Mathematics – Logic
Scientific paper
Jun 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997gecoa..61.2505s&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 61, Issue 12, pp.2505-2510
Mathematics
Logic
26
Scientific paper
Measurements of 44 Ca/ 40 Ca, expressed as 44 Ca, were made on igneous rocks and on shell and bone material from modern organisms to investigate the magnitude and origins of calcium isotopic fractionation in nature. The results document a span of 4 in 44 Ca, measured with the double spike technique to a precision of ±0.15 . Volcanic rocks, including basalt and rhyolite, show little variability and cluster near 44 Ca = 0±0.2. Systematic analysis of biological samples indicates that biological processing of calcium discriminates against heavy isotopes, and that biological fractionation is the primary generator of calcium isotopic fractionation in nature. Preliminary data suggest that calcium becomes isotopically lighter as it moves through food chains. Calcium carbonate shells of marine microorganisms and deep-sea carbonate ooze have 44 Ca about 1.0 . lower than seawater; this fractionation causes seawater to be enriched in heavy calcium ( 44 Ca = +0.9) relative to igneous rocks. Marine organisms consequently are isotopically heavier than their terrestrial counterparts at similar trophic level. The calcium isotopic composition of living and fossil organisms may record information on diet and environment.
Depaolo Donald J.
Owens Thomas L.
Skulan Joseph
No associations
LandOfFree
Biological control of calcium isotopic abundances in the global calcium cycle does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Biological control of calcium isotopic abundances in the global calcium cycle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Biological control of calcium isotopic abundances in the global calcium cycle will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1473750