2) on-site subsurface olivine basalt quantity

Altogether at Chiripa TAP excavated an area of approximately 496 m$^{2}$, and recovered 4979 g of RMT 61 and 65 from those units. The same units yielded 383 g of the material from the surface. This produces a surface density of 0.77g/m$^{2}$, or 7.7 kg/ha, significantly lower than that calculated for the peninsula as a whole in step 1 (24.2 kg/ha), and a surface/subsurface ratio of 0.08. Using this ratio produces an estimate of 19875 kg or 19.9 metric tons of on-site subsurface RMT 61 and 65 on the Taraco Peninsula.

It may be that the surface of Chiripa has been relatively more cleared than the surface of other sites. This is probably the case, since some of the areas we excavated included a soccer field and the surface of the Chiripa mound. These would necessarily have fewer materials evident on the surface than would a plowed field. We may therefore use the peninsula-wide average surface density of 24.3 kg/ha to retrodict a total surface weight of 1200.3 g for the 496 m$^{2}$ excavated at Chiripa. This produces a surface/subsurface ratio of 0.24, and a total on-site subsurface estimate of 6625 kg (6.6 metric tons) for the whole Taraco Peninsula.

We may consider these numbers - 19.9 and 6.6 metric tons - as possible maximum and minimum values.