A secondary ionization mass spectrometry calibration of Cibicidoides pachyderma Mg/Ca with temperature
Curry, William B.
Marchitto, Thomas M.
MetadataShow full item record
An evaluation of C. pachyderma Mg/Ca using a new suite of warm water multicores from the Florida Straits shows that the slope of Mg/Ca with temperature is shallower than previously thought. Using secondary ionization mass spectrometry, we have documented that the distribution of magnesium within the polished walls of foraminiferal tests is Gaussian, suggesting that the Mg/Ca in these samples is not affected by the addition of a secondary high-magnesium calcite in the walls. The Mg/Ca within a typical C. pachyderma test varies by about ±20% (1σ/μ · 100), and the variability increases slightly in tests with higher Mg/Ca. The regression of C. pachyderma Mg/Ca with temperature has a slope of 0.13 ± 0.05 mmol mol−1 per °C, indistinguishable from the slope observed in inductively coupled plasma–mass spectrometry measurements from a different subset of the same multicores, but about one half the slope of previously published calibrations. The largest differences between the calibrations comes at the warm water end of the regression, where previously published C. pachyderma Mg/Ca values from Little Bahama Bank are at least 3 mmol mol−1 higher than observed in these new cores. The reasons for this difference are not fully known but are most likely related to diagenesis at Little Bahama Bank.
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q04009, doi:10.1029/2007GC001620.
Showing items related by title, author, creator and subject.
Shearman, R. Kipp; Lentz, Steven J. (American Meteorological Society, 2010-05)Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent buoy and shore-based ...
Lund, David C.; Curry, William B. (American Geophysical Union, 2006-05-05)The salinity and temperature of the Florida Current are key parameters affecting the transport of heat into the North Atlantic, yet little is known about their variability on centennial time scales. Here we report replicated, ...
Wells, Andrew J.; Cenedese, Claudia; Farrar, J. Thomas; Zappa, Christopher J. (American Meteorological Society, 2009-11)The aqueous thermal boundary layer near to the ocean surface, or skin layer, has thickness O(1 mm) and plays an important role in controlling the exchange of heat between the atmosphere and the ocean. Theoretical arguments ...