Orbital-scale climate variability of high-resolution records spanning 8.0-3.5 Ma from IODP Site 321-U1338 and ODP Site 982

Orbital-scale climate variability during the latest Miocene-early Pliocene is poorly understood due to a lack of high-resolution records spanning 8.0-3.5 Ma, which resolve all orbital cycles. Assessing this variability improves understanding of how Earth's system sensitivity to insolation evolves and provides insight into the factors driving the Messinian Salinity Crisis (MSC) and the Late Miocene Carbon Isotope Shift (LMCIS). New high-resolution benthic foraminiferal Cibicidoides mundulus d18O and d13C records from equatorial Pacific International Ocean Drilling Program Site U1338 are correlated to North Atlantic Ocean Drilling Program Site 982 to obtain a global perspective. Four long-term benthic d18O variations are identified: the Tortonian-Messinian, Miocene-Pliocene, and Early-Pliocene Oxygen Isotope Lows (8-7, 5.9-4.9, and 4.8-3.5 Ma) and the Messinian Oxygen Isotope High (MOH; 7-5.9 Ma). Obliquity-paced variability dominates throughout, except during the MOH. Eleven new orbital-scale isotopic stages are identified between 7.4 and 7.1 Ma. Cryosphere and carbon cycle sensitivities, estimated from d18O and d13C variability, suggest a weak cryosphere-carbon cycle coupling. The MSC termination coincided with moderate cryosphere sensitivity and reduced global ice sheets. The LMCIS coincided with reduced carbon cycle sensitivity, suggesting a driving force independent of insolation changes. The response of the cryosphere and carbon cycle to obliquity forcing is established, defined as Earth System Response (ESR). Observations reveal that two late Miocene-early Pliocene climate states existed. The first is a prevailing dynamic state with moderate ESR and obliquity-driven Antarctic ice variations, associated with reduced global ice volumes. The second is a stable state, which occurred during the MOH, with reduced ESR and lower obliquity-driven variability, associated with expanded global ice volumes.

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Drury, Anna Joy, John, Cédric M, Shevenell, Amelia E (2016). Dataset: Orbital-scale climate variability of high-resolution records spanning 8.0-3.5 Ma from IODP Site 321-U1338 and ODP Site 982. https://doi.org/10.1594/PANGAEA.856679

DOI retrieved: 2016

Additional Info

Field Value
Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-NC-SA-3.0
Source https://doi.org/10.1594/PANGAEA.856679
Author Drury, Anna Joy
Given Name Anna Joy
Family Name Drury
More Authors
John, Cédric M
Shevenell, Amelia E
Source Creation 2016
Publication Year 2016
Resource Type application/zip - filename: Drury_2016
Subject Areas
Name: Lithosphere

Name: Oceans

Name: Paleontology

Related Identifiers
Title: Evaluating climatic response to external radiative forcing during the late Miocene to early Pliocene: New perspectives from eastern equatorial Pacific (IODP U1338) and North Atlantic (ODP 982) locations
Identifier: https://doi.org/10.1002/2015PA002881
Type: DOI
Relation: IsSupplementTo
Year: 2016
Source: Paleoceanography
Authors: Drury Anna Joy , John Cédric M , Shevenell Amelia E .

Title: Table S1 Site overview (pdf-format): Overview of ODP, IODP and other sites
Identifier: https://store.pangaea.de/Publications/Drury-etal_2016/Table_S1_Site_overview.pdf
Type: DOI
Relation: References

Title: Table S4 Match Configuration (pdf-format): Overview of the configuration settings used for the first- (G1) and second- (G2) generation Match alignments
Identifier: https://store.pangaea.de/Publications/Drury-etal_2016/Table_S4_Match_Configuration.pdf
Type: DOI
Relation: References