Stable isotope record, carbonate and organic carbon content of the Miocene section of IODP Site 321-U1337


Autoria(s): Holbourn, Ann; Kuhnt, Wolfgang; Kochhann, Karlos GD; Andersen, Nils; Meier, KJ Sebastian
Cobertura

LATITUDE: 3.833000 * LONGITUDE: -123.206000

Data(s)

27/11/2015

Resumo

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.

Formato

application/zip, 3 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.839743

doi:10.1594/PANGAEA.839743

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Holbourn, Ann; Kuhnt, Wolfgang; Kochhann, Karlos GD; Andersen, Nils; Meier, KJ Sebastian (2015): Global perturbation of the carbon cycle at the onset of the Miocene Climatic Optimum. Geology, 43(2), 123-126, doi:10.1130/G36317.1

Palavras-Chave #321-U1337; Age; AGE; CaCO3; Calcium carbonate; Carbon, organic, total; COMPCORE; Composite Core; d13C carb; d18O carb; delta 13C, carbonate; delta 18O, carbonate; Depth; Depth, bottom/max; Depth, composite top; DEPTH, sediment/rock; Depth, top/min; Depth bot; Depth c top; Depth top; Exp321; Foram bent d13C; Foram bent d18O; Foraminifera, benthic d13C; Foraminifera, benthic d18O; Integrated Ocean Drilling Program / International Ocean Discovery Program; IODP; Joides Resolution; Label; mbsf; ODP sample designation; Pacific Equatorial Age Transect II / Juan de Fuca; Sample code/label; TOC; vs. VPDB
Tipo

Dataset