As gold makes it way to surface, what are the key observations for exploration geologists to make? How did we come to understand epithermal deposits and their relationships to intrusions and the paleosurface?  And how important are our structural observations?  

Gold can occur within Cu-Au porphyries and intrusion-related lodes, but also makes its way to the surface where a range of epithermal deposit-types host mineralization.   Following on from Episode 31 and the discussion of porphyry processes from bottom to top, today we are starting in the deeper parts of the system to explore K92's Kainantu Project in the eastern highlands of Papua New Guinea.  Chris Muller, VP Exploration K92 took time out to talk us through this big and varied project that includes an operating mine and new exploration discoveries.

 Richard Sillitoe and John Thompson are back to share their insights and extensive experience in a host of epithermal environments. Dick and John recap the history of our understanding of epithermal deposits and focus on the key relationships vital for exploration.  What is most important and what do we still not really understand?  This is a great conversation.

The structural controls on epithermal deposits are critical for exploration and development.  We are joined by David Rhys, Panterra Geoservices, to discuss commonalities and differences among the deposit types.  Dave was a co-editor with Julie Rowland of the SEG Reviews in Economic Geology Volume 21 Applied Structural Geology of Ore-Forming Systems (2020). He was also lead author on a paper in that volume entitled Structural Controls on Ore Localization in Epithermal Gold-Silver Deposits:  A Mineral Systems Approach.  

Theme music is Confluence by Eastwinds
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