American Scientist

Undiscovered Petroleum and Mineral Resources: Assessment and Controversy. Lawrence J. Drew. 210 pp. Plenum Press, 1997. $59.50.

Although most scientists never experience controversies as significant or fights as bitter as those over the assessment of undiscovered mineral resources, all will see parallels to their own professional lives in this story told by Lawrence Drew. Nonscientists will gain an understanding of how the advance of science is constrained by the frailties of scientists and the whims of the environment in which we work. From his perspective as a quantitative geologist at the United States Geological Survey (USGS), Drew interweaves the technical with the human strands to tell of the development of statistical methods for estimating undiscovered earth resources.

Resource assessments are controversial in the political realm because they always offend some special interest. For example, both conventional and unconventional undiscovered natural gas resources were estimated in a 1980 assessment by the USGS. When a new assessment limited to conventional resources was prepared in 1988, it appeared superficially that undiscovered resources had declined by 40 percent. Politicians were not pleased. The American gas industry had lobbied to have both categories of resources estimated. Environmentalists saw natural gas as the carbon-based fuel of choice. And the Reagan administration promoted natural gas as a substitute for imported oil to improve economic and military security. Misreading of the 1988 report and the desire of these interests for a larger resource base resulted in harsh criticism of USGS methods.

Controversy results within the profession because the deterministic mindset of most geologists is challenged by the new statistical methods. Some very vocal and determined deterministic geologists have opposed applying statistical methods to estimating undiscovered metal resources. They believe that deposits cannot be classified into geologically similar groups within which statistical prediction is possible, although the validity of this approach is confirmed by the analyses themselves. Drew observes that geologists are deterministic by nature and training.

A particularly acrimonious dispute is chronicled in the last chapter, "The Charge Was Scientific Fraud." As Drew sees it, an unprofessional attack on statistical assessment methods, particularly by one USGS geologist and National Academy of Sciences member, has been the result of a complex series of events beginning in the late 1970s and continuing today. He details the effects of factors such as a greater emphasis in the USGS on producing products useful in the near term, concern for the environment, actions of nongovernmental organizations, statistical versus deterministic viewpoints, personalities of geologists, management styles and budget constraints. As a result of the attack, a review of statistical assessment methods was made by an outside organization in 1992. It found the methods to be sound and correctly applied.

Although the human aspects will be of interest to more readers, the discussion of technical matters occupies more of the book. Drew does an excellent job of explaining the fundamental concepts without recourse to mathematics. The geometric distribution of field sizes, concepts of field growth and field mortality, and grade-versus-tonnage curves for metallic deposits are clearly explained. Several pilot projects are detailed, as are their roles in the development of the methods. The numerous maps and graphs are easily understood and enhance the text.

Drew's revelation of the human side of the scientific enterprise will be interesting to scientists and an educational experience for anyone unfamiliar with the sometimes unseemly goings-on among scientists. Geologists in particular will find the technical discussion illuminating. This is a well-written and informative book, and that last chapter is a real page turner!—Steve Collins, Consulting Geologist, Nitro, WV