Late Variscan tectonic orogenic collapse as a trigger for Sn-W mineralizing systems. U-Pb ore geochronology across the Martinamor gneissic dome (Salamanca, Spain)
Regional tectonothermal evolution is a primary factor for many mineral deposits formation. Late orogenic gravitational collapse has been widely recognized across different orogens, including the Variscan belt. The Martinamor gneissic dome is a well constrained structure related to the late-Variscan...
| Autores: | , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/122983 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/122983 |
| Access Level: | acceso abierto |
| Palabra clave: | 553.3:551.24(460.187) U-Pb geochronology cassiterite and wolframite Gneissic dome Extensional detachment Central Iberian zone Variscan gravitational collapse Central Iberian Arc orocline Heat advection Iberian Massif Mineralogía (Geología) Geodinámica 2506.10 Yacimientos Minerales 2506.20 Geología Estructural |
| Sumario: | Regional tectonothermal evolution is a primary factor for many mineral deposits formation. Late orogenic gravitational collapse has been widely recognized across different orogens, including the Variscan belt. The Martinamor gneissic dome is a well constrained structure related to the late-Variscan orogenic collapse in the Iberian Massif. We have investigated Sn-W mineralization spatially related to the Martinamor dome by LA-ICP-MS U-Pb dating of cassiterite and wolframite, revealing a wide mineralization timespan of 40 Myr. Our results show: a) an early (338.1 ± 5.8 Ma), minor mineralization phase, (W-dominated), potentially related to Variscan compressive phases; b) a second, major stage which lasted from 324.1 ± 5.9 to 300.7 ± 5.4 Ma, which includes Sn-bearing pegmatites and Sn-W veins formed under the syn-collisional extensional collapse. Structural evidence highlights the role of extensional detachments in channeling mineralizing fluids and creating suitable traps under ductile and ductile–brittle conditions; it also explains the temporal and spatial distribution of the Sn-W vein-type mineralizations in the zone. Comparisons with other Variscan deposits in the Iberian Massif and European counterparts suggest a regional metallogenic cycle linked to late-Variscan extensional collapse, heat advection, and crustal partial melting processes. These findings underscore the Martinamor dome as a unique structure recording a protracted Variscan tectono-magmatic-metallogenic event, with implications for understanding Sn-W deposit formation in orogenic settings. |
|---|