Best of Luck All27 Sep 2017 07:47
Zenith Zacatecas ;
The
Zacatecas brine targets are considered by the Company to be most similar to those hosted in the immature salt lake
systems such as at Clayton Valley (host to the USA’s only lithium brine operation, Silver Peak in Nevada where the
lithium brines aquifers are stratified and occur in specific aquifers towards the deeper portions of the host basins
(Figure 2). Lithium brine projects can be subdivided into two broad deposit types, depending on the salt lake/salt basin
(salar) characteristics (Houston et al., 2011):
• Mature salars (those containing extensive thicknesses – often hundreds of meters - of halite (salt), such as those in
the Argentina and Chile- the Salar de Atacama, and the FMC Hombre Muerto operation). These Mature salt
dominated salars are characterized by having high permeability and specific yields (to a maximum of ~ 15 % Sy) near
surface, with the porosity and permeability decreasing rapidly with depth. In these salars the brine resource is
essentially between surface and 50 m below surface, as below this depth there is limited permeability in the salt,
due to salt recrystallization and cementation of fractures; and
• Immature salars, which are dominated by clastic sediments, with limited thicknesses of halite.-, such as those
known at Clayton Valley in Nevada. and Zenith’s model for Zacatecas Immature salars conversely have porosity and
permeability controlled by individual layers within the salar sequence. The porosity and permeability may continue
to depths of hundreds of meters in clastic salars.
A schematic cross section produced by the Servicio Geologico Mexicano (Figure 2a) located immediately west of
Zenith’s San Juan Salar at Zacatecas, shows interpreted deep (to 400m) Tertiary Lake Sediments beneath a calcrete
layer that may act as an aquaclude (water barrier), segregating ground water layers potentially of different salinity and
composition.
A comparative schematic section of the Clayton Valley basin is shown in Figure 2b at the same scale to highlight
similarities in the model, illustrating the near surface nature of the recent 15-27m deep auger holes at San Juan Salar.