Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture
<p>An innovative multi-analytical approach comprising mineralogical, minero-chemical, and microstructural analyses as well as an indirect machine learning-based statistical method was applied to investigate the mineralogy and the mineral chemistry of spinel subgroup minerals (SSMs) of differen...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-12-01
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| Series: | European Journal of Mineralogy |
| Online Access: | https://ejm.copernicus.org/articles/35/1091/2023/ejm-35-1091-2023.pdf |
| _version_ | 1797393403314438144 |
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| author | S. Fornasaro P. Comodi L. Crispini S. Zappatore A. Zucchini P. Marescotti |
| author_facet | S. Fornasaro P. Comodi L. Crispini S. Zappatore A. Zucchini P. Marescotti |
| author_sort | S. Fornasaro |
| collection | DOAJ |
| description | <p>An innovative multi-analytical approach comprising mineralogical, minero-chemical, and microstructural analyses as well as an indirect machine learning-based statistical method was applied to investigate the mineralogy and the mineral chemistry of spinel subgroup minerals (SSMs) of different ultramafic rocks from the high-pressure metaophiolites of the Voltri Massif (Central Liguria, NW Italy). The study was focused on the correlation between the compositional variations of SSMs and their texture, microstructure, and the degree of serpentinization of the host rock.</p>
<p>The SSM occurs with three main textures and microstructures linked to the progressive serpentinization and deformation of ultramafic rocks during the Alpine orogenic events: (i) Cr-spinel porphyroclasts with various degrees of recrystallization (up to magnetite porphyroblasts) within partially serpentinized peridotite and massive serpentinite; (ii) magnetite crystals associated with pseudomorphic and non-pseudomorphic serpentine textures (e.g., mesh, hourglass, ribbon, and interpenetrating textures) in partially serpentinized peridotite and massive serpentinites; and (iii) magnetite crystals re-oriented along the foliations developed in serpentine schist. The chemical composition of SSMs varies systematically within the textures and microstructures. These processes also affected the chemical composition of SSMs, the availability of Mn, Zn, Ni, and Co in solution, and their consequent incorporation in the lattice of chromian spinel due to olivine breakdown, the major repository of these elements in ultramafic rocks.</p>
<p>At a general scale, the trace and ultratrace variability is primarily related to the petrologic and tectonic evolution but, at a local scale, also the mineralogical, lithological, structural, and textural features correlated to the degree of serpentinization and/or deformation. These significantly influence the distribution and concentration of trace and ultratrace elements in SSMs. The results of the present work were also confirmed by an innovative indirect statistical method performed through the Weka Machine Learning Workbench.</p> |
| first_indexed | 2024-03-09T00:03:03Z |
| format | Article |
| id | doaj.art-76c7039e0b6743b4a77d525a5350478c |
| institution | Directory Open Access Journal |
| issn | 0935-1221 1617-4011 |
| language | English |
| last_indexed | 2024-03-09T00:03:03Z |
| publishDate | 2023-12-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | European Journal of Mineralogy |
| spelling | doaj.art-76c7039e0b6743b4a77d525a5350478c2023-12-12T14:29:14ZengCopernicus PublicationsEuropean Journal of Mineralogy0935-12211617-40112023-12-01351091110910.5194/ejm-35-1091-2023Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and textureS. Fornasaro0P. Comodi1L. Crispini2S. Zappatore3A. Zucchini4P. Marescotti5Dipartimento di Scienze della Terra, Università di Pisa, Via Santa Maria, 53, 56126, Pisa, ItalyDipartimento di Fisica e Geologia, Università di Perugia, Piazza dell’Università, 1, 06123, Perugia, Italy Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università di Genova, Corso Europa, 26, 16132, Genoa, ItalyDipartimento di Ingegneria Navale, Elettrica, Elettronica e delle Telecomunicazioni, Università di Genova, Via alla Opera Pia 11A, 16145, Genoa, ItalyDipartimento di Fisica e Geologia, Università di Perugia, Piazza dell’Università, 1, 06123, Perugia, Italy Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università di Genova, Corso Europa, 26, 16132, Genoa, Italy<p>An innovative multi-analytical approach comprising mineralogical, minero-chemical, and microstructural analyses as well as an indirect machine learning-based statistical method was applied to investigate the mineralogy and the mineral chemistry of spinel subgroup minerals (SSMs) of different ultramafic rocks from the high-pressure metaophiolites of the Voltri Massif (Central Liguria, NW Italy). The study was focused on the correlation between the compositional variations of SSMs and their texture, microstructure, and the degree of serpentinization of the host rock.</p> <p>The SSM occurs with three main textures and microstructures linked to the progressive serpentinization and deformation of ultramafic rocks during the Alpine orogenic events: (i) Cr-spinel porphyroclasts with various degrees of recrystallization (up to magnetite porphyroblasts) within partially serpentinized peridotite and massive serpentinite; (ii) magnetite crystals associated with pseudomorphic and non-pseudomorphic serpentine textures (e.g., mesh, hourglass, ribbon, and interpenetrating textures) in partially serpentinized peridotite and massive serpentinites; and (iii) magnetite crystals re-oriented along the foliations developed in serpentine schist. The chemical composition of SSMs varies systematically within the textures and microstructures. These processes also affected the chemical composition of SSMs, the availability of Mn, Zn, Ni, and Co in solution, and their consequent incorporation in the lattice of chromian spinel due to olivine breakdown, the major repository of these elements in ultramafic rocks.</p> <p>At a general scale, the trace and ultratrace variability is primarily related to the petrologic and tectonic evolution but, at a local scale, also the mineralogical, lithological, structural, and textural features correlated to the degree of serpentinization and/or deformation. These significantly influence the distribution and concentration of trace and ultratrace elements in SSMs. The results of the present work were also confirmed by an innovative indirect statistical method performed through the Weka Machine Learning Workbench.</p>https://ejm.copernicus.org/articles/35/1091/2023/ejm-35-1091-2023.pdf |
| spellingShingle | S. Fornasaro P. Comodi L. Crispini S. Zappatore A. Zucchini P. Marescotti Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture European Journal of Mineralogy |
| title | Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture |
| title_full | Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture |
| title_fullStr | Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture |
| title_full_unstemmed | Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture |
| title_short | Trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the Voltri Massif (NW Italy): the influence of microstructure and texture |
| title_sort | trace and ultratrace elements in spinel subgroup minerals of ultramafic rocks from the voltri massif nw italy the influence of microstructure and texture |
| url | https://ejm.copernicus.org/articles/35/1091/2023/ejm-35-1091-2023.pdf |
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