Introduction

Abstract

In the study of hydrothermal mineral deposits, the main objective is a basic understanding of ore genesis processes and the eventual building of models, which would best explain empirical observations, and enable deposit types to fit within the local and global geotectonic frameworks. The information required to achieve this must include: (1) origin and composition of the ore solutions; (2) physico-chemical conditions of solution, transport and deposition; (3) temperature, pressure and depth of ore formation; (4) source of the ore constituents; (5) metasomatic processes; (6) local geology and structure; (7) regional geology and tectonic setting; (8) origin and evolution of the magmas that give rise to hydrothermal processes. This information must be obtained through studies of geological characteristics and field relationships, mineralogy, trace and major element geochemistry of ores and wall rocks. The study of fluid inclusions provides data on the nature of the solutions, temperature, pressure and depth of ore formation, while stable isotope systematics helps in constraining the source of the fluids and tracing their movement through, and interaction with, the crust. Thus, it can be seen that the study of an ore deposit is a multidisciplinary effort. It requires that information be drawn from “outside” disciplines, such as physics, chemistry, mathematics and computer science, as well as the various branches of the Earth sciences.