Publications

@article{gonzalez_first_2024,

title = {First evaluation of stiff-in-soft host–inclusion systems: experimental synthesis of zircon inclusions in quartz crystals},

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

url = {https://link.springer.com/10.1007/s00410-023-02081-1},

doi = {10.1007/s00410-023-02081-1},

issn = {0010-7999, 1432-0967},

year  = {2024},

date = {2024-02-01},

urldate = {2024-02-01},

journal = {Contributions to Mineralogy and Petrology},

volume = {179},

number = {2},

pages = {13},

abstract = {Quartz crystals with zircon inclusions were synthesized using a piston-cylinder apparatus to experimentally evaluate the use of inclusions in “soft” host minerals for elastic thermobarometry. Synthesized zircon inclusion strains and, therefore, pressures (Pinc) were measured using Raman spectroscopy and then compared with the expected inclusion strains and pressures calculated from elastic models. Measured inclusion strains and inclusion pressures are systematically more tensile than the expected values and, thus, re-calculated entrapment pressures are overestimated. These discrepancies are not caused by analytical biases or assumptions in the elastic models and strain calculations. Analysis shows that inclusion strain discrepancies progressively decrease with decreasing experimental temperature in the α-quartz field. This behavior is consistent with inelastic deformation of the host–inclusion pairs induced by the development of large differential stresses during experimental cooling. Therefore, inclusion strains are more reliable for inclusions trapped at lower temperature conditions in the α-quartz field where there is less inelastic deformation of the host–inclusion systems. On the other hand, entrapment isomekes of zircon inclusions entrapped in the β-quartz stability field plot along the α–β quartz phase boundary, suggesting that the inclusion strains were mechanically reset at the phase boundary during experimental cooling and decompression. Therefore, inclusions contained in soft host minerals can be used for elastic thermobarometry and inclusions contained in β-quartz may provide constraints on the P–T at which the host–inclusion system crossed the phase boundary during exhumation.},

keywords = {Elastic thermobarometry, Elasticity, Experiments, high-pressure, high-temperature, Quartz, Raman thermobarometry, Zircon},

pubstate = {published},

tppubtype = {article}

}

@article{campomenosi_using_2021,

title = {Using the elastic properties of zircon-garnet host-inclusion pairs for thermobarometry of the ultrahigh-pressure Dora-Maira whiteschists: problems and perspectives},

author = {Nicola Campomenosi and Marco Scambelluri and Ross J. Angel and Joerg Hermann and Mattia L. Mazzucchelli and Boriana Mihailova and Francesca Piccoli and Matteo Alvaro},

url = {https://doi.org/10.1007/s00410-021-01793-6},

doi = {10.1007/s00410-021-01793-6},

issn = {1432-0967},

year  = {2021},

date = {2021-04-01},

urldate = {2021-04-01},

journal = {Contributions to Mineralogy and Petrology},

volume = {176},

number = {5},

pages = {36},

abstract = {The ultrahigh-pressure (UHP) whiteschists of the Brossasco-Isasca unit (Dora-Maira Massif, Western Alps) provide a natural laboratory in which to compare results from classical pressure (P)–temperature (T) determinations through thermodynamic modelling with the emerging field of elastic thermobarometry. Phase equilibria and chemical composition of three garnet megablasts coupled with Zr-in-rutile thermometry of inclusions constrain garnet growth within a narrow P–T range at 3–3.5 GPa and 675–720 °C. On the other hand, the zircon-in-garnet host-inclusion system combined with Zr-in-rutile thermometry would suggest inclusion entrapment conditions below 1.5 GPa and 650 °C that are inconsistent with the thermodynamic modelling and the occurrence of coesite as inclusion in the garnet rims. The observed distribution of inclusion pressures cannot be explained by either zircon metamictization, or by the presence of fluids in the inclusions. Comparison of the measured inclusion strains with numerical simulations shows that post-entrapment plastic relaxation of garnet from metamorphic peak conditions down to 0.5 GPa and 600–650 °C, on the retrograde path, best explains the measured inclusion pressures and their disagreement with the results of phase equilibria modelling. This study suggests that the zircon-garnet couple is more reliable at relatively low temperatures (textless 600 °C), where entrapment conditions are well preserved but chemical equilibration might be sluggish. On the other hand, thermodynamic modelling appears to be better suited for higher temperatures where rock-scale equilibrium can be achieved more easily but the local plasticity of the host-inclusion system might prevent the preservation of the signal of peak metamorphic conditions in the stress state of inclusions. Currently, we cannot define a precise threshold temperature for resetting of inclusion pressures. However, the application of both chemical and elastic thermobarometry allows a more detailed interpretation of metamorphic P–T paths.},

keywords = {Elastic thermobarometry, Garnet, metamorphic rocks, petrology, Raman spectroscopy, Raman thermobarometry, Zircon},

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}

}