus, with several accompanying tropical/subtropical, oligotrophic-water diatoms. The two thickest Ethmodiscus layers occur in GeoB3801-6 around 29°S, and accumulated during late MIS 14 and MIS 12, respectively. Downcore concentrations of Ethmodiscus valves range between 3.4 10 4 and 2.3 10 7 valves g -1. We discuss the ooze formation in the context of migration of frontal systems and changes in the thermohaline circulation. The occurrence of Ethmodiscus oozes in sediments underlying the present-day pelagic, low-nutrient waters is associated with a terminal event of the Mid-Pleistocene Transition at around 530 ka, when the ocean circulation rearranged after a period of reduced NADW production.
Project(s):
Coverage:
Latitude: -29.511667 * Longitude: -8.305000
Date/Time Start: 1996-02-26T00:00:00 * Date/Time End: 1996-02-26T00:00:00
Minimum DEPTH, sediment/rock: 5.10 m * Maximum DEPTH, sediment/rock: 7.98 m
Event(s):
GeoB3801-6 * Latitude: -29.511667 * Longitude: -8.305000 * Date/Time: 1996-02-26T00:00:00 * Elevation: -4546.0 m * Recovery: 9.37 m * Location: Mid Atlantic Ridge * Campaign: M34/3 * Basis: Meteor (1986) * Method/Device: Gravity corer (Kiel type) (SL) * Comment: Geology
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | DEPTH, sediment/rock | Depth sed | m | Geocode | ||
| 2 | Diatoms, total, per unit sediment mass | TDA/sed | 106 #/g | Romero, Oscar E | Counting, diatoms | Ethmodiscus sp. |
| 3 | Calcium carbonate | CaCO3 | % | Romero, Oscar E | Calculated, CaCO3=(TC-TOC)*8.333 | |
| 4 | Carbon, organic, total | TOC | % | Romero, Oscar E | Element analyser CHN-O Rapid, Heraeus |
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
120 data points
Data
| 1 Depth sed [m] | 2 TDA/sed [106 #/g] | 3 CaCO3 [%] | 4 TOC [%] |
|---|---|---|---|
| 5.10 | 0.015829 | ||
| 5.15 | 0.088516 | ||
| 5.18 | 0.364336 | 73.8 | 8.96 |
| 5.23 | 0.225341 | 68.1 | 8.28 |
| 5.28 | 0.097695 | 76.8 | 9.31 |
| 5.33 | 0.004100 | 91.0 | 10.98 |
| 5.38 | 0.027280 | 86.4 | 10.45 |
| 5.43 | 0.002266 | 88.7 | 10.71 |
| 5.48 | 0.023072 | 88.9 | 10.74 |
| 5.68 | 0.025070 | 81.2 | 9.84 |
| 5.78 | 0.000325 | 72.6 | 8.94 |
| 5.88 | 0.015135 | 91.2 | 10.99 |
| 5.98 | 0.018626 | 94.3 | 11.36 |
| 6.28 | 0.003964 | 92.1 | 11.12 |
| 6.38 | 0.004281 | 94.2 | 11.34 |
| 6.43 | 0.009301 | 93.0 | 11.23 |
| 6.48 | 0.010297 | 91.0 | 11.00 |
| 6.53 | 0.344883 | 81.7 | 9.91 |
| 6.58 | 0.278978 | 87.7 | 10.61 |
| 6.63 | 0.098112 | 85.1 | 10.30 |
| 6.68 | 0.697972 | 30.0 | 3.69 |
| 6.70 | 1.150302 | ||
| 6.73 | 0.885367 | 39.2 | 4.81 |
| 6.78 | 1.145836 | 40.5 | 4.96 |
| 6.83 | 0.501183 | 25.0 | 3.10 |
| 6.88 | 1.429949 | 42.9 | 5.25 |
| 6.98 | 0.505850 | 29.2 | 3.59 |
| 7.08 | 0.734049 | 27.1 | 3.33 |
| 7.18 | 0.704687 | 49.0 | 5.99 |
| 7.23 | 0.399025 | 30.3 | 3.73 |
| 7.33 | 0.170438 | 23.9 | 2.95 |
| 7.38 | 0.415858 | 23.2 | 2.87 |
| 7.48 | 0.625600 | 32.3 | 3.97 |
| 7.53 | 0.066546 | 59.2 | 7.23 |
| 7.63 | 0.577032 | 35.8 | 4.42 |
| 7.68 | 0.560767 | 25.8 | 3.23 |
| 7.73 | 0.650626 | 52.4 | 6.41 |
| 7.78 | 0.900293 | 46.8 | 5.76 |
| 7.83 | 0.445830 | 51.1 | 6.31 |
| 7.88 | 0.751208 | 93.0 | 11.19 |
| 7.93 | 0.190663 | 52.9 | 6.51 |
| 7.98 | 0.003054 | 75.2 | 9.18 |