Zones appear to be numbered differently depending on location...

Zones appear to be numbered differently depending on location and depth.
Other parts of the basin historically have zone 33 at a depth of 7270 feet.
IM starting to wonder if GB2 was drilled deep enough and that the target depth at that location drilled to ,was actually zone 19 or 29 and not zone 31 as that part of the basin is quite deep.
Another theory is that at the current location ,being that the brines are at a shallower depth ,is that some Zones have joined as one zone being the reason why the grades have been historically reported as higher grades.
So in other words IM speculating that as the basin deepens the higher grade zones split up into other zones making each zone a lower grade.
If my thinking is correct ,this current drill hole could be the jackpot we have all been waiting for.
The November 2017 International Lithium Graphite and Cobalt Conference on page 18 is where IM sourcing the depth information from along with previously announced drill results.