Dynamic model of oscillatory zoning of trace elements in calcite: Double layer, inhibition, and self-organization

Journal Article · Sat Feb 01 00:00:00 EST 1992 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(92)90083-U· OSTI ID:5319846

Wang, Yifeng; Merino, E ^[1]

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1. Indiana Univ., Bloomington (United States)

Calcite growing from an aqueous solution containing growth-inhibiting cations such as Mn{sup 2+} can acquire oscillatory zoning of trace elements by this feedback: the growth-induced H{sup +} buildup at the growth surface makes the surface more positive, thus preventing inhibiting cations from attaching tot the growth sites and accelerating the growth rate. The increase in growth rate in turn further accelerates H{sup +} accumulation. This feedback is quantitatively modeled by a system of nonlinear differential equations that takes account of calcite growth, inhibition, diffusion, and mass continuity. For parameter values consistent with actual aqueous-ion diffusivities and concentrations in diagenetic waters, numerical solutions of the system of equations yield both oscillatory calcite growth and oscillatory concentration profiles of trace elements taken up by the calcite. The plausibility of the feedback makes it unnecessary to interpret oscillatory zoning of trace elements in calcite by calling on ad-hoc, large-scale, periodic changes in bulk water chemistry.

• OSTI ID: 5319846
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 56:2; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALCITE
CHEMICAL COMPOSITION
SORPTIVE PROPERTIES
THERMODYNAMIC MODEL
SEDIMENTARY ROCKS
DIAGENESIS
CRYSTAL GROWTH
GEOCHEMISTRY
GRAIN GROWTH
HYDROGEN IONS
MINERALIZATION
PRECIPITATION
CARBONATE MINERALS
CHARGED PARTICLES
CHEMISTRY
IONS
MATHEMATICAL MODELS
MINERALS
PARTICLE MODELS
ROCKS
SEPARATION PROCESSES
STATISTICAL MODELS
SURFACE PROPERTIES
580000* - Geosciences