November 1, 2001Open Access
View Full PaperA dramatic Atlantic dissolution event at the onset of the last glaciation
Key Points
- This research investigates a major dissolution event in the Atlantic during the last glaciation, aiming to understand its causes and implications.
- Measurements of CaCO3 content and foraminifera weights were conducted in the western equatorial Atlantic.
- Analysis focused on the ion concentration and changes in circulation patterns in relation to glacial conditions.
- Deposition of Ethmodiscus rex was examined to assess circulation reorganization.
- A significant decrease in CO3= ion concentration was noted, too large for ocean acidification alone.
- Temporary strengthening of Antarctic Bottom Water penetration into the Atlantic was observed.
- Massive deposition of Ethmodiscus rex correlates with major circulation changes in the Atlantic.
Abstract
Measurements of the CaCO 3 content of the CaCO 3 size index and of foraminifera weights demonstrate that a prominent dissolution event occurred in the western equatorial Atlantic at the onset of the last glacial period. The decrease in CO 3 = ion concentration appears to have been too large to be accounted for by the ocean acidification associated with the demise of excess interglacial biomass. Rather, it appears to have been the result of a temporary strengthening of the penetration of the glacial equivalent Antarctic Bottom Water into the Atlantic. The co‐occurrence of massive Ethmodiscus rex deposition in the eastern equatorial Atlantic bears witness to a reorganization of circulation in the Atlantic. This reorganization may well reflect a temporary collapse of conveyor circulation at the onset of the last glaciation.