Mineral system in the mantle section of forearc ophiolites
[eng] Ophiolitic sequences are the remnants of past oceanic lithosphere, including upper mantle and oceanic crust, that have been tectonically emplaced onto continental margins or volcanic arcs. Subduction-related ophiolites are the most common type of ophiolite formed in the so-called suprasubducti...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/222689 |
| Acceso en línea: | https://hdl.handle.net/2445/222689 http://hdl.handle.net/10803/695042 |
| Access Level: | acceso abierto |
| Palabra clave: | Peridotita Laterita Materials estratègics Roques ígnies Peridotite Laterite Strategic materials Igneous rocks |
| Sumario: | [eng] Ophiolitic sequences are the remnants of past oceanic lithosphere, including upper mantle and oceanic crust, that have been tectonically emplaced onto continental margins or volcanic arcs. Subduction-related ophiolites are the most common type of ophiolite formed in the so-called suprasubduction zone (SSZ). The mantle section of ophiolitic sequences is predominantly constituted by peridotites, mainly harzburgites with layers, dikes and/or sills of dunites, lherzolites, and pyroxenites. Ophiolitic peridotites are most relevant in the study of the composition of oceanic lithospheric mantle and in understanding large-scale geodynamic processes. However, ophiolitic peridotites also have a great potential at containing important economic resources of a suite of different metals, such as Cr, Ni, Co, Sc, Cu, Au, Ag, and platinum group elements (Ru, Os, Ir, Rh, Pt, Pd). In recent years, many national and international agreements have been signed to reduce, and eventually cut off, the emission of greenhouse gases, to slow the effects of climate change. However, the implementation of low-carbon energy technologies entails a considerable increase in the demand for minerals. In this regard, the mantle section of ophiolitic sequences has great potential to contribute to ease the demand of several metals catalogued as critical. The criticality of these metals lies in their essential role in modern technologies, economies, and national security, while their supply chains remain vulnerable to disruption. In this Ph.D. thesis, three different mineral systems hosted in the mantle section within the forearc region of a SSZ ophiolitic sequence are evaluated. The three studied mineral systems formed at different stages within the evolution of the intra-oceanic subduction setting, produced by the subduction of the proto-Caribbean lithosphere (inter-American Mesozoic ocean of Atlantic affinity formed after the breakup of Pangea) underneath the Caribbean lithosphere (of Pacific affinity), which generated the Cretaceous Caribbean island arc. The evaluation of the different deposits from a mineral system point of view considers all the geological processes that take place in the genesis and preservation of an ore deposit. This includes the mobilization, transport and accumulation of metals from a fertile source to an accumulation zone, together with all the processes responsible for preserving the deposit after its genesis. |
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