Giant (and super-giant) metallic deposits are defined as those that store the trace metal (and some major metal like Fe, Al) equivalent in 1011 (1012) tons of continental crust in Clarke (mean crust content) concentration. Deposits of metallic ores that have very contrasting Clarke values (like Fe, Cu and Au) can be compared on geochemical basis, with political-economic and technologic factors minimized. Under these terms, there are now 1171 giant and 137 supergiant accumulations of 37 metals worldwide, contained in 915 deposits, as several deposits have two or more giant metal accumulations (Olympic Dam has 5).

As explained in Preface, this book is a selfcontained member of a broader knowledge system on the world's mineral deposits and their settings I have been developing and experimenting with for more than 40 years. It is a product of global firsthand information gathering in the field and "data mining" from the literature, followed by sorting and organization into interrelated sets searchable and accessible by the rapidly evolving techniques of modern information technology.

The giant outer planets—Jupiter, Saturn, Uranus, and Neptune (Figure 1.1)—are by far the largest planetary bodies in the solar system and together comprise 99.56% of the planetary mass. Although very far from the Earth, the enormous physical size of Jupiter and Saturn meant that these planets were easily visible to the ancients. However, the other two “giants”, Uranus and Neptune, are significantly smaller and so much farther from the Earth that they were unknown before the advent of telescopes, although Uranus is in fact just visible to the naked eye. Uranus was discovered by accident in 1781 by William Herschel (1738-1822) (later Sir William Herschel). Perturbations in the observed orbit of Uranus led John Couch Adams (1819-1892) and Urbain Jean Joseph Le Verrier (1811-1877) to independently predict the presence of a further planet, and Neptune was subsequently discovered close to its predicted position by Johann Gottfried Galle (1812-1910) in 1846. The mean observable properties of the outer planets are listed in Table 1.1. <...>

GIS Applications in Agriculture, Volume Four: Conservation Planning, edited by Tom Mueller and Gretchen F. Sassenrath, is the fourth volume in the book series GIS Applications in Agriculture, which is designed to enhance the application and use of geographic information systems (GISs) in agriculture by providing detailed GIS applications that are useful to scientists, educators, students, consultants, and farmers. The first volume, GIS Applications in Agriculture, edited by Francis J. Pierce and David Clay, was published by CRC Press in 2007. The second volume, GIS Applications in Agriculture: Nutrient Management for Improved Energy Efficiency, edited by David Clay and John Shanahan, and the third volume, GIS Applications in Agriculture: Invasive Species, edited by Sharon Clay, were published by CRC Press in 2011. While the newest book in this series, the idea of a book on conservation planning using GIS was identified in 2007 when the book series began. Intuitively, conservation planning through GIS applications should appeal to all conservationists who clearly understand that a key to achieving soil and water conservation is rooted in an understanding of the spatial and temporal variation in both soil and water resources and natural and human-induced forces that affect the quality and quantity of those resources. <...>