Assessing the thermal history of ore-hosting rocks via low-temperature thermochronology is key to understand metal transfer and ore exhumation in mineral districts. Previous thermal models of the Segovia Batholith–host rock of the Segovia-Remedios Mining District in Colombia–need revision considering recent thermochronological data in the light of current geodynamic models of the Northwestern Andes region. This study reviews regional geo-thermochronological data of the Segovia Batholith and analyzes local petrographic and structural features in Gran Colombia Gold’s Segovia Project, the most productive of the Segovia-Remedios Mining District. One of the objectives aims at reconstructing the Segovia Batholith’s thermal history at regional and local scales using current data. The Segovia Batholith covers ~1600 km2 in the northern Colombian Central Cordillera, limited by the Otú Fault to the west and the Palestina Fault to the east. The time-temperature trajectory constructed here for this unit signals a Late Cretaceous-Paleocene exhumation event, which is contemporaneous with the activation of the Otú Fault and mineralization timing in the Segovia-Remedios Mining District; it is related to early uplift of the proto-Central Cordillera during a period of increased convergence between the Farallones, Caribbean, and South American plates. However, uplifting occurs asynchronously for different tectonic blocks. More rapid uplift west of the Otú Fault might have favored fluid migration from sub-cortical intrusions of the Antioquia Batholith towards the slow-exhuming Segovia Batholith to the east. At a local scale in the Segovia Project, the most prospective areas are located towards west close to the fluid source and permeable channel, between distensive areas of right-lateral shear with NW-SE-oriented compression, following R, R’ and P secondary structures. Furthermore, elevated thermal gradients in distensive areas towards NE facilitate effective metal transfer and can host higher ore grades.

0

  • Malo-Gonzalez, Andrea, Marín-Cerón, Maria Isabel; Noriega-Lodoño, Santiago; Restrepo-Moreno, Sergio
  • cmalogo@eafit.edu.co; mmarince@eafit.edu.co snoriegal@eafit.edu.co; sarestrepom@unal.edu.co;