Plate Tectonics and Mineralisation: An Overview of Metallogenic Epochs and Provinces in India
a number of regional examples of these exploration methods are given, and specific in-depth discussions are provided for sillitoe s discovery of the eterna and the chimney copper-gold porphyries (sillitoe et al 2012, 2016 ). the focus in the latter article is on the use of metallogenic criteria to delineate the pumiceous, biotite-bearing mafic and ultramafic units of the amd in the willamette valley, oregon, united states (us). the discovery history of the willamette valley deposit is also given in that article, and the discovery of the orca copper-gold porphyry in the okanagan valley of southern british columbia is also mentioned. this discovery followed the 3d modelling of the largely unrecognized porphyry expression of the coalmont gold district in the tahoe range, nevada, us. the coalmont deposit is mentioned because of the exceptional geochemical and mineralogical heterogeneity and the unusual metallogeny. finally, the importance of metallogenic criteria to the discovery of the vancouver island subduction-related gold-copper-molybdenum (gcom) deposit in northwest british columbia, canada, is discussed (chiarabba et al 2019 ).
metallogenic epochs and provinces of india pdf download
two very interesting papers on the application of metallogenic models to the discovery of active hydrothermal vents in the southern indian ocean are referred to in this review. the first, by rasch et al. ( 2018 ), is one of the most important in recent years because of its ability to give a clear definition to the site-specific metallogenic model of a hydrothermal vent field in the kerguelen plateau, sub-antarctic. the vent field is described in the context of the discovery of a new deep gold-copper-zinc (gcoz) mineralization. the article is valuable because it shows that metallogeny can be an important discovery tool in its own right and not just as a presuptive tool for the discovery of a target that was already there in the surface or subsurface environment. the second paper, by sillitoe ( 2019 ), describes the discovery of a new hydrothermal vent field in the eastern indian ocean. the field is located in an active arc-trench volcano known as the chandrayaan i ridge, where a previously unknown hydrothermal vent field is situated. the field is described in the context of a surprising discovery of a new deep, ultramafic, hydrothermal gold-copper (au-cu) mineralization.