Middle Miocene stable carbon and oxygen isotope record of foraminifera of ODP Hole 120-747A ...

• Main Authors: Majewski, Wojciech, Bohaty, Steven M
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2010
• Subjects: Drilling/drill rig; Leg120; Joides Resolution; Ocean Drilling Program ODP; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.775084; https://doi.pangaea.de/10.1594/PANGAEA.775084

Paleoceanographic variability at southern high latitude Ocean Drilling Program (ODP) Site 747 was investigated in this study through the interval which spans the Middle Miocene Climate Transition (MMCT). Between 15.0 and 12.2 million years ago (Ma), foraminiferal d18O records derived from both benthic (Cibicidoides spp.) and planktonic taxa (Globorotalia praescitula and Globigerina bulloides) reveal a history of changes in water column thermal and salinity structure and a strong imprint of seasonality. Prior to the MMCT, in the interval between 14.35 and 13.9 Ma, G. bulloides displays relatively high d18O values similar to those of G. praescitula, interpreted to indicate weakening of the thermocline and/or increased seasonality with cooler early-spring and/or late-fall temperatures. Following this interval, G. bulloidesd18O values diverge significantly from benthic and G. praescitula values, with G. bulloides values remaining relatively low for at least 600 kyr following the benthic foraminiferal d18O shift ... : Supplement to: Majewski, Wojciech; Bohaty, Steven M (2010): Surface-water cooling and salinity decrease during the Middle Miocene climate transition at Southern Ocean ODP Site 747 (Kerguelen Plateau). Marine Micropaleontology, 74(1-2), 1-14 ...