philosophy with which to guide mineral exploration through the challenging decades ahead. Once already, in the early 1960s, a call for change had been heard (Ref. 30 in Chapter 1), when it became obvious that the prospecting methods of yesteryear, so successful in the past, could not keep up with the rapidly growing demand for minerals of the postwar period. The answer, a massive introduction of sophisticated geophysical and geochemical technologies backed by new geo­ logical models, proved spectacularly successful throughout the 1960s and the 1970s. But for both economic and technological reasons, the brisk pace of the last two decades has considerably slowed down in the early 1980s, as if a new threshold has been reached.