Unknown
PANGAEA
In:
Supplement to: Andrews, Julian E; Funnell, Brian M; Jickells, Timothy D; Shackleton, Nicholas J; Swallow, Jane E; Williams, Ann C; Young, Kathryn A (1990): Preliminary assessment of cyclic variations in foraminifers, barite, and cadmium/calcium ratios in Early Pleistocene sediments from Hole 709C (equatorial Indian Ocean). In: Duncan, RA; Backmann, J; Peterson, LC; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 115, 611-619, https://doi.org/10.2973/odp.proc.sr.115.176.1990
Publication Date:
2024-01-09
Description:
During three to four d18O cycles (determined on Globigerinoides ruber), more positive d18O (= higher global ice volume) values correlated with higher Globorotalia menardii percentages, total numbers of benthic foraminifers, number of benthic foraminifer species, and the percent of total foraminifers composed of benthic foraminifers. During the same intervals, barite and insoluble residues also generally recorded higher values; however, there was no clear evidence of systematic variation in cadmium/calcium ratios (in benthic foraminifers). Maximum percentages of Globigerinoides sacculifer and Globigerinoides ruber correlate with more negative d18O (= lower global ice volume) values, although they sometimes appear to lead the d18O changes by 〈 =4,000 yr.
The increase in percentage of the tropical "divergence" planktonic foraminifer species G. menardii and the reduction of the "nondivergence" tropical species G. ruber and G. sacculifer at times of inferred ice growth is attributed to periodic intensification of divergence associated with the Equatorial Counter Current. Barite and insoluble residue sedi- mentation at the site also generally show a relative increase at those times.
Keywords:
115-709C; DRILL; Drilling/drill rig; Joides Resolution; Leg115; Ocean Drilling Program; ODP; South Indian Ridge, South Indian Ocean
Type:
Dataset
Format:
application/zip, 2 datasets
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