By Timothy J. Killeen Mining and energy companies invest in the Amazon because it is profitable. Opportunities are large because of geology, but development is costly due to the region’s isolation and lack of infrastructure. The decision to pursue a mineral exploitation project depends on several factors, but there are two primary technical criteria: (a) the richness of the mineral deposit, which determines the cost of extraction; and (b) the volume of the geological formation, which determines the productive lifetime of a mine or oil and gas field. Taken together, these two factors allow inve…