My view is that a spodumene rock sample would have significantly...

My view is that a spodumene rock sample would have significantly less lithium than spodumene found in a pegmatite at depth. According to Greenbushes Lithium Operations NI43-101 Technical Report dated 15 June 2011 for Talison Lithium Limited, "Lithium is strongly leached in the weathering environment and is virtually absent in weathered pegmatite".

The Greenbushes NI43-101 report goes on to state, "While surface exploration has proven useful in locating pegmatite bodies, weathering and associated leaching means that economic lithium mineralisation does not occur at surface. Consequently, diamond and reverse circulation percussion drilling have been the primary tools in developing the lithium mineral resource."

In the near surface lateritic environments at Greenbushes, pegmatites are highly depleted in lithium near surface. At Greenbushes lithium production is limited to below the weathered zone and economic lithium was only discovered in the 1980s as a result of deeper drilling. The photographs from Argentina don't say a lot and it's difficult to see the degree of weathering but I assume the deep underground mining is due to similar weathering of lithium in surface pegmatites that is found at Greenbushes and elsewhere.