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