"With the size that Dr. Marsh knows this deposit will be (from the KNOWN root zone), the grade will only have to be .4% or so (which is the average grade in Arizona porphories apparently)"

Gryphon,

Given your access to Dr. Marsh, could you ask him to enlighten us on 'average grades' vis a vis 'tonnage'. Not so much in Arizona in general but specifically along the highly productive Copper Creek-Resolution-Bagdad porphyry trend where Kabba sits.

Along this mineralised trend Phelps Dodge is currently expanding its 200 million pounds of annual copper production capacity from the Bagdad Mine. Mercator Minerals is now producing at its Mineral Park Mine, which has proven and probable mill reserves of 437 million tons at a copper equivalent grade of 0.368%, and Rio Tinto has indicated over 1 billion tons of copper ore averaging over 1.5% copper at Resolution.

My understanding was that Bell was looking for significantly higher grades than 0.04%. According to a GoldLetter special report (Sept. '08):

"Bell targets for Kabba at least 500 million tons of oxide, enriched sulphide and primary sulphide ore at a mean grade of near 1% copper and 0.02% molybdenum, for gross in-situ metal value near $ 20 billion."

So how much approx. tonnage do we need for a lower grade of .4% to be economic?