Publication Date:
2024-01-09
Description:
Benthic foraminiferal d13C and Cd/Ca studies suggest that deep Atlantic circulation during the Last Glacial Maximum was very different from today, with high-nutrient (low d13C, high Cd) deep Southern Ocean Water (SOW) penetrating far into the North Atlantic. However, if some glacial d13C values are biased by productivity artifacts and/or air-sea exchange processes, then the existing d13C data may be consistent with the continual dominance of North Atlantic Deep Water (NADW). Cibicidoides wuellerstorfi Cd/Ca results presented here indicate that the glacial North Atlantic was strongly enriched in dissolved Cd below ~2500 m depth. If NADW formation was still vigorous relative to SOW formation, these data could be explained by either increased preformed nutrient levels in the high-latitude North Atlantic or by increased organic matter remineralization within lower NADW. High glacial Zn/Ca values in the same samples, however, are best explained by a substantially increased mixing with Zn-rich SOW. The cause was most likely a partial replacement of NADW by less dense Glacial North Atlantic Intermediate Water. This reorganization also lowered deep North Atlantic [CO3]2- concentrations by perhaps 10 to 15 µmol/kg.
Keywords:
162-980; Cadmium/Calcium ratio; Calcium; CH8X; CHN82-04; CHN82-11; CHN82-15; CHN82-20; Comment; COMPCORE; Composite Core; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Elevation of event; Epoch; Event label; Jean Charcot; Joides Resolution; Latitude of event; Leg162; Longitude of event; Manganese/Calcium ratio; Ocean Drilling Program; ODP; PC; Piston corer; South Atlantic Ocean; Species; V28; V28-73; V29; V29-193; V29-202; V29-204; Vema; Zinc/Calcium ratio
Type:
Dataset
Format:
text/tab-separated-values, 445 data points
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