Journal
CHEMICAL GEOLOGY
Volume 398, Issue -, Pages 11-21Publisher
ELSEVIER
DOI: 10.1016/j.chemgeo.2015.01.019
Keywords
Coral; Boron; Bleach; Cleaning; Peroxide; Aragonite
Categories
Funding
- Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies
- NSF [OCE-1338320]
- ARC Super Science Fellowship
- NSF International Research Fellowship
- NSF Graduate Research Fellowship
- Western Australian Premiers Fellowship
- Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation (Japan Society of the Promotion of Science) [G2301]
Ask authors/readers for more resources
In preparing calcium carbonate samples for the measurement of various geochemical proxies, it is often necessary to remove contaminating phases while leaving the phase of interest altered as little as possible. Here we evaluate the effects of some common cleaning protocols (rinsing (H2O), bleach (similar to 3% NaOCl), hydrogen peroxide (30%), sodiumhydroxide (0.006-0.1M NaOH), and acid leaching (0.05 N HNO3)) on the elemental (Li, B, Na, Mg, Sr, Ba, Pb, and U) and boron isotope composition of both biogenic and synthetic calcium carbonates formed in marine environments. In untreated samples, the presence of elevated concentrations of Na and Mg, the most abundant cations in seawater, can be reduced with minimal cleaning (e.g. rinsing). Cleaning protocols that cause partial dissolution are problematic, especially for samples that are compositionally heterogeneous because the remaining sample may be biased towards particular phases with distinctive elemental or isotopic compositions. We show that the use of either acid or unbuffered hydrogen peroxide can lead to partial dissolution which was associated with an increase in the U/Ca ratio of the remaining sample. Bleaching or rinsing with water did not result in significant sample dissolution, suggesting that these cleaning techniques may be safely used on heterogeneous samples. Cleaning treatments, other than those resulting in significant dissolution of heterogeneous samples, had no significant effect on delta B-11, suggesting that boron isotopes are generally robust to the effects of sample pre-treatment. (C) 2015 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available