This book would not have been as it is without the trenchant editing of Heather Godwin, nor without the punctilious attentions of Stuart Proffitt. I owe them both a great debt. I sincerely thank Robin Cocks and Neale Monks for acting as scientific readers, and for commenting on sundry facts. Claire Mellish kindly drew two of the diagrams. I particularly thank Chris Stringer, Theya Molleson and Robert Kruszynski for anthropological advice. Many friends and colleagues helped me by providing illustrations and advice (they carry no responsibility if I did not heed the latter).

This paper describes a methodology of translating mineral deposit models into flexible probabilistic structures based on (1) extraction of ore components (fluids, metals, and ligands) from crustal or mantle sources or both, (2) fluid- or melt-assisted transport of ore components from source to trap zones, (3) formation of trap zones (i.e., effective melt or fluid channels) that can focus melt or fluid migration and accommodate large amounts of metal, and (4) operation of the physicochemical processes that promote and sustain the deposition of metal from fluids or melts passing through a particular trap site.

1. D 2113 – 99. Standard Practice for Rock Core Drilling and Sampling of Rock for Site Investigation

2. D 2216 – 98. Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

3. D 2664 – 95a. Standard Test Method for Triaxial Compressive Strength of Undrained Rock Core Specimens Without Pore Pressure Measurements

4. D 2845 – 00. Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic Constants of Rock

5. D 2936 – 95 (Reapproved 2001)e1. Standard Test Method for Direct Tensile Strength of Intact Rock Core Specimens