Mg/Ca paleothermometry in high salinity environments
Planktonic foraminiferal Mg/Ca ratios have become a fundamental temperature proxy in past climate reconstructions. However, in the highly evaporative seas of the tropics and subtropics, anomalously high planktonic foraminiferal Mg/Ca ratios arise, possibly linked to high salinities. The extent to wh...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/80029 2023-05-15T18:00:47+02:00 Mg/Ca paleothermometry in high salinity environments Hoogakker, B.A.A. Klinkhammer, G Elderfield, H Rohling, Eelco Hayward, Chris 2015-12-13T22:45:56Z http://hdl.handle.net/1885/80029 unknown Elsevier 0012-821X http://hdl.handle.net/1885/80029 Earth and Planetary Science Letters Journal article 2015 ftanucanberra 2015-12-28T23:37:31Z Planktonic foraminiferal Mg/Ca ratios have become a fundamental temperature proxy in past climate reconstructions. However, in the highly evaporative seas of the tropics and subtropics, anomalously high planktonic foraminiferal Mg/Ca ratios arise, possibly linked to high salinities. The extent to which salinity affects Mg uptake into foraminiferal calcite remains disputed. Some studies suggest only minor salinity effects, whereas others suggest a dominant role. Here, we present new data from the highly saline (> 40) Red Sea, which separate pure foraminiferal calcite from other phases. The results show that high Mg/Ca ratios (7 to 13 mmol/mol), found by conventional analysis of planktonic foraminifera from a Red Sea sediment core, are not caused by increased Mg uptake into foraminiferal calcite in a high salinity setting (e.g. beyond those predicted by culturing studies), but instead result from secondary high Mg-calcite overgrowths. The overgrowths likely formed near the sediment-seawater interface, from CaCO3 supersaturated interstitial seawater. Article in Journal/Newspaper Planktonic foraminifera Australian National University: ANU Digital Collections |
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Open Polar |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
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unknown |
description |
Planktonic foraminiferal Mg/Ca ratios have become a fundamental temperature proxy in past climate reconstructions. However, in the highly evaporative seas of the tropics and subtropics, anomalously high planktonic foraminiferal Mg/Ca ratios arise, possibly linked to high salinities. The extent to which salinity affects Mg uptake into foraminiferal calcite remains disputed. Some studies suggest only minor salinity effects, whereas others suggest a dominant role. Here, we present new data from the highly saline (> 40) Red Sea, which separate pure foraminiferal calcite from other phases. The results show that high Mg/Ca ratios (7 to 13 mmol/mol), found by conventional analysis of planktonic foraminifera from a Red Sea sediment core, are not caused by increased Mg uptake into foraminiferal calcite in a high salinity setting (e.g. beyond those predicted by culturing studies), but instead result from secondary high Mg-calcite overgrowths. The overgrowths likely formed near the sediment-seawater interface, from CaCO3 supersaturated interstitial seawater. |
format |
Article in Journal/Newspaper |
author |
Hoogakker, B.A.A. Klinkhammer, G Elderfield, H Rohling, Eelco Hayward, Chris |
spellingShingle |
Hoogakker, B.A.A. Klinkhammer, G Elderfield, H Rohling, Eelco Hayward, Chris Mg/Ca paleothermometry in high salinity environments |
author_facet |
Hoogakker, B.A.A. Klinkhammer, G Elderfield, H Rohling, Eelco Hayward, Chris |
author_sort |
Hoogakker, B.A.A. |
title |
Mg/Ca paleothermometry in high salinity environments |
title_short |
Mg/Ca paleothermometry in high salinity environments |
title_full |
Mg/Ca paleothermometry in high salinity environments |
title_fullStr |
Mg/Ca paleothermometry in high salinity environments |
title_full_unstemmed |
Mg/Ca paleothermometry in high salinity environments |
title_sort |
mg/ca paleothermometry in high salinity environments |
publisher |
Elsevier |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/80029 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_source |
Earth and Planetary Science Letters |
op_relation |
0012-821X http://hdl.handle.net/1885/80029 |
_version_ |
1766170018064629760 |