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Relevant bibliographies by topics / Calcite twins

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Journal articles

Academic literature on the topic 'Calcite twins'

Author: Grafiati

Published: 25 May 2024

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Journal articles on the topic "Calcite twins"

1

Lacombe, Olivier, Camille Parlangeau, Nicolas E. Beaudoin, and Khalid Amrouch. "Calcite Twin Formation, Measurement and Use as Stress–Strain Indicators: A Review of Progress over the Last Decade." Geosciences 11, no. 11 (2021): 445. http://dx.doi.org/10.3390/geosciences11110445.

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Mechanical twins are common microstructures in deformed calcite. Calcite twins have been used for a long time as indicators of stress/strain orientations and magnitudes. Developments during the last decade point toward significant improvements of existing techniques as well as new applications of calcite twin analysis in tectonic studies. This review summarises the recent progress in the understanding of twin formation, including nucleation and growth of twins, and discusses the concept of CRSS and its dependence on several factors such as strain, temperature and grain size. Classical and recent calcite twin measurement techniques are also presented and their pros and cons are discussed. The newly proposed inversion techniques allowing for the use of calcite twins as indicators of orientations and/or magnitudes of stress and strain are summarized. Benefits for tectonic studies are illustrated through the presentation of several applications, from the scale of the individual tectonic structure to the continental scale. The classical use of calcite twin morphology (e.g., thickness) as a straightforward geothermometer is critically discussed in the light of recent observations that thick twins do not always reflect deformation temperature above 170–200 °C. This review also presents how the age of twinning events in natural rocks can be constrained while individual twins cannot be dated yet. Finally, the review addresses the recent technical and conceptual progress in calcite twinning paleopiezometry, together with the promising combination of this paleopiezometer with mechanical analysis of fractures or stylolite roughness.

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2

Parlangeau, Camille, Alexandre Dimanov, Olivier Lacombe, Simon Hallais, and Jean-Marc Daniel. "Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development." Solid Earth 10, no. 1 (2019): 307–16. http://dx.doi.org/10.5194/se-10-307-2019.

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Abstract. E-twinning is a common plastic deformation mechanism in calcite deformed at low temperature. Strain rate, temperature and confining pressure have negligible effects on twinning activation which is mainly dependent on differential stress. The critical resolved shear stress (CRSS) required for twinning activation is dependent on grain size and strain hardening. This CRSS value may obey the Hall–Petch relation, but due to sparse experimental data its actual evolution with grain size and strain still remains a matter of debate. In order to provide additional constraints on twinning activation and development, new mechanical tests were carried out at room temperature on unconfined single crystals of calcite, with different sizes and crystallographic orientations. Uniaxial deformation was performed at a controlled displacement rate, while the sample surface was monitored using optical microscopy and a high-resolution CCD (charge-coupled device) camera. The retrieved macroscopic stress–strain behavior of the crystals was correlated with the surface observations of the deformation process. Results show (1) the onset of crystal plasticity with the activation of the first isolated mechanical twins during the strain hardening stage, and (2) the densification and thickening of twin lamellae during the steady-state flow stress stage. Such thickening of twin lamellae at room temperature emphasizes that calcite twin morphology is not controlled solely by temperature. The different values for the CRSS obtained for the activation of isolated twins and for the onset of twin densification and thickening raises questions regarding the appropriate value to be considered when using calcite twin data for stress inversion purposes.

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3

Schuster, Roman, Gerlinde Habler, Erhard Schafler, and Rainer Abart. "Intragranular deformation mechanisms in calcite deformed by high-pressure torsion at room temperature." Mineralogy and Petrology 114, no. 2 (2020): 105–18. http://dx.doi.org/10.1007/s00710-019-00690-y.

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AbstractPolycrystalline calcite was deformed to high strain at room-temperature and confining pressures of 1–4 GPa using high-pressure torsion. The high confining pressure suppresses brittle failure and allows for shear strains >100. The post-deformation microstructures show inter- and intragranular cataclastic deformation and a high density of mechanical e$$ \left\{01\overline{1}8\right\} $$011¯8 twins and deformation lamellae in highly strained porphyroclasts. The morphologies of the twins resemble twin morphologies that are typically associated with substantially higher deformation temperatures. Porphyroclasts oriented unfavorably for twinning frequently exhibit two types of deformation lamellae with characteristic crystallographic orientation relationships associated with calcite twins. The misorientation of the first deformation lamella type with respect to the host corresponds to the combination of one r$$ \left\{10\overline{1}4\right\} $$101¯4 twin operation and one specific f$$ \left\{01\overline{1}2\right\} $$011¯2 or e$$ \left\{01\overline{1}8\right\} $$011¯8 twin operation. Boundary sections of this lamella type often split into two separated segments, where one segment corresponds to an incoherent r$$ \left\{10\overline{1}4\right\} $$101¯4 twin boundary and the other to an f$$ \left\{01\overline{1}2\right\} $$011¯2 or e$$ \left\{01\overline{1}8\right\} $$011¯8 twin boundary. The misorientation of the second type of deformation lamellae corresponds to the combination of specific r$$ \left\{10\overline{1}4\right\} $$101¯4 and f$$ \left\{01\overline{1}2\right\} $$011¯2 twin operations. The boundary segments of this lamella type may also split into the constituent twin boundaries. Our results show that brittle failure can effectively be suppressed during room-temperature deformation of calcite to high strains if confining pressures in the GPa range are applied. At these conditions, the combination of successive twin operations produces hitherto unknown deformation lamellae.

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4

Mirijam, Vrabec, Rogan Šmuc Nastja, and Vrabec Marko. "Calcite deformation twins in Pohorje marbles." Geologija 61, no. 1 (2018): 73–84. http://dx.doi.org/10.5474/geologija.2018.005.

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5

Németh, Péter. "Diffraction Features from (101¯4) Calcite Twins Mimicking Crystallographic Ordering." Minerals 11, no. 7 (2021): 720. http://dx.doi.org/10.3390/min11070720.

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During phase transitions the ordering of cations and/or anions along specific crystallographic directions can take place. As a result, extra reflections may occur in diffraction patterns, which can indicate cell doubling and the reduction of the crystallographic symmetry. However, similar features may also arise from twinning. Here the nanostructures of a glendonite, a calcite (CaCO3) pseudomorph after ikaite (CaCO3·6H2O), from Victoria Cave (Russia) were studied using transmission electron microscopy (TEM). This paper demonstrates the occurrence of extra reflections at positions halfway between the Bragg reflections of calcite in 0kl electron diffraction patterns and the doubling of d104 spacings (corresponding to 2∙3.03 Å) in high-resolution TEM images. Interestingly, these diffraction features match with the so-called carbonate c-type reflections, which are associated with Mg and Ca ordering, a phenomenon that cannot occur in pure calcite. TEM and crystallographic analysis suggests that, in fact, (101¯4) calcite twins and the orientation change of CO3 groups across the twin interface are responsible for the extra reflections.

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6

Rutter, Ernest, David Wallis, and Kamil Kosiorek. "Application of Electron Backscatter Diffraction to Calcite-Twinning Paleopiezometry." Geosciences 12, no. 6 (2022): 222. http://dx.doi.org/10.3390/geosciences12060222.

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Electron backscatter diffraction (EBSD) was used to determine the orientation of mechanically twinned grains in Carrara marble experimentally deformed to a small strain (≤4%) at room temperature and at a moderate confining pressure (225 MPa). The thicknesses of deformation twins were mostly too small to permit determination of their orientation by EBSD but it proved possible to measure their orientations by calculating possible twin orientations from host grain orientation, then comparing calculated traces to the observed twin traces. The validity of the Turner & Weiss method for principal stress orientations was confirmed, particularly when based on calculation of resolved shear stress. Methods of paleopiezometry based on twinned volume fraction were rejected but a practical approach is explored based on twin density. However, although twin density correlates positively with resolved shear stress, there is intrinsic variability due to unconstrained variables such as non-uniform availability of twin nucleation sites around grain boundaries that imposes a limit on the achievable accuracy of this approach.

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7

Lacombe, Olivier. "Calcite Deformation Twins: From Crystal Plasticity to Applications in Geosciences." Geosciences 12, no. 7 (2022): 280. http://dx.doi.org/10.3390/geosciences12070280.

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8

Côté, A. S., R. Darkins, and D. M. Duffy. "Deformation twinning and the role of amino acids and magnesium in calcite hardness from molecular simulation." Physical Chemistry Chemical Physics 17, no. 31 (2015): 20178–84. http://dx.doi.org/10.1039/c5cp03370e.

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We employ classical molecular dynamics to calculate elastic properties and to model the nucleation and propagation of deformation twins in calcite, both as a pure crystal and with magnesium and aspartate inclusions.

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9

González-Casado, José M., and Carmen Garcı́a-Cuevas. "Calcite twins from microveins as indicators of deformation history." Journal of Structural Geology 21, no. 7 (1999): 875–89. http://dx.doi.org/10.1016/s0191-8141(99)00081-4.

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10

Kang, Seong-Seung, Jun-Mo Kim, and Bo-An Jang. "Paleostress fields from calcite twins in the Pyeongan Supergroup, South Korea." Island Arc 14, no. 2 (2005): 137–49. http://dx.doi.org/10.1111/j.1440-1738.2005.00462.x.

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