Stable isotope record of Cibicidoides spp. from early and middle Miocene sediments

The middle Miocene delta18O increase represents a fundamental change in the ocean-atmosphere system which, like late Pleistocene climates, may be related to deepwater circulation patterns. There has been some debate concerning the early to early middle Miocene deepwater circulation patterns. Specifically, recent discussions have focused on the relative roles of Northern Component Water (NCW) production and warm, saline deep water originating in the eastern Tethys. Our time series and time slice reconstructions indicate that NCW and Tethyan outflow water, two relatively warm deepwater masses, were produced from ~20 to 16 Ma. NCW was produced again from 12.5 to 10.5 Ma. Another feature of the early and middle Miocene oceans was the presence of a high delta13C intermediate water mass in the southern hemisphere, which apparently originated in the Southern Ocean. Miocene climates appear to be related directly to deepwater circulation changes. Deep-waters warmed in the early Miocene by ~3°C (?20 to 16 Ma) and cooled by a similar amount during the middle Miocene delta18O increase (14.8 to 12.6 Ma), corresponding to the increase (?20 Ma) and subsequent decrease (~16 Ma) in the production of NCW and Tethyan outflow water. Large (>0.6 per mil), relatively rapid (~0.5 m.y.) delta18O increases in both benthic and planktonic foraminifera (i.e., the Mi zones of Miller et al. (1991a) and Wright and Miller (1992a)) were superimposed in the long-term deepwater temperature changes; they are interpreted as reflecting continental ice growth events. Seven of these m.y. glacial/interglacial cycles have been recognized in the early to middle Miocene. Two of these glacial/interglacial cycles (Mi3 and Mi4) combined with a 2° to 3°C decrease in deepwater temperatures to produce the middle Miocene delta18O shift.

Data and Resources

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Cite this as

Wright, James D, Miller, Kenneth G, Fairbanks, Richard G (1992). Dataset: Stable isotope record of Cibicidoides spp. from early and middle Miocene sediments. https://doi.org/10.1594/PANGAEA.728102

DOI retrieved: 1992

Additional Info

Field Value
Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-3.0
Source https://doi.org/10.1594/PANGAEA.728102
Author Wright, James D
Given Name James D
Family Name Wright
More Authors
Miller, Kenneth G
Fairbanks, Richard G
Source Creation 1992
Publication Year 1992
Resource Type application/zip - filename: Wright_1992
Subject Areas
Name: Lithosphere

Name: Oceans

Name: Paleontology

Related Identifiers
Title: Early and Middle Miocene stable isotopes: implications for deepwater circulation and climate
Identifier: https://doi.org/10.1029/92PA00760
Type: DOI
Relation: IsSupplementTo
Year: 1992
Source: Paleoceanography
Authors: Wright James D , Miller Kenneth G , Fairbanks Richard G .