Ann: Cauchari Drilling Update, page-7

As tootellgeorge tried to say, they have plenty for their current needs. They have a fondness for saying things like
A very large resource of +40 years at current production which is open at depth and laterally
I prefer it when they say that phase 1 uses just 15% of the current resource over 40 years.

There has been some speculation as to the exploration upside size at Olaroz. Back in 2014 they came out with this announcement and it probably answers your question about the presence of thick sands at depth... http://www.orocobre.com/news/mdocs-...oz_deepbrine/?mdocs-file=2387&mdocs-url=false

Olaroz Project Large Exploration Target Defined Beneath Current Resource
 A final production bore, P302 drilled to 323m, has been commissioned bringing the potential pumping rate to over 230l/s compared to long term requirements of 180l/s.
 P302 intersected a thick sand unit >100m thick, beneath the current resource. This unit was also intersected in an earlier 300m hole P301, 1 kilometre north. Geological interpretation suggests this sand unit maybe continuous beneath a significant area of the salar.
 The exploration target corresponding to this sand unit is between 1.6 and 7.5 million tonnes of lithium carbonate equivalent between 197m and 323m depth. There is the potential for additional brine from 323m to the bottom of the basin which geophysical surveys suggest is up to 600m deep and additional targets to the north and the south of the exploration target area.
 The deeper sand unit has the characteristics to support high volume brine production, with lithium concentrations and chemistry comparable to other operating wells. This will significantly reduce the capital cost for additional brine supply and pipeline systems which will be needed for the first expansion at Olaroz.

The announcement is worth a read... and then to reflect that the current resource is defined to just 197m depth.

A very large resource of +40 years at current production which is open at depth and laterally
Yes, indeed...