Holbourn, Ann; Kuhnt, Wolfgang; Kochhann, Karlos G D; Andersen, Nils; Meier, K J Sebastian (2015): Stable isotope record, carbonate and organic carbon content of the Miocene section of IODP Site 321-U1337. PANGAEA, https://doi.org/10.1594/PANGAEA.839743, Supplement to: Holbourn, A et al. (2015): Global perturbation of the carbon cycle at the onset of the Miocene Climatic Optimum. Geology, 43(2), 123-126, https://doi.org/10.1130/G36317.1
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The Miocene Climatic Optimum (~17-14.7 Ma) represents one of several major interruptions in the long-term cooling trend of the past 50 million years. To date, the processes driving high-amplitude climate variability and sustaining global warmth during this remarkable interval remain highly enigmatic. We present high-resolution benthic foraminiferal and bulk carbonate stable isotope records in an exceptional, continuous, carbonate-rich sedimentary archive (Integrated Ocean Drilling Program Site U1337, eastern equatorial Pacific Ocean), which offer a new view of climate evolution over the onset of the Climatic Optimum. A sharp decline in d18O and d13C at ~16.9 Ma, contemporaneous with a massive increase in carbonate dissolution, demonstrates that abrupt warming was coupled to an intense perturbation of the carbon cycle. The rapid recovery in d13C at ~16.7 Ma, ~200 k.y. after the beginning of the MCO, marks the onset of the first carbon isotope maximum within the long-lasting "Monterey Excursion". These results lend support to the notion that atmospheric pCO2 variations drove profound changes in the global carbon reservoir through the Climatic Optimum, implying a delicate balance between changing CO2 fluxes, rates of silicate weathering and global carbon sequestration. Comparison with a high-resolution d13C record spanning the onset of the Cretaceous Oceanic Anoxic Event 1a (~120 Ma ago) reveals common forcing factors and climatic responses, providing a long-term perspective to understand climate-carbon cycle feedbacks during warmer periods of Earth's climate with markedly different atmospheric CO2 concentrations.
Latitude: 3.833000 * Longitude: -123.206000
Datasets listed in this publication series
- Holbourn, A; Kuhnt, W; Kochhann, KGD et al. (2015): Carbonate and TOC content in the Miocene section of IODP Site 321-U1337. https://doi.org/10.1594/PANGAEA.839742
- Holbourn, A; Kuhnt, W; Kochhann, KGD et al. (2015): Miocene stable isotope record of benthic foraminifera from IODP Site 321-U1337. https://doi.org/10.1594/PANGAEA.839740
- Holbourn, A; Kuhnt, W; Kochhann, KGD et al. (2015): Miocene stable isotope record of bulk carbonate from IODP Site 321-U1337. https://doi.org/10.1594/PANGAEA.839741