d11B and metal/Ca ratios versus size fractions in the Surface and deep dwelling species, ODP Holes 130-806B and 108-664C

DOI

We have assessed the reliability of several foraminifer-hosted proxies of the ocean carbonate system (d11B, B/Ca, and U/Ca) using Holocene samples from the Atlantic and Pacific oceans. We examined chemical variability over a range of test sizes for two surface-dwelling foraminifers (Globigerinoides sacculifer and Globigerinoides ruber). Measurements of d11B in G. ruber show no significant relationship with test size in either Atlantic or Pacific sites and appear to provide a robust proxy of surface seawater pH. Likewise there is no significant variability in the d11B of our Atlantic core top G. sacculifer, but we find that d11B increases with increasing test size for G. sacculifer in the Pacific. These systematic differences in d11B are inferred to be a consequence of isotopically light gametogenic calcite in G. sacculifer and its preferential preservation during postdepositional dissolution. The trace element ratio proxies of ocean carbonate equilibria, U/Ca and B/Ca, show systematic increases in both G. ruber and G. sacculifer with increasing test size, possibly as a result of changing growth rates. This behavior complicates their use in paleoceanographic reconstructions. In keeping with several previous studies we find that Mg/Ca ratios increase with increasing size fraction in our well-preserved Atlantic G. sacculifer but not in G. ruber. In contrast to previous interpretations we suggest that these observations reflect a proportionally larger influence of compositionally distinct gametogenic calcite in small individuals compared to larger ones. As with d11B this influences G. sacculifer but not G. ruber, which has negligible gametogenic calcite.

Supplement to: Ni, Yunyan; Foster, Gavin L; Bailey, Trevor R; Elliott, Tim; Schmidt, Daniela N; Pearson, Paul N; Haley, Brian A; Coath, Chris (2007): A core top assessment of proxies for the ocean carbonate system in surface-dwelling foraminifers. Paleoceanography, 22(3), PA3212

Identifier
DOI https://doi.org/10.1594/PANGAEA.832875
Related Identifier IsSupplementTo https://doi.org/10.1029/2006PA001337
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.832875
Provenance
Creator Ni, Yunyan ORCID logo; Foster, Gavin L ORCID logo; Bailey, Trevor R ORCID logo; Elliott, Tim ORCID logo; Schmidt, Daniela N ORCID logo; Pearson, Paul N ORCID logo; Haley, Brian A ORCID logo; Coath, Chris ORCID logo
Publisher PANGAEA
Publication Year 2007
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 494 data points
Discipline Earth System Research
Spatial Coverage (-23.227W, -1.467S, 159.361E, 0.319N); North Atlantic Ocean; North Pacific Ocean
Temporal Coverage Begin 1971-03-23T00:00:00Z
Temporal Coverage End 1990-02-23T01:30:00Z