Miocene Biomarker Temperature and CO2 Estimates from DSDP Site 94-608 ...

• Main Authors: Super, James R, Thomas, Ellen, Pagani, Mark, Huber, Matthew, O'Brien, Charlotte L, Hull, Pincelli M
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2018
• Subjects: Drilling/drill rig; Leg94; Glomar Challenger; Deep Sea Drilling Project DSDP; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.887725; https://doi.pangaea.de/10.1594/PANGAEA.887725

Climate proxies indicate coupling between changes in atmospheric pCO2, global temperatures and ice volume over much of the Cenozoic. Evidence has been presented for decoupling of these factors in the Miocene, though the cause of the apparent decoupling was uncertain. Here, we revisit Deep Sea Drilling Program (DSDP) Site 608 (24-9 Ma) in the North Atlantic, to provide improved constraints on sea surface temperatures (SSTs) using the TEX86 and Uk'37 proxies, and use these to recalculate atmospheric pCO2. From the Oligocene/Miocene boundary to the middle Miocene Climatic Optimum (MCO, ~23.03 to ~14.5 Ma), SSTs at Site 608 were upwards of 30°C, nearly 15 °C warmer than modern. During the Middle Miocene Climatic Transition (MMCT), starting at ~14.5 Ma, SSTs cooled by ~ 6 °C These lower SSTs persisted until the end of our record (9 Ma). Our organic proxy derived SST estimates are considerably higher than those previously calculated from planktonic foraminiferal oxygen isotope data, leading to reassessed pCO2 ... : Supplement to: Super, James R; Thomas, Ellen; Pagani, Mark; Huber, Matthew; O'Brien, Charlotte; Hull, Pincelli M (2018): North Atlantic temperature and pCO2 coupling in the early-middle Miocene. Geology, 46(6), 519-522 ...