The 4-D architecture of a porphyry Cu mineralising magmatic-hydrothermal system
Course Details
The archetypal Yerington District, western Nevada, hosts porphyry Cu(-Mo-Au) deposits, several Cu skarns and numerous Fe oxide-Cu(-Au) lodes within a middle Jurassic batholith and its overlying volcanic terrane. Late Cenozoic basin and range extensional faulting and associated fault block rotation has exposed a unique <1 to ~8 km palaeodepth cross-section through the district. This allows the 4-D architecture of the porphyry mineralising magmatic-hydrothermal system to be studied in detail.
Traversing the Yerington Batholith, this field course details the system’s magmatic-hydrothermal evolution. This includes exploring: the magmatic-hydrothermal transition; porphyry Cu(-Mo-Au) mineralisation and associated hydrothermal alteration; related skarns; deep Na-Ca alteration; the advanced argillic environment in the overlying volcanic terrane and associated Fe oxide-Cu(-Au) mineralisation. Drill core reviews will supplement observations from the field, and daily seminars will reinforce learning.
From their own first-order field observations in the world’s best-exposed section through a porphyry system, participants will have the opportunity to:
- Gain an understanding of the 4-D architecture of a magmatic-hydrothermal porphyry system, including the relationships with skarns and the volcanic environment.
- Become familiar with porphyry-style mineralisation, specifically the characteristic vein types and typical zonation within porphyry copper deposits.
- Recognize and identify the typical hydrothermal alteration assemblages of porphyry systems, and their 4-D zonation.
- Broaden applied field and exploration techniques through specific field mapping and core logging exercises, including gaining a basic understanding of the ‘Anaconda method’.
- Develop expertise in the characterisation of porphyry systems, their genesis, and awareness of exploration toolkits.
Who Should Attend
• Geologists • Mining Engineers • Managers• Geochemists • Geotechs
This course is designed for industry professionals who primarily focus on, or would like to develop their understanding of, magmatic-hydrothermal systems. Graduate students and academics are also welcome to join at a discounted rate.
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Course Outline
Day 1
- You will be arriving the day before the course starts in Yerington, Nevada, USA. The next morning we will begin with a safety briefing and an overview of the classic Yerington District before driving to the field area.
- We will then start our transect up through the porphyry system, starting with the ‘root-zones’ and moving up into the exposed cupolas of the Luhr Hill granite.
- Discussions will focus on the sources of mineralising fluids.
Day 2
- We will continue our transect up and across the magmatic-hydrothermal system.
- We will investigate the magmatic-hydrothermal transition, multiple porphyry deposits, and zonation of hydrothermal mineralisation and alteration.
- Mapping exercises will briefly introduce a modified ‘Anaconda method’
Day 3
- We will move up into the system’s overlying volcanic environment to examine alteration in the upper 1 km of the system.
- En route, we will utilise the several opportunities to assess different styles of mineralisation and prospects within the District.
Day 4
- We will spend most of the day viewing drill core from recent drilling campaigns. From the drill core, we will assess the range of vein types typically associated with porphyry-style mineralisation, as well as characteristic hydrothermal alteration assemblages.
- Core logging exercises will briefly introduce a modified ‘Anaconda method’.
Day 5
- We will move laterally in the system to investigate the relationship with skarn-style mineralisation.
- Our discussions will move onto exploration targeting, as well as both the benefits and issues associated with exploring a mature district such as Yerington.
The arrival airport for this field trip is in Reno, Nevada. The field trip is offered every year in the first week of November and costs $3500/person*. This cost is all-inclusive and includes 5 nights hotel stay, all meals, snacks and drinks, field vehicles, fuel, permits, guidebook, exercise materials, and tuition.
*A 5% service fee is added to credit card payments. This fee can be avoided by sending a wire transfer or check.
