(Table 2) Similarity Indexes (Pearson's correlation coefficient) of the silicoflagellate assemblages of IODP Exp302 ...

• Main Authors: Onodera, Jonaotaro, Takahashi, Kozo, Jordan, Richard William
• Format: Dataset
• Language: English
• Published: PANGAEA 2010
• Subjects: Similarity index; Comment; Reference of data; Composite Core; Modern analog technique MAT; Exp302; CCGS Captain Molly Kool Vidar Viking; Integrated Ocean Drilling Program / International Ocean Discovery Program IODP; Arctic Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.733882; https://doi.pangaea.de/10.1594/PANGAEA.733882

The silicoflagellate and ebridian assemblages in early middle Eocene Arctic cores obtained by IODP Expedition 302 (ACEX) were studied in order to decipher the paleoceanography of the upper water column. The assemblages in Lithologic Unit 2 (49.7-45.1 Ma), one of the biosiliceous intervals, were usually endemic as compared to the assemblages that occurred outside of the Arctic Ocean. The presence of these endemic assemblages is probably due to a unique environmental setting, controlled by the degree of mixing between the low-salinity Arctic waters and relatively high salinity waters supplied from outside the Arctic Ocean, such as the Atlantic and possibly the Western Siberian Sea. Using the basin-to-basin fractionation model, the early middle Eocene Arctic Ocean corresponds to an estuarine circulation type, which includes the modern-day Black Sea. The abundant down-core occurrence of ebridians strongly suggests the past presence of low-salinity waters, and may indicate that low oxygen concentrations prevailed ... : From Onodera and Takahashi (submitted manuscript, 2008a). The calculation is based on binary data (presence or absence of each species). The italicized values represent the significant correlation coefficients (p < 0.05). ...