Hodell, David A. and Curtis, Jason H. (2008) Oxygen and carbon isotopes of detrital carbonate in North Atlantic Heinrich Events. Marine Geology, 256 (1-4). pp. 30-35. DOI https://doi.org/10.1016/j.margeo.2008.09.010
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Abstract
We report oxygen and carbon isotope results of detrital carbonate grains from Heinrich layers at three sites in the North Atlantic located along a transect from the Labrador Sea to the eastern North Atlantic. Oxygen isotopic values of individual detrital carbonate grains from six Heinrich layers at all sites average − 5.6‰ ± 1.5‰ (1σ; n = 166), reflecting values of dolomitic limestone derived from source areas in northeastern Canada. The δ18O of bulk carbonate at Integrated Ocean Drilling Program (IODP) Site U1308 (re-occupation of Deep Sea Drilling Project (DSDP) Site 609) in the eastern North Atlantic records the proportion of detrital to biogenic carbonate and δ18O decreases to − 5‰ during Heinrich (H) events 1, 2, 4 and 5 relative to a background value of ∼ 1 to 2‰ for biogenic carbonate. Bulk δ18O also decreases during H3 and H6 but only attains values of − 1‰, indicating either a greater proportion of biogenic-to-detrital carbonate or a different source. Because the δ18O of detrital carbonate is ∼ 9‰ lower than foraminifer carbonate, any fine-grained detrital carbonate not removed from the inner test chambers will lower foraminifer δ18O. We conclude bulk carbonate δ18O is a sensitive proxy for detrital carbonate and may be useful for identifying Heinrich layers in cores within and near the margins of the North Atlantic ice-rafted detritus (IRD) belt.
Item Type: | Article |
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Uncontrolled Keywords: | NIL AREP |
Subjects: | 01 - Climate Change and Earth-Ocean Atmosphere Systems |
Divisions: | 01 - Climate Change and Earth-Ocean Atmosphere Systems |
Journal or Publication Title: | Marine Geology |
Volume: | 256 |
Page Range: | pp. 30-35 |
Identification Number: | https://doi.org/10.1016/j.margeo.2008.09.010 |
Depositing User: | Sarah Humbert |
Date Deposited: | 13 Dec 2011 18:04 |
Last Modified: | 23 Jul 2013 10:03 |
URI: | http://eprints.esc.cam.ac.uk/id/eprint/2274 |
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