X-ray micro-CT scanning of tests of three planktic foraminiferal species to clarify dissolution process and progress

DOI

Evaluation of foraminiferal test dissolution in deep-sea sediments facilitates reconstruction of seawater chemistry. Here we observed test dissolution processes of the planktic foraminifera Trilobatus sacculifer, Globigerinoides ruber, and Neogloboquadrina dutertrei from mid-latitudes of the western North Pacific; in these three species, we tested the ability of a new dissolution index using data from X-ray micro-computed tomography scanning (XMCT). Although the dissolution process of foraminiferal tests differed slightly among species, dissolution of all species was equally assessed by the calcite density distribution (%Low-CT-number calcite volume) calculated from the CT number histogram. As for T. sacculifer and G. ruber, the test area density, a conventional proxy for assessing test condition based on weight measurement, is affected by variance in the thickness of the outermost chamber wall; thus, this conventional proxy can be affected by sea surface conditions during test calcification. In contrast, the relationship between the %Low-CT-number calcite volume of tests and the deep seawater calcite saturation state suggests that XMCT scanning is applicable for evaluating the intensity of foraminiferal test dissolution at the under-saturated deep seafloor in this area and is an invaluable proxy for detecting deep seawater carbonate ion concentration changes on glacial-interglacial timescales.

Supplement to: Iwasaki, Shinya; Kimoto, K; Okazaki, Y; Ikehara, M (2019): Micro‐CT Scanning of Tests of Three Planktic Foraminiferal Species to Clarify DissolutionProcess and Progress. Geochemistry, Geophysics, Geosystems

Identifier
DOI https://doi.org/10.1594/PANGAEA.907942
Related Identifier https://doi.org/10.1029/2019GC008456
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.907942
Provenance
Creator Iwasaki, Shinya ORCID logo; Kimoto, Katsunori; Okazaki, Yusuke ORCID logo; Ikehara, Minoru ORCID logo
Publisher PANGAEA
Publication Year 2019
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (133.467W, 29.217S, 138.700E, 33.770N)