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Title: sup 13 C and sup 18 O isotopic disequilibrium in biological carbonates: II. In vitro simulation of kinetic isotope effects

Abstract

Biological carbonates are built largely from CO{sub 2}, which diffuses across the skeletogenic membrane and reacts to form HCO{sub 3}{sup {minus}}. Kinetic discrimination against the heavy isotopes {sup 18}O and {sup 13}C during CO{sub 2} hydration and hydroxylation apparently causes most of the isotopic disequilibrium observed in biological carbonates. These kinetic isotope effects are expressed when the extracytosolic calcifying solution is thin and alkaline, and HCO{sub 3}{sup {minus}} precipitates fairly rapidly as CaCO{sub 3}. In vitro simulation of the calcifying environment produced heavy isotope depletions qualitatively similar to, but somewhat more extreme than, those seen in biological carbonates. Isotopic equilibration during biological calcification occurs through CO{sub 2} exchange across the calcifying membrane and by admixture ambient waters (containing HCO{sub 3}{sup {minus}}) into the calcifying fluids. Both mechanisms tend to produce linear correlations between skeletal {delta}{sup 13}C and {delta}{sup 18}O.

Authors:
 [1]
  1. Univ. of Washington, Seattle (USA)
Publication Date:
OSTI Identifier:
7000662
Resource Type:
Journal Article
Journal Name:
Geochimica et Cosmochimica Acta; (USA)
Additional Journal Information:
Journal Volume: 53:1; Journal ID: ISSN 0016-7037
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; 59 BASIC BIOLOGICAL SCIENCES; ARAGONITE; BIOCHEMICAL REACTION KINETICS; PRECIPITATION; CORALS; EXOSKELETON; MINERAL CYCLING; BIOGEOCHEMISTRY; CARBON 13; CARBON DIOXIDE; CHEMICAL COMPOSITION; ECUADOR; EQUILIBRIUM; HYDRATION; HYDROXYLATION; ISOTOPE RATIO; OXYGEN 18; PARTITION; REEFS; ALKALINE EARTH METAL COMPOUNDS; ANIMALS; BODY; CALCIUM CARBONATES; CALCIUM COMPOUNDS; CARBON COMPOUNDS; CARBON ISOTOPES; CARBON OXIDES; CARBONATE MINERALS; CARBONATES; CHALCOGENIDES; CHEMISTRY; CNIDARIA; COELENTERATA; DEVELOPING COUNTRIES; EVEN-EVEN NUCLEI; EVEN-ODD NUCLEI; GEOCHEMISTRY; GEOLOGIC STRUCTURES; INVERTEBRATES; ISOTOPES; KINETICS; LATIN AMERICA; LIGHT NUCLEI; MINERALS; NUCLEI; ORGANS; OXIDES; OXYGEN COMPOUNDS; OXYGEN ISOTOPES; REACTION KINETICS; SEPARATION PROCESSES; SKELETON; SOLVATION; SOUTH AMERICA; STABLE ISOTOPES; 580000* - Geosciences; 550500 - Metabolism

Citation Formats

McConnaughey, T. sup 13 C and sup 18 O isotopic disequilibrium in biological carbonates: II. In vitro simulation of kinetic isotope effects. United States: N. p., 1989. Web. doi:10.1016/0016-7037(89)90283-4.
McConnaughey, T. sup 13 C and sup 18 O isotopic disequilibrium in biological carbonates: II. In vitro simulation of kinetic isotope effects. United States. https://doi.org/10.1016/0016-7037(89)90283-4
McConnaughey, T. 1989. "sup 13 C and sup 18 O isotopic disequilibrium in biological carbonates: II. In vitro simulation of kinetic isotope effects". United States. https://doi.org/10.1016/0016-7037(89)90283-4.
@article{osti_7000662,
title = {sup 13 C and sup 18 O isotopic disequilibrium in biological carbonates: II. In vitro simulation of kinetic isotope effects},
author = {McConnaughey, T},
abstractNote = {Biological carbonates are built largely from CO{sub 2}, which diffuses across the skeletogenic membrane and reacts to form HCO{sub 3}{sup {minus}}. Kinetic discrimination against the heavy isotopes {sup 18}O and {sup 13}C during CO{sub 2} hydration and hydroxylation apparently causes most of the isotopic disequilibrium observed in biological carbonates. These kinetic isotope effects are expressed when the extracytosolic calcifying solution is thin and alkaline, and HCO{sub 3}{sup {minus}} precipitates fairly rapidly as CaCO{sub 3}. In vitro simulation of the calcifying environment produced heavy isotope depletions qualitatively similar to, but somewhat more extreme than, those seen in biological carbonates. Isotopic equilibration during biological calcification occurs through CO{sub 2} exchange across the calcifying membrane and by admixture ambient waters (containing HCO{sub 3}{sup {minus}}) into the calcifying fluids. Both mechanisms tend to produce linear correlations between skeletal {delta}{sup 13}C and {delta}{sup 18}O.},
doi = {10.1016/0016-7037(89)90283-4},
url = {https://www.osti.gov/biblio/7000662}, journal = {Geochimica et Cosmochimica Acta; (USA)},
issn = {0016-7037},
number = ,
volume = 53:1,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1989},
month = {Sun Jan 01 00:00:00 EST 1989}
}