Publications

@article{murri_role_2022,

title = {The role of symmetry-breaking strains on quartz inclusions in anisotropic hosts: Implications for Raman elastic geobarometry},

author = {M. Murri and J. P. Gonzalez and M. L. Mazzucchelli and M. Prencipe and B. Mihailova and R. J. Angel and M. Alvaro},

url = {https://www.sciencedirect.com/science/article/pii/S0024493722001256},

doi = {10.1016/j.lithos.2022.106716},

issn = {0024-4937},

year  = {2022},

date = {2022-08-01},

urldate = {2022-08-01},

journal = {Lithos},

volume = {422-423},

pages = {106716},

abstract = {Raman elastic geobarometry for mineral host-inclusion systems is used to determine the strains acting on an inclusion still entrapped in its host by measuring its Raman wavenumber shifts which are interpreted through the phonon-mode Grüneisen tensors of the inclusion phase. The calculated inclusion strains can then be used in an elastic model to calculate the pressure and temperature conditions of entrapment. This method is applied frequently to host inclusion systems where the host is almost elastically isotropic (e.g. garnet) and the inclusion is elastically anisotropic (e.g. quartz and zircon). In this case, when the entrapment occurs under hydrostatic conditions the host will impose isotropic strains on the inclusion which in turn will develop non-hydrostatic stress. In this scenario the symmetry of the inclusion mineral is preserved and the strains in the inclusion can be measured via Raman spectroscopy using the phonon-mode Grüneisen tensor approach. However, a more complex situation arises when the host-inclusion system is fully anisotropic, such as when a quartz inclusion is entrapped within a zircon host, because the symmetry of the inclusion can be broken due to the external anisotropic strain field imposed on the inclusion by the host, which in turn will modify the phonon modes. We therefore calculated the strain states of quartz inclusions entrapped in zircon hosts in multiple orientations and at various geologically relevant pressure and temperature conditions. We then performed ab initio Hartree-Fock/Density Functional Theory (HF/DFT) simulations on α-quartz in these strain states. These HF/DFT simulations show that the changes in the positions of the Raman modes produced by strains that are expected for symmetry broken quartz inclusions in zircon are generally similar to those that would be seen if the quartz inclusions remained truly trigonal in symmetry. Therefore, the use of the trigonal phonon-mode Grüneisen tensor to determine the inclusion strains does not lead to geologically significant errors in calculated quartz inclusion entrapment pressures in zircon.},

keywords = {ab-initio, Crystallography, Density Functional Theory, DFT, Elastic anisotropy, Elastic thermobarometry, Raman spectroscopy, Raman thermobarometry},

pubstate = {published},

tppubtype = {article}

}

@article{angel_self-consistent_2021,

title = {A self-consistent approach to describe unit-cell-parameter and volume variations with pressure and temperature},

author = {R. Angel and M. Mazzucchelli and J. Gonzalez-Platas and M. Alvaro},

doi = {10.1107/S1600576721009092},

issn = {1600-5767},

year  = {2021},

date = {2021-12-01},

urldate = {2021-12-01},

journal = {Journal of Applied Crystallography},

volume = {54},

number = {6},

pages = {1621--1630},

abstract = {A method is presented for the self-consistent description of the variations of unit-cell parameters of crystals with pressure and temperature.},

keywords = {Crystallography, Elastic anisotropy, Elastic thermobarometry, Elasticity, thermodynamics},

pubstate = {published},

tppubtype = {article}

}

@article{gonzalez_elastic_2021,

title = {Elastic Geobarometry for Anisotropic Inclusions in Anisotropic Host Minerals: Quartz-in-Zircon},

author = {Joseph P. Gonzalez and Mattia L. Mazzucchelli and Ross J. Angel and Matteo Alvaro},

url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JB022080},

doi = {10.1029/2021JB022080},

issn = {2169-9356},

year  = {2021},

date = {2021-01-01},

urldate = {2021-01-01},

journal = {Journal of Geophysical Research: Solid Earth},

volume = {126},

number = {6},

pages = {e2021JB022080},

abstract = {Current models for elastic geobarometry have been developed with the assumption that the host and/or inclusion minerals are elastically isotropic. This assumption has limited applications of elastic thermobarometry to mineral inclusions contained in cubic quasi-isotropic host minerals (e.g., garnet). Here, we report a new elastic model that takes into account the anisotropic elastic properties and relative crystallographic orientation (RCO) of a host-inclusion system where both minerals are noncubic. This anisotropic elastic model can be used for host-inclusion elastic thermobarometric calculations provided that the RCO and elastic properties of both the host and inclusion are known. We then used this anisotropic elastic model to numerically evaluate the effects of elastic anisotropy and RCO on the strains and stresses developed in a quartz inclusion entrapped in a zircon host after exhumation from known entrapment P-T conditions to room P-T conditions. We conclude that the anisotropic quartz-in-zircon elastic model is suitable for elastic thermobarometry and may be widely applicable to crustal rocks. Our results demonstrate that isotropic elastic models cannot be used to determine the entire strain state of an elastically anisotropic inclusion contained in an elastically anisotropic host mineral, and therefore may lead to errors on estimated remnant inclusion pressures.},

keywords = {Elastic anisotropy, Elastic thermobarometry, FEM, Finite element method, Quartz, Zircon},

pubstate = {published},

tppubtype = {article}

}

@article{Morganti2020,

title = {A numerical application of the Eshelby theory for geobarometry of non-ideal host-inclusion systems},

author = {S. Morganti and Mattia Luca Mazzucchelli and M. Alvaro and A. Reali},

url = {http://link.springer.com/10.1007/s11012-020-01135-z},

doi = {10.1007/s11012-020-01135-z},

issn = {0025-6455},

year  = {2020},

date = {2020-02-01},

urldate = {2020-02-01},

journal = {Meccanica},

pages = {1--14},

abstract = {In the complex geodynamic processes occurring at convergent plate margins, rocks can be subducted at depth into the Earth experiencing metamorphism. A mineral inhomogeneity entrapped into another mineral, after exhumation to the Earth surface, will exhibit stress and strain fields different from those of the host because of the different thermoelastic properties. In the present paper, we propose a finite-element-based approach to determine the Eshelby and the relaxations tensors for any morphology of the inhomogeneity and for any crystallographic symmetry of the host. The proposed procedure can be directly applied in the framework of elastic geobarometry to estimate, on the basis of the Eshelby theory, the entrapment conditions (pressure and temperature) from the residual strain field measured in the inhomogeneity. This aspect represents a step forward to currently available models for geobarometry allowing the investigation of complex morphologies of the inhomogeneity in systems with general material anisotropy. We validate the proposed approach versus Eshelby analytical solutions available for spherical and ellipsoidal inclusions and we show the application to a real geological case of high pressure metamorphic rocks.},

keywords = {Elastic anisotropy, Elastic thermobarometry, Elasticity, FEM, Finite element method, Mechanics},

pubstate = {published},

tppubtype = {article}

}

@article{Campomenosi2020,

title = {Using polarized Raman spectroscopy to study the stress gradient in mineral systems with anomalous birefringence},

author = {N. Campomenosi and Mattia Luca Mazzucchelli and B. D. Mihailova and Ross John Angel and Matteo Alvaro},

url = {https://doi.org/10.1007/s00410-019-1651-x},

doi = {10.1007/s00410-019-1651-x},

issn = {14320967},

year  = {2020},

date = {2020-02-01},

urldate = {2020-02-01},

journal = {Contributions to Mineralogy and Petrology},

volume = {175},

number = {2},

pages = {1--16},

abstract = {Polarized Raman spectroscopy was applied to garnet hosts which exhibit anomalous birefringence around inclusions of zircon and quartz to elucidate the spatial distribution of the anisotropic strain fields in the vicinity of the host-inclusion boundary. We show that there is a direct relationship between the stress-induced birefringence and the Raman scattering generated by the fully symmetric phonon modes (the A1g modes in cubic crystals). Our experimental results coupled with selected finite element models show that the ratio between the measured Raman peak intensity collected in cross and parallel polarized scattering geometries of totally symmetric modes represents a useful tool to constrain the radial stress profile in the host around the inclusions. Further, we demonstrate how group-theoretical considerations and tensor analysis of the morphic effect (external-field-induced change of the symmetry) on the phonons and the optical properties of the host can help to derive useful information on the symmetry of the stress field. Finally, we show experimentally that, under the same amount of applied stress, this approach is more sensitive than the commonly used approach of measuring differences in phonon frequencies and provides better opportunities to map the spatial variations of strain. This approach is an alternative technique to study structural phenomena associated with anomalous birefringence in host crystals surrounding stressed inclusions and could be applied to other systems in which similar optical effects are observed.},

keywords = {Crystallography, Elastic anisotropy, Elasticity, Raman spectroscopy, Stress},

pubstate = {published},

tppubtype = {article}

}

@article{Alvaro2020,

title = {Fossil subduction recorded by quartz from the coesite stability field},

author = {M. Alvaro and M. L. Mazzucchelli and Ross John Angel and M. Murri and N. Campomenosi and M. Scambelluri and F. Nestola and A. Korsakov and A. A. Tomilenko and F. Marone and M. Morana},

url = {https://doi.org/10.1130/G46617.1},

doi = {10.1130/G46617.1},

issn = {19432682},

year  = {2020},

date = {2020-01-01},

urldate = {2020-01-01},

journal = {Geology},

volume = {48},

number = {1},

pages = {24--28},

abstract = {Metamorphic rocks are the records of plate tectonic processes whose reconstruction relies on correct estimates of the pressures and temperatures (P-T) experienced by these rocks through time. Unlike chemical geothermobarometry, elastic geobarometry does not rely on chemical equilibrium between minerals, so it has the potential to provide information on overstepping of reaction boundaries and to identify other examples of non-equilibrium behavior in rocks. Here we introduce a method that exploits the anisotropy in elastic properties of minerals to determine the unique P and T of entrapment from a single inclusion in a mineral host. We apply it to preserved quartz inclusions in garnet from eclogite xenoliths hosted in Yakutian kimberlites (Russia). Our results demonstrate that quartz trapped in garnet can be preserved when the rock reaches the stability field of coesite (the high-pressure and hightemperature polymorph of quartz) at 3 GPa and 850 °C. This supports a metamorphic origin for these xenoliths and sheds light on the mechanisms of craton accretion from a subducted crustal protolith. Furthermore, we show that interpreting P and T conditions reached by a rock from the simple phase identification of key inclusion minerals can be misleading.},

keywords = {Deviatoric stress, Elastic anisotropy, Elastic thermobarometry, petrology, Raman thermobarometry, Single-crystal X-ray diffraction},

pubstate = {published},

tppubtype = {article}

}

@article{Mazzucchelli2019,

title = {Elastic geobarometry for anisotropic inclusions in cubic hosts},

author = {Mattia Luca Mazzucchelli and A. Reali and S. Morganti and Ross John Angel and Alvaro M},

url = {https://doi.org/10.1016/j.lithos.2019.105218},

doi = {10.1016/j.lithos.2019.105218},

issn = {00244937},

year  = {2019},

date = {2019-10-01},

urldate = {2019-10-01},

journal = {Lithos},

pages = {105218},

keywords = {Deviatoric stress, Elastic anisotropy, Elastic thermobarometry, FEM, Finite element method},

pubstate = {published},

tppubtype = {article}

}

@article{Campomenosi2018,

title = {How geometry and anisotropy affect residual strain in host-inclusion systems: Coupling experimental and numerical approaches},

author = {Nicola Campomenosi and Mattia Luca Mazzucchelli and Boriana Mihailova and Marco Scambelluri and Ross John Angel and Fabrizio Nestola and Alessandro Reali and Matteo Alvaro},

url = {https://pubs.geoscienceworld.org/msa/ammin/article/103/12/2032/567206/How-geometry-and-anisotropy-affect-residual-strain},

doi = {10.2138/am-2018-6700CCBY},

issn = {0003-004X},

year  = {2018},

date = {2018-12-01},

urldate = {2018-12-01},

journal = {American Mineralogist},

volume = {103},

number = {12},

pages = {2032--2035},

keywords = {Elastic anisotropy, Elastic thermobarometry, Elasticity, Experiments, Raman spectroscopy},

pubstate = {published},

tppubtype = {article}

}

@article{murri_raman_2018,

title = {Raman elastic geobarometry for anisotropic mineral inclusions},

author = {Mara Murri and Mattia Luca Mazzucchelli and Nicola Campomenosi and Andrey V. Korsakov and Mauro Prencipe and Boriana D. Mihailova and Marco Scambelluri and Ross John Angel and Matteo Alvaro},

url = {https://doi.org/10.2138/am-2018-6625CCBY},

doi = {10.2138/am-2018-6625CCBY},

issn = {0003004X},

year  = {2018},

date = {2018-11-01},

urldate = {2018-11-01},

journal = {American Mineralogist},

volume = {103},

number = {11},

pages = {1869--1872},

keywords = {ab-initio, Density Functional Theory, Deviatoric stress, DFT, Elastic anisotropy, Elastic thermobarometry, metamorphic rocks, Raman spectroscopy, Raman thermobarometry},

pubstate = {published},

tppubtype = {article}

}