Active Components of the Subcontinental Lithospheric Mantle for Crustal Metallogenic Endowment in Off-Craton Regions
Ore deposits are rock volumes with anomalously high concentrations of selected elements that enable their extraction with economic profit. Metallic ore deposits may form in a wide spectrum of geological conditions, although they mostly occur in the magmatic and hydrothermal environments. Despite ext...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/348220 |
| Acceso en línea: | http://hdl.handle.net/10261/348220 |
| Access Level: | acceso abierto |
| Palabra clave: | Subcontinental lithospheric mantle Peridotite xenoliths Base-metal sulfides Platinum-group minerals Metal nanoparticles Chalcophile elements Re-Os isotopes Magmatic-hydrothermal ore deposits Manto litosférico subcontinental Xenolitos de peridotitas Sulfuros de metales base Minerales del grupo del platino Nanopartículas de metales Elementos calcófilos Isotopos de Re-Os Depósitos minerales magmáticohidrotermales |
| Sumario: | Ore deposits are rock volumes with anomalously high concentrations of selected elements that enable their extraction with economic profit. Metallic ore deposits may form in a wide spectrum of geological conditions, although they mostly occur in the magmatic and hydrothermal environments. Despite extensive investigation aimed to clarify the genesis and distribution of magmatichydrothermal ores, major controversies still concern the processes that drive the transfer and storage of metals from background levels in their source region to exploitable amounts in the crust. A key unresolved aspect regards whether the ore-productive magmas inherit their metallogenic fertility from pre-enriched domains of the mantle source, or they attain high metal concentrations due to favorable fractionation conditions during magma percolation and ascent. This issue is especially important for targeting mineral camps, as it constrains the specific geological conditions and environments that enhance the metallogenic endowment of the continental crust. To this regard, a better knowledge of the mechanisms and repositories that control the mobility and storage of metals in mantle rocks and magmas is essential. The general aim of this Ph.D. thesis is to assess the geological factors that govern the mobilization, transport, and concentration of chalcophile metals in the subcontinental lithospheric mantle (SCLM), emphasizing their impacts on the formation and distribution of magmatic-hydrothermal ore deposits in the overlying crust. To achieve this main goal, the thesis investigates the mineralogy, geochemistry and petrology of mantle peridotite xenoliths and associated volcanic rocks from mineralized regions in Central Mexico and Southeast Spain, focusing on base-metal sulfides (BMS), platinum-group minerals (PGM) and nano-tomicrometer- sized metal-rich particles as mineralogical-geochemical tracers of the behavior of precious and semi-metals in the SCLM. For this purpose, this study combines traditional analytical methods (e.g., transmitted/reflected light optical microscopy, scanning electron microscopy, electron microprobe analysis) with advanced techniques for the in-situ characterization of minerals (e.g., laser ablation-(multicollector) inductively coupled plasma-mass spectrometry, highresolution transmission electron microscopy). |
|---|