Yep...I cataloged some of those papers today...They were just learning how much they could learn via different types of film, and had testing areas in Georgia, the Black Hills, and in Oregon and Arizona where they were trying out spectral analysis, pictures taken at different scales, early computer modeling, and various other things. Pretty neat, although I don't have time to read these things in depth. They were playing with pics taken by the Apollo program, high altitude and lower altitude aerial photography, experimenting with sampling, and various other things. We've come a long way since those days, but they were really pioneers in this type of remote sensing.
One of the things that plants can tell you, by multi-spectral analysis, is the mineral health and wealth of the places they are growing.
We'll have to make do, in our quest, with direct mineral observations, but we'll try some experimental radar and X-ray techniques.