Earth Sciences 4432A/B Lecture Notes - Lecture 10: Peraluminous Rock, Peralkaline Rock, Carbonatite
13 Apr 2016
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Document Summary
Rare element deposits consists of a poorly defined group of elements. At different periods of time this has consisted of mo, w, v, u, ree, ta, sn, zr. Rare metal and strategic metal deposits essentially are synonymous with rare element deposits. An initial question that can be asked is. Are rare elements/metals rare? the answer is no. Figure 10-1 shows the abundances of metals in the upper continental crust relative to 106 moles of si (the only element more abundant that si in the earth"s crust is o). The major rock forming elements, al, na, k, c, fe, mg are, not surprisingly the most abundant, however, the ree, zr, nb, sn have similar crustal abundances as the base metals (cu, pb, zn). The rarest metals are te, re and precious metals (au and pge, platinum group elements). The rare elements" a typically at the 1 to 200 ppm, compared to cu-pb-zn, 17-67 ppm and au, 0. 0015 ppm and pt,
