Calcium carbonate vein compositions from drill sites in the Atlantic and Pacific
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| Format: | Dataset Open Access |
| Sprache: | en |
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PANGAEA
2013
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| author | Rausch, Svenja Böhm, Florian Bach, Wolfgang Klügel, Andreas Eisenhauer, Anton |
| author_facet | Rausch, Svenja Böhm, Florian Bach, Wolfgang Klügel, Andreas Eisenhauer, Anton |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Chemical (Sr, Mg) and isotopic (d18O, 87Sr/86Sr) compositions of calcium carbonate veins (CCV) in the oceanic basement were determined to reconstruct changes in Sr/Ca and Mg/Ca of seawater in the Cenozoic. We examined CCV from ten basement drill sites in the Atlantic and Pacific, ranging in age between 165 and 2.3 Ma. Six of these sites are from cold ridge flanks in basement <46 Ma, which provide direct information about seawater composition. CCV of these young sites were dated, using the Sr isotopic evolution of seawater. For the other sites, temperature-corrections were applied to correct for seawater-basement exchange processes. The combined data show that a period of constant/low Sr/Ca (4.46 - 6.22 mmol/mol) and Mg/Ca (1.12 - 2.03 mol/mol) between 165 and 30 Ma was followed by a steady increase in Mg/Ca ratios by a factor of three to modern ocean composition. Mg/Ca - Sr/Ca relations suggest that variations in hydrothermal fluxes and riverine input are likely causes driving the seawater compositional changes. However, additional forcing may be involved in explaining the timing and magnitude of changes. A plausible scenario is intensified carbonate production due to increased alkalinity input to the oceans from silicate weathering, which in turn is a result of subduction-zone recycling of CO2 from pelagic carbonate formed after the Cretaceous slow-down in ocean crust production rate. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_808642 |
| institution | PANGAEA |
| language | en |
| publishDate | 2013 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Calcium carbonate vein compositions from drill sites in the Atlantic and Pacific Rausch, Svenja Böhm, Florian Bach, Wolfgang Klügel, Andreas Eisenhauer, Anton Deep Sea Drilling Project; DSDP; Ocean Drilling Program; ODP Chemical (Sr, Mg) and isotopic (d18O, 87Sr/86Sr) compositions of calcium carbonate veins (CCV) in the oceanic basement were determined to reconstruct changes in Sr/Ca and Mg/Ca of seawater in the Cenozoic. We examined CCV from ten basement drill sites in the Atlantic and Pacific, ranging in age between 165 and 2.3 Ma. Six of these sites are from cold ridge flanks in basement <46 Ma, which provide direct information about seawater composition. CCV of these young sites were dated, using the Sr isotopic evolution of seawater. For the other sites, temperature-corrections were applied to correct for seawater-basement exchange processes. The combined data show that a period of constant/low Sr/Ca (4.46 - 6.22 mmol/mol) and Mg/Ca (1.12 - 2.03 mol/mol) between 165 and 30 Ma was followed by a steady increase in Mg/Ca ratios by a factor of three to modern ocean composition. Mg/Ca - Sr/Ca relations suggest that variations in hydrothermal fluxes and riverine input are likely causes driving the seawater compositional changes. However, additional forcing may be involved in explaining the timing and magnitude of changes. A plausible scenario is intensified carbonate production due to increased alkalinity input to the oceans from silicate weathering, which in turn is a result of subduction-zone recycling of CO2 from pelagic carbonate formed after the Cretaceous slow-down in ocean crust production rate. |
| title | Calcium carbonate vein compositions from drill sites in the Atlantic and Pacific |
| topic | Deep Sea Drilling Project; DSDP; Ocean Drilling Program; ODP |
| url | https://doi.org/10.1594/PANGAEA.808642 |