Radiolarian faunal turnover across the Oligocene/Miocene boundary in the equatorial Pacific Ocean ...

• Main Authors: Kamikuri, Shin-Ichi, Nishi, Hiroshi, Moore, Theodore C, Nigrini, Catherine A, Motoyama, Isao
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2005
• Subjects: Drilling/drill rig; Leg199; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctic
• Online Access: https://dx.doi.org/10.1594/pangaea.685594; https://doi.pangaea.de/10.1594/PANGAEA.685594

The global warming trend of the latest Oligocene was interrupted by several cooling events associated with Antarctic glaciations. These cooling events affected surface water productivity and plankton assemblages. Well-preserved radiolarians were obtained from upper Oligocene to lower Miocene sediments at Ocean Drilling Program (ODP) Leg 199 Sites 1218 and 1219 in the equatorial Pacific, and 110 radiolarian species were identified.Four episodes of significant radiolarian faunal changes were identified: middle late Oligocene (27.5 to 27.3 Ma), latest Oligocene (24.4 Ma), earliest Miocene (23.3 Ma), and middle early Miocene (21.6 Ma). These four episodes approximately coincide with increases and decreases of biogenic silica accumulation rates and increases in delta18O values coded as „Oi“ and „Mi“ events. These data indicate that Antarctic glaciations were associated with change of siliceous sedimentation patterns and faunal changes in the equatorial Pacific.Radiolarian fauna was divided into three assemblages ... : Supplement to: Kamikuri, Shin-Ichi; Nishi, Hiroshi; Moore, Theodore C; Nigrini, Catherine A; Motoyama, Isao (2005): Radiolarian faunal turnover across the Oligocene/Miocene boundary in the equatorial Pacific Ocean. Marine Micropaleontology, 57(3-4), 74-96 ...