Classifying, distinguishing and exploring for intrusion-related gold systems / Классификация, распознавание и исследование золоторудных систем, связанных с интрузиями

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. 
Ambiguous, poorly understood or poorly-defined deposit model classifications are an economic geologist’s greatest weakness as they result in ineffective exploration strategies. Deposit classifications can be better differentiated from others by using a set of distinguishing features and not characteristics that may be common to many hydrothermal deposit types. Herein, the historical evolution of intrusion-related gold deposit concepts is briefly presented, followed by a statement of the current state of intrusion-related gold models, and concluded with a set of characteristics by which IRGS can be distinguished from other gold deposit types in similar geological settings.  <...>