Intrusion-related gold systems (IRGS) are a newly-defined (1999) deposit classification (based mainly on well-studied deposits in Alaska and Yukon) that is already mired in confusion, nomenclature uncertainty and misapplication. Increasingly, gold deposits are mis-assigned an IRGS classification because: 1) the nomenclature of intrusion-related gold models has been rapidly evolving; 2) the characteristics of the classification are broadly defined to include a wide range of deposit types that overlap with other gold deposit types; and 3) granitoid intrusions are common features of orogenic belts and are an obvious fluid source for any proximal gold occurrence. 

Количественная оценка минеральных ресурсов платины, палладия, золота, никеля и меди в неоткрытых месторождениях PGE в основных и ультраосновных расслоенных  интрузиях в Финляндии

Most of the known platinum group element (PGE) resources in Finland are in contact- and reef-type deposits in 2.45 Ga mafic-ultramafic layered intrusions. These intrusions also have the potential to contain the majority of possibly existing, yet undiscovered, PGE resources in Finland. The undiscovered Pt, Pd, Au, Ni, and Cu resources in contact- and reef-type deposits were estimated down to one kilometre depth using the three-part quantitative assessment method.

In recent years, there has been increasing interest from geoscientists in potassic igneous rocks. Academic geoscientists have been interested in their petrogenesis and their potential value in defining the tectonic setting of the terranes into which they were intruded, and exploration geoscientists have become increasingly interested in the association of these rocks with major epithermal gold and porphyry gold-copper deposits. Despite this current interest, there is no comprehensive textbook that deals with these aspects of potassic igneous rocks. 

Mineral exploration has long been an active pursuit of both individuals and mining companies in Ontario. In recent years there has been a resurgence of interest in prospecting by individuals as a full time occupation, but more especially as “weekend prospectors’’. Accordingly, it was thought appropriate to collect together the reported instances of mineralized fragments dislodged from their bedrock source so that the techniques of tracing such fragments to their source as well as the locations of known fragments would be available to those interested in mineral exploration. 

Uranium is a widespread commodity throughout the crystalline Bohemian Massif and the basins of its platform cover in the Czech Republic. Most uranium mined occurred in vein- and sandstone-type deposits that cluster in a number of districts within eight uranium regions. Small deposits and occurrences also occur isolated elsewhere in the country. $Figure 3.1 shows the uranium regions with districts and deposits and $Table 3.1 lists reported data of districts and deposits. Since uranium mining was resumed after World War II,74 deposits were mined in 6 districts and at several localities scattered throughout the country.

Since antiquity, gold has been valued for its scarcity, beauty, and resistance to corrosion. Gold is the best known of all native elements and the most likely to be found in a metallic state (Pough 1991). It is the universal standard of value and the common medium of exchange in world commerce (Koschmann and Bergendahl 1968). Gold is almost everywhere considered to be the symbol of everything precious and of enduring value because of the effort required to extract it from nature, and because of its scarcity relative to other metals (Petralia 1996; Merchant 1998). Gold was known and highly valued by the earliest civilizations:

The first edition of this book covered those subjects that I believed were fundamental to acquiring sufficient knowledge about the mining sector to invest in it with confidence. In doing this I dipped into a wide number of subjects and tried to extract the points and issues most relevant to successful investing. Since then the mining and metals sector has experienced a massive bull market and this has led to a number of new or enhanced influences for the sector arising.