(Table A1) CaCO3 contents and Sr/Ca ratios in ODP Leg 130, 138 and 154


Strontium/calcium (Sr/Ca) ratios in bulk and foraminiferal calcite have been used to constrain the history of Sr/Ca in the oceans and to evaluate calcite diagenetic alteration. However bulk Sr/Ca records also may be influenced by differences in Sr uptake and/or in the diagenetic susceptibility of different calcium carbonate sedimentary components. We present data on the sediment size fraction and calcium carbonate distribution in bulk samples, Sr/Ca in a range of sedimentary size components, and Sr/Ca in bulk sediments. Ocean Drilling Program samples from sites on Ontong Java Plateau and Ceara Rise (in the western equatorial Pacific and Atlantic, respectively) and from sites in the eastern equatorial Pacific were selected to represent progressive stages in the diagenetic pathway from the sea floor through a range of burial depths equivalent to sediment ages of ~5.6, ~9.4, and ~37.1 Ma. Samples were subdivided by size to produce a unique data set of size-specific Sr/Ca ratios. Fine fraction (<45 ?m) Sr/Ca ratios are higher than those of all corresponding coarse fractions, indicating that fine nannofossil-dominated calcite has a Sr partition coefficient 1.3–1.5 times greater than that of coarse foraminifera-dominated calcite. Thus, absolute values of bulk Sr/Ca in contemporaneous samples reflect, in part, the ratio of fine to coarse calcite sedimentary components. Sr/Ca values in fine and coarse components also behave differently in their response to pre-burial dissolution and to recrystallization at depth. Coarse size components are sensitive to bottom water carbonate ion undersaturation, and they lose original Sr/Ca differences among contemporary samples over not, vert, similar10 my. In contrast, fine components recrystallize faster in more deeply buried samples. Interpretation of the historical Sr/Ca record is complicated by post-depositional diagenetic artifacts, and thus our data do not provide clear evidence of specific temporal changes in oceanic Sr/Ca ratios over the past 10 million years. This paper represents the first systematic attempt to examine trends in calcite Sr/Ca as a function of sediment size fraction and age.

Depth, sediment = mbsf

Supplement to: Andreasen, Gretchen Hampt; Delaney, Margaret Lois (2000): Bulk calcite size fraction distribution and Sr/Ca composition for deep-sea sediments at selected age horizons. Marine Geology, 169(1-2), 185-205

DOI https://doi.org/10.1594/PANGAEA.745110
Related Identifier https://doi.org/10.1016/S0025-3227(00)00051-7
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.745110
Creator Andreasen, Gretchen Hampt; Delaney, Margaret Lois
Publisher PANGAEA
Publication Year 2000
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 891 data points
Discipline Earth System Research
Spatial Coverage (-43.489W, -3.095S, 156.625E, 7.921N); North Pacific Ocean; West equatorial Pacific Ocean; South Pacific Ocean; South Atlantic Ocean
Temporal Coverage Begin 1990-01-29T15:30:00Z
Temporal Coverage End 1994-03-21T08:45:00Z