Deseado Massif

The Deseado Massif (Spanish: Macizo del Deseado) is a massif in southern Patagonia located in the Argentine province of Santa Cruz. On surface the massif is made up of Middle to Late Jurassic-aged felsic volcanic rocks. Analysis of mantle xenoliths reveals that the lithospheric mantle of Deseado Massif is about 2100 to 1000 million years old. As such el Deseado Massif is one of the oldest regions of Patagonia as it existed already in some form during the Paleo and Mesoproterozoic. In the Neoproterozoic the Deseado Massif together with the Falkland Islands formed part of the supercontinent Rodinia. Since then Deseado Massif has been next to the Falkland Islands.

The Deseado Massif contain valuable epithermal gold deposits. The richness of Deseado Massif in gold may stem from its ancient and enriched mantle lithosphere.Cerro Vanguardia and Manantial Espejo are among the gold mines in the massif.

...
Wikipedia