(Tables 2, 3) Element ratios of planktonic foraminifera from western Pacific surface sediments

DOI

Accurately quantifying deep-sea calcite dissolution is crucial for understanding the role of the marine carbonate system in regulating atmospheric pCO2 over millennia. We compare a foraminifer-fragmentation-based calcite dissolution proxy (Globorotalia menardii fragmentation index (MFI)) to Mg/Ca, Sr/Ca, and Mg/Sr in several species of deep dwelling planktonic foraminifers. We conducted microfossil and geochemical analyses on the same core top samples taken at different depths on the Ontong Java Plateau to maximize the dissolution signal and minimize the temperature overprint on our data. We also compare elemental ratios from planktonic foraminifer tests to modern bottom water [CO3]2- undersaturation and model-derived estimates of percent calcite dissolved in deep-sea sediments. We find clear linear decreases in Mg/Ca or Mg/Sr in G. menardii and Pulleniatina obliquiloculata with increasing (1) bottom water [CO3]2- undersaturation, (2) percent calcite dissolved in sediments calculated with biogeochemical modeling, (3) MFI, and (4) percent calcite dissolved derived from MFI. These findings lend further support to MFI as a calcite dissolution proxy for deep-sea sediments. In contrast, we find no significant correlation between Sr/Ca and independent dissolution indicators. Our results suggest that Mg/Ca and Mg/Sr from deep dwelling foraminifers could potentially be used as calcite dissolution proxies in combination with independent water temperature estimates. Likewise, establishing the relationship between MFI and dissolution-induced changes in the Mg/Ca of surface-dwelling foraminifers could provide a tool to correct Mg/Ca–derived sea surface temperature reconstructions for calcite dissolution.

Supplement to: Mekik, Figen; Francois, Roger (2006): Tracing deep-sea calcite dissolution: Agreement between the| Globorotalia menardii fragmentation index and elemental ratios (Mg/Ca and Mg/Sr) in planktonic foraminifers. Paleoceanography, 21(4), PA4219

Identifier
DOI https://doi.org/10.1594/PANGAEA.832902
Related Identifier https://doi.org/10.1029/2006PA001296
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.832902
Provenance
Creator Mekik, Figen; Francois, Roger
Publisher PANGAEA
Publication Year 2006
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 363 data points
Discipline Earth System Research
Spatial Coverage (155.865W, -2.083S, 162.683E, -0.003N)
Temporal Coverage Begin 1975-04-18T00:00:00Z
Temporal Coverage End 1975-04-29T00:00:00Z