Abstract

URBANI, Franco; GRANDE, Sebastián; GODDARD, Donald  and  MENDI, David. Review of the geology, mining and history of the san jacinto mercury deposit, baragua range, lara state, venezuela . Rev. Fac. Ing. UCV [online]. 2012, vol.27, n.2, pp.39-51. ISSN 0798-4065.

The only important mercury (cinnabar) mineralization in Venezuela is San Jacinto located to the northeast of the city of Carora, Lara State. It was discovered in the early twentieth century and mined between 1941 and 1942, producing about four metric tons of Hg. During 1941-1942 and 1968-1970, the site was studied in detail, and it was found that the ore is located in fractured sandstone layers of the Matatere Formation, but the high degree of post-mineralization faulting caused a lack of continuity. This is an hydrothermal (epithermal) deposit similar to Almaden, Spain, but of a much smaller scale. The primary Hg is located in the structure of the minerals of mafic and ultramafic rocks, where it is mobilized by hydrothermal solutions to be precipitated in the fractured layers of sandstone and graywacke of the Matatere Formation. The mineralized zone is limited to about two hectares, where the layers most enriched in cinnabar were exploited in 1941- 1942. Currently the site has no commercial value but it is considered of mineralogical and academic interest, as well as a place suitable for geological field-trips.

Keywords : Hidrothermalism; Cinnabar; Idrialite; Lara nappes; Matatere Formation.