- Email: [email protected]
Prospecting in areas of desert terrain
343 volume, and more recent information on epithermal systems in general, as well as technical articles with additional data on many of these 14 deposits, I regret to say that this book does not receive a high priority on a recommended purchase list. Reference: Murowchick and Barnes, 1986. Marcasite precipitation from hydrothermal solutions. Geochim. Cosmochim. Acta, 50 (12): 2615-2629. C A R L A. K U E H N (University Park, PA, U.S.A.)
Prospecting in Areas of Desert Terrain. The Institution of Mining and Metallurgy, London, England, 1985, 283 pp., £ 28 (ca. US $45 ). Depending on whose definition one chooses to use, between 14 and 22 perent of the Earth's continental surface is classified as "desert." This constitutes an area ranging from 20 to 31 million km 2. From this standpoint alone, a book concerning strategy, planning, and execution of multidisciplinary mineral exploration programs in desert environments should be of some importance to explorationists in general asnd to exploration geochemists in particular. This book is a collection of 26 papers presented at the international conference, "Prospecting in areas of desert terrain," organized by the Institution of Mining and Metallurgy and the Ministry of Energy and Mines, Government of Morocco, with the cooperation of the Arab Organization for Mineral Resources. The conference was held in Rabat, Morocco, on April 14-17, 1985. As might be expected given the conference site, the deserts of northern Africa and Arabia receive the most attention: seven and six papers, respectively. The deserts of southern Africa and Australia are the focus of four and three papers, respectively, and those of Chile, northwest India, and Iran are each the location of one study. The three remaining papers in the volume discuss geophysical and geochemical instrumentation appropriate for arid regions and have no specific geographic focus. Fourteen of the papers are at least partially devoted to geochemical exploration. The exploration geochemist must deal with a number of problems when working in the desert. Logistics can be quite difficult in waterless, roadless, and uninhabited terrain. Secondary dispersion of pathfinder elements is generally limited in the poorly developed soils commonly found in arid climates. This factor may necessitate a higher sample density than would be needed in more humid areas. There is the ever-present problem of eolian contamination resulting in dilution of soil or stream sediments with barren, windblown material. Four methods that have been successful in combating the dilution problem are discussed in this volume: (1) separating and discarding the eolian
344 phase by sieving and retaining a relatively coarse fraction for analysis; (2) selectively concentrating metal-bearing phases according to density and magnetic properties; (3) using selective leach methods in areas of sufficient chemical dispersion; and (4) using biogeochemical methods. The one unifying theme throughout the book is the need to conduct a well planned orientation survey before embarking on full-scale geochemical exploration in desert terrain. Most of the papers are well written, although in a few instances, it is obvious that English is not the first language of the author. There are a few editorial deficiencies, particularly where illustrations are concerned, but these do not seriously detract from the quality of the papers. Although no real conceptual advances are presented here, most explorationists working in the desert would do well to spend a few hours with the book. The Second International Conference on Prospecting in Arid Terrain is scheduled to be held in Australia in April of 1988. DAVIDB. SMITH (Denver, CO, U.S.A.)
Contouring Geological Surfaces with the Computer, by Thomas A. Jones, David E. Hamilton, and Carlton R. Johnson. Computer Methods in the Geosciences Series, Van Nostrand Reinhold, New York, NY, 1986, 314 pp., US $37.95.
Contouring Geologic Surfaces with the Computer is a well-written, well-organized and highly informative book. This book has been written from a practical perspective and it is apparent that the authors have written it with the geoscientist in mind; it is one that I will keep on my book shelf for reference. Much of the book uses examples from the petroleum industry, but the techniques discussed are readily applicable to other disciplines within the geologic community. The first chapter, Computers, Contouring and Geologic Interpretation, is an overview of the application of the computer to geologic problems, and outlines the types of studies where this technology is appropriate. A general statement of the book's purpose, "an overview and supplement to acquaint the reader with the subject and not a user's manual", is also included. The second chapter, Contouring and Geologic Concepts, discusses fundamentals regarding contouring, stratigraphy, structure, and reservoir properties, establishing definitions, terminology and concepts used within the book. The concepts discussed in chapters 3 and 4 provide the foundations on which the rest of the book is built. Chapter 3, Input Data for Computer Mapping, discusses organization and editing of data along with general data calculations. Chapter 4, Simple Grids and Contour Maps, coves the definition and construc-
Prospecting in Areas of Desert Terrain. The Institution of Mining and Metallurgy, London, England, 1985, 283 pp., £ 28 (ca. US $45 ). Depending on whose definition one chooses to use, between 14 and 22 perent of the Earth's continental surface is classified as "desert." This constitutes an area ranging from 20 to 31 million km 2. From this standpoint alone, a book concerning strategy, planning, and execution of multidisciplinary mineral exploration programs in desert environments should be of some importance to explorationists in general asnd to exploration geochemists in particular. This book is a collection of 26 papers presented at the international conference, "Prospecting in areas of desert terrain," organized by the Institution of Mining and Metallurgy and the Ministry of Energy and Mines, Government of Morocco, with the cooperation of the Arab Organization for Mineral Resources. The conference was held in Rabat, Morocco, on April 14-17, 1985. As might be expected given the conference site, the deserts of northern Africa and Arabia receive the most attention: seven and six papers, respectively. The deserts of southern Africa and Australia are the focus of four and three papers, respectively, and those of Chile, northwest India, and Iran are each the location of one study. The three remaining papers in the volume discuss geophysical and geochemical instrumentation appropriate for arid regions and have no specific geographic focus. Fourteen of the papers are at least partially devoted to geochemical exploration. The exploration geochemist must deal with a number of problems when working in the desert. Logistics can be quite difficult in waterless, roadless, and uninhabited terrain. Secondary dispersion of pathfinder elements is generally limited in the poorly developed soils commonly found in arid climates. This factor may necessitate a higher sample density than would be needed in more humid areas. There is the ever-present problem of eolian contamination resulting in dilution of soil or stream sediments with barren, windblown material. Four methods that have been successful in combating the dilution problem are discussed in this volume: (1) separating and discarding the eolian
344 phase by sieving and retaining a relatively coarse fraction for analysis; (2) selectively concentrating metal-bearing phases according to density and magnetic properties; (3) using selective leach methods in areas of sufficient chemical dispersion; and (4) using biogeochemical methods. The one unifying theme throughout the book is the need to conduct a well planned orientation survey before embarking on full-scale geochemical exploration in desert terrain. Most of the papers are well written, although in a few instances, it is obvious that English is not the first language of the author. There are a few editorial deficiencies, particularly where illustrations are concerned, but these do not seriously detract from the quality of the papers. Although no real conceptual advances are presented here, most explorationists working in the desert would do well to spend a few hours with the book. The Second International Conference on Prospecting in Arid Terrain is scheduled to be held in Australia in April of 1988. DAVIDB. SMITH (Denver, CO, U.S.A.)
Contouring Geological Surfaces with the Computer, by Thomas A. Jones, David E. Hamilton, and Carlton R. Johnson. Computer Methods in the Geosciences Series, Van Nostrand Reinhold, New York, NY, 1986, 314 pp., US $37.95.
Contouring Geologic Surfaces with the Computer is a well-written, well-organized and highly informative book. This book has been written from a practical perspective and it is apparent that the authors have written it with the geoscientist in mind; it is one that I will keep on my book shelf for reference. Much of the book uses examples from the petroleum industry, but the techniques discussed are readily applicable to other disciplines within the geologic community. The first chapter, Computers, Contouring and Geologic Interpretation, is an overview of the application of the computer to geologic problems, and outlines the types of studies where this technology is appropriate. A general statement of the book's purpose, "an overview and supplement to acquaint the reader with the subject and not a user's manual", is also included. The second chapter, Contouring and Geologic Concepts, discusses fundamentals regarding contouring, stratigraphy, structure, and reservoir properties, establishing definitions, terminology and concepts used within the book. The concepts discussed in chapters 3 and 4 provide the foundations on which the rest of the book is built. Chapter 3, Input Data for Computer Mapping, discusses organization and editing of data along with general data calculations. Chapter 4, Simple Grids and Contour Maps, coves the definition and construc-