Barke, Judith; van der Burgh, Johan; van Konijnenburg-van Cittert, Johanna H A; Collinson, Margaret E; Pearce, Martin A; Bujak, Jonathan; Heilmann-Clausen, Claus; Speelman, Eveline N; van Kempen, Monique M L; Reichart, Gert-Jan; Lotter, André F; Brinkhuis, Henk (2012): Freshwater fern Azolla in and around Arctic and Nordic seas. doi:10.1594/PANGAEA.787105, Supplement to: Barke, J et al. (2012): Coeval Eocene blooms of the freshwater fern Azolla in and around Arctic and Nordic seas. Palaeogeography, Palaeoclimatology, Palaeoecology, 337-338, 108-119, doi:10.1016/j.palaeo.2012.04.002
Always quote above citation when using data! You can download the citation in several formats below.
For a short time interval (c. 1.2 Myr) during the early middle Eocene (~49 Myr), the central Arctic Ocean was episodically densely covered by the freshwater fern Azolla, implying sustained freshening of surface waters. Coeval Azolla fossils in neighboring Nordic seas were thought to have been sourced from the Arctic. The recognition of a different Azolla species in the North Sea raised doubts about this hypothesis. Here we show that no less than five Azolla species had coeval blooms and spread in the Arctic and NW European regions. A likely trigger for these unexpected Azolla blooms is high precipitation prevailing by the end of the warmest climates of the Early Eocene Climatic Optimum (EECO).
Median Latitude: 78.658059 * Median Longitude: 111.611312 * South-bound Latitude: 55.554690 * West-bound Longitude: 1.033300 * North-bound Latitude: 87.866580 * East-bound Longitude: -135.415000
Date/Time Start: 1985-08-03T06:07:00 * Date/Time End: 2004-08-27T00:00:00
Datasets listed in this Collection
- Barke, J; van der Burgh, J; van Konijnenburg-van Cittert, JHA et al. (2012): (Table 3) Relative abundance of Azolla spp., peridinoid dinocysts, gonyaulacoid dinocysts, non-saccate pollen, bisaccate pollen and spores from the Lomonosov Ridge during different Arctic coring expeditions. doi:10.1594/PANGAEA.787102