A model of oscillatory zoning in solid solutions grown from aqueous solutions: Applications to the (Ba,Sr)SO 4 system

L’Heureux, Ivan; Jamtveit, Bjørn

doi:10.1016/s0016-7037(01)00792-x

Cited by 35 publications

(28 citation statements)

References 21 publications

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“… 9 , 30 , the solubility constants of the solid solution endmembers must differ by several orders of magnitude. In other work 31 – 33 , modeling of crystal growth at the mineral-fluid interface supports the hypothesis that compositional zonation is promoted by a difference in the endmember solubility constants of several orders of magnitude, combined with diffusion-limited solute transport at the mineral-fluid interface. In the example of (Ba, Sr)SO 4 , the solubility product constant (K sp ) values of endmembers BaSO 4 (pK sp = 9.98) 34 and SrSO 4 (pK sp = 6.63) 35 differ by three orders of magnitude.…”

Section: Introductionmentioning

confidence: 52%

Nanospectroscopy Captures Nanoscale Compositional Zonation in Barite Solid Solutions

Ling

Hunter

Fitts

et al. 2018

Sci Rep

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Scientists have long suspected that compositionally zoned particles can form under far-from equilibrium precipitation conditions, but their inferences have been based on bulk solid and solution measurements. We are the first to directly observe nanoscale trace element compositional zonation in <10 µm-sized particles using X-ray fluorescence nanospectroscopy at the Hard X-ray Nanoprobe (HXN) Beamline at National Synchrotron Light Source II (NSLS-II). Through high-resolution images, compositional zonation was observed in barite (BaSO4) particles precipitated from aqueous solution, in which Sr2+ cations as well as HAsO42− anions were co-precipitated into (Ba,Sr)SO4 or Ba(SO4,HAsO4) solid solutions. Under high salinity conditions (NaCl ≥ 1.0 M), bands contained ~3.5 to ~5 times more trace element compared to the center of the particle formed in early stages of particle growth. Quantitative analysis of Sr and As fractional substitution allowed us to determine that different crystallographic growth directions incorporated trace elements to different extents. These findings provide supporting evidence that barite solid solutions have great potential for trace element incorporation; this has significant implications for environmental and engineered systems that remove hazardous substances from water.

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Section: Introductionmentioning

confidence: 52%

Nanospectroscopy Captures Nanoscale Compositional Zonation in Barite Solid Solutions

Ling

Hunter

Fitts

et al. 2018

Sci Rep

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“…This difference effectively shuts down oscillatory growth of metamorphic garnet by this mechanism [ L'Heureux and Fowler , 1996]. A modified kinetic model has also been proposed for synthetic sulfates [ L'Heureux and Jamtveit , 2002], and whereas it cannot be excluded theoretically, it also cannot be tested because it involves nonmeasurable terms.…”

Section: Interpretation Of Oscillationsmentioning

confidence: 99%

Oscillatory‐ and sector‐zoned garnets record cyclic (?) rapid thrusting in central Nepal

Kohn

2004

Geochem Geophys Geosyst

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[1] Garnets with oscillatory zoning (repeated compositional reversals) and sector zoning (crystallographically controlled compositional differences) were discovered in rocks from near the Main Central Thrust in the Langtang region, central Nepal. This zoning results from crystal growth kinetic effects related to extraordinarily rapid, possibly cyclic thrusting. If cyclic thrusting occurred, then timescales of thrust rate inhomogeneities are $25 Kyr, implying that satellite determination of modern fault movement rates may not accurately reflect slip rates or strain partitioning in orogens on timescales exceeding thousands of years. Sector zoning in Ca but not Y, Mn, or Mg implies maximum intracrystalline diffusion rates for Ca of $10 À21 cm 2 /s at 550°C but faster rates for other elements.

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“…It shows how porosity is modified by compaction and the reactive kinetics of the precipitation/dissolution of minerals. Equation (9) indicates that…”

Section: Mass Conservation Equationsmentioning

confidence: 99%

“…On the other hand, in a nonlinear nonequilibrium geosystem, the presence of positive feedback may result in a pattern formation that is self-organized even in an external environment that does not change (intrinsic mechanisms) [2,4]. Examples of such geochemical self-organization are found in the oscillatory zoning of solid solutions series [4,[6][7][8][9], Liesegang band formation [10][11][12][13][14][15][16][17], orbicular granites [7,18], and cyclic layering in igneous bodies [19,20].…”

Section: Introductionmentioning

confidence: 99%

Diagenetic Self-Organization and Stochastic Resonance in a Model of Limestone-Marl Sequences

L’Heureux

2018

Geofluids

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Banded patterns in limestone-marl sequences (“rhythmites”) form widespread sediments typical of shallow marine environments. They are characterized by alternations of limestone-rich layers and softer calcareous-clayey material (marl) extending over hundreds of meters with a thickness of a few tens of meters. The banded sequences are usually thought to result from systematic variations in the external environment, but the pattern may be distorted by diagenetic nonlinear processes. Here, we present a reactive-transport model for the formation of banded patterns in such a system. The model exhibits interesting features typical of nonlinear dynamical systems: (i) the existence of self-organized oscillating patterns between a calcite-rich mode (“limestone”) and a calcite-poor one (“marl”) for fixed environmental conditions and (ii) bistability between these two modes. We then illustrate the phenomena of stochastic resonance, whereby the multistable system is driven by a small external periodic signal (the 100,000 years’ Milankovitch cycle comes to mind) that is too weak to generate oscillations between the states on its own. In the presence of random fluctuations, however, the system generates transitions between the calcite-rich and calcite-poor states in statistical synchrony with the external forcing. The signal-to-noise ratio exhibits many maxima as the noise strength is varied. Hence, this amplification effect is maximized for specific values of the noise strength.

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A model of oscillatory zoning in solid solutions grown from aqueous solutions: Applications to the (Ba,Sr)SO 4 system

Cited by 35 publications

References 21 publications

Nanospectroscopy Captures Nanoscale Compositional Zonation in Barite Solid Solutions

Nanospectroscopy Captures Nanoscale Compositional Zonation in Barite Solid Solutions

Oscillatory‐ and sector‐zoned garnets record cyclic (?) rapid thrusting in central Nepal

Diagenetic Self-Organization and Stochastic Resonance in a Model of Limestone-Marl Sequences

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