text: Geology 
  
  The silver and gold mineralisation is hosted 
  within tertiary-aged volcanic units at Arqueros 
  and Teterita, and in Paleozoic sediments at 
  Chimberos. The alteration and mineralisation 
  are all Miocene in age and associated with the 
  Cerros Bravos paleovolcano. 
  
  Mineralisation comprises two main compo- 
  nents. Silver-rich horizontal units termed 
  ‘mantos’ (Spanish for blanket) and a series of 
  near-vertical, cross-cutting gold-rich structures. 
  The mantos silver mineralisation is hosted by 
  vuggy silica within dacitic lapilli tuff. Mantos 
  occurs at Arqueros and Teterita where the 
  mineralising process has replaced horizontal 
  porous tuffs. At Chimberos, silver mineralisation 
  is hosted in vuggy silica hydrothermal breccia 
  superimposed on folded Paleozoic sediments. 
  Feasibility Study 
  
  The vertical gold-rich mineralisation, also charac- 
  terised by vuggy silica, is well-developed at 
  Arqueros. It has been interpreted as feeders for 
  mineralising fluids. Nonetheless, this style of 
  mineralisation has not yet been observed at 
  Teterita and is poorly preserved at Chimberos. 