Mid-Pliocene deep-sea bottom water temperatures based on ostracode Mg/Ca ratios


We studied magnesium:calcium (Mg/Ca) ratios in shells of the deep-sea ostracode genus Krithe from a short interval in the middle Pliocene between 3.29 and 2.97 Ma using deep-sea drilling sites in the North and South Atlantic in order to estimate bottom water temperatures (BWT) during a period of climatic warmth. Results from DSDP and ODP Sites 552A, 610A, 607, 658A, 659A, 661A and 704 for the period Ma reveal both depth and latitudinal gradients of mean Mg/Ca values. Shallower sites (552A, 610A and 607) have higher mean Mg/Ca ratios (10.3, 9.7, 10.1 mmol/mol) than deeper sites (661A, 6.3 mmol/mol), and high latitude North Atlantic sites (552A, 610 and 607) have higher Mg/Ca ratios than low latitude (658A: 9.8 mmol/mol, 659A: 7.7 mmol/mol, 661A: 6.3 mmol/mol) and Southern Ocean (704: 8.0 mmol/mol) sites. Converting Mg/Ca ratios into estimated temperatures using the calibration of Dwyer et al. (1995) [Dwyer, G.S., Cronin, T.M., Baker, P.A., Raymo, M.E., Buzas, J.S., Corrège, T., 1995. North Atlantic deepwater temperature change during late Pliocene and late Quaternary climatic cycles. Science 270, 1347–1351] suggests that mean middle Pliocene bottom water temperatures at the study sites in the deep Atlantic were about the same as modern temperatures. However, brief pulses of elevated BWT occurred several times between 3.29 and 2.97 Ma in both the North and South Atlantic Ocean suggesting short-term changes in deep ocean circulation.

Supplement to: Cronin, Thomas M; Dowsett, Harry J; Dwyer, Gary S; Baker, Paul A; Chandler, Mark A (2005): Mid-Pliocene deep-sea bottom-water temperatures based on ostracode Mg/Ca ratios. Marine Micropaleontology, 54(3-4), 249-261

DOI https://doi.org/10.1594/PANGAEA.684703
Related Identifier https://doi.org/10.1016/j.marmicro.2004.12.003
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.684703
Creator Cronin, Thomas M; Dowsett, Harry J ORCID logo; Dwyer, Gary S; Baker, Paul A (ORCID: 0000-0001-9438-855X); Chandler, Mark A (ORCID: 0000-0002-6548-227X)
Publisher PANGAEA
Publication Year 2005
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 9 datasets
Discipline Earth System Research
Spatial Coverage (-79.378W, -46.880S, 161.227E, 56.043N); Caribbean Sea/RIDGE; North Atlantic/PLATEAU; South Pacific/Tasman Sea/CONT RISE; North Atlantic/FLANK; North Atlantic/RIDGE; Canarias Sea; South Atlantic Ocean
Temporal Coverage Begin 1979-08-16T00:00:00Z
Temporal Coverage End 1987-05-03T00:00:00Z