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Atmospheric iron fluxes over the last deglaciation: Climatic implications
Author(s) -
Gaspari Vania,
Barbante Carlo,
Cozzi Giulio,
Cescon Paolo,
Boutron Claude F.,
Gabrielli Paolo,
Capodaglio Gabriele,
Ferrari Christophe,
Petit Jean Robert,
Delmonte Barbara
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024352
Subject(s) - deglaciation , interglacial , glacial period , holocene , ice core , geology , oceanography , ice age , physical geography , climatology , geomorphology , geography
A decrease in the micronutrient iron supply to the Southern Ocean is widely believed to be involved in the atmospheric CO 2 increase during the last deglaciation. Here we report the first record of atmospheric iron fluxes as determined in 166 samples of the Dome C ice core and covering the last glacial‐interglacial transition (22–9 kyr B.P.). It reveals a decrease in fallout flux from 24 × 10 −2 mg Fe m −2 yr −1 during the Last Glacial Maximum to 0.7 × 10 −2 mg Fe m −2 yr −1 at the onset of the Holocene. The acid leachable fraction of iron determined in our samples was the 60% of the total iron mass in glacial samples, about twice the value found for Holocene samples. This emerging difference in iron solubility over different climatic stages provides a new insight for evaluating the iron hypothesis over glacial/interglacial periods.