Radiolarian assemblages of the late Neogene North Pacific ...

• Main Authors: Kamikuri, Shin-Ichi, Nishi, Hiroshi, Motoyama, Isao
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2007
• Subjects: Composite Core; Drilling/drill rig; Leg145; Leg186; Joides Resolution; Ocean Drilling Program ODP; Pacific; Subarctic
• Online Access: https://dx.doi.org/10.1594/pangaea.693841; https://doi.pangaea.de/10.1594/PANGAEA.693841

Radiolarian census and abundance data were collected from three deep-sea cores drilled by the Ocean Drilling Program Sites 884, 887 and 1151 to investigate patterns of ecologic changes in space and time during the last 16 million years for the mid-latitude to subarctic North Pacific. High concentrations of radiolarians occurred between 9.0 and 2.7 Ma. Radiolarian species richness was highest in the early middle Miocene at each site and gradually decreased up to about 7 Ma, coinciding with a well-established global cooling trend. A degree of overlap index calculated for radiolarian assemblages revealed 11 faunal change events, of which 8 corresponded to global cooling events and expansions of polar ice sheets. Three of the faunal change events were observed within the peak of radiolarian accumulation rate and were ascribed to changes in primary productivity in the North Pacific rather than global climatic changes.Our assemblage analyses revealed that north–south differentiation in radiolarian assemblages in ... : Supplement to: Kamikuri, Shin-Ichi; Nishi, Hiroshi; Motoyama, Isao (2007): Effects of late Neogene climatic cooling on North Pacific radiolarian assemblages and oceanographic conditions. Palaeogeography, Palaeoclimatology, Palaeoecology, 249(3-4), 370-392 ...