Field Trip: Active and Extinct Epithermal Environments of the North Island New Zealand

FIELD TRIP: OCT 1-7, 2025

(immediately after the Society of Economic Geologists Brisbane Conference)

TRIP OVERVIEW AND PURPOSE

Epithermal gold-silver deposits are intimately associated with complex volcanic, structural and tectonic environments which were incredibly dynamic. The North Island of New Zealand is renowned for its volcanic landscape, hot springs and gold-silver deposits.

This 7-day excursion through the Taupo Volcanic Zone and southern Coromandel peninsula provides an overview of epithermal deposits and the processes that lead to their formation. The itinerary includes visits to recently active volcanoes (Tarawera, Taupo and Tongariro), active geothermal systems (Waiotapu, Orakeikorako, Waimangu, Wairakei, Rotorua) and epithermal gold-silver deposits in the Coromandel peninsula.

Participants will learn about mineralizing environments from “bottom to top”, review drill core from high-grade Au-Ag mineralization, see the expression of epithermal environments at different depths, “see” active gold deposition in Champagne Pool, and learn about volcanic-geothermal-mineralizing environments in some of the worlds youngest rocks.

TRIP LEADERS

The trip is led by Stuart Simmons (Hot Solutions Ltd.) and Shaun Barker (MDRU).

Stuart Simmons is a consulting geoscientist and a research professor who has been working on epithermal deposits, geothermal resources, and hydrothermal processes for over 40 years. Much of this effort has been directed at understanding ore-forming processes based on investigations in the geothermal systems of the Taupo Volcanic Zone and large precious metal deposits around the circum-Pacific. His published work has appeared in Economic Geology, Geochemistry-Geophysics-Geosystems, Geology, Geothermics, Mineralium Deposita, Nature, and Science. Since 2013, Stuart is based part of the year at the Energy and Geoscience Institute, University of Utah in Salt Lake City, where he investigates geothermal resources in the western USA. He received his PhD in Economic Geology from the University of Minnesota (1987), and he has held academic appointments at the University of Auckland (1987-2008) and Colorado School of Mines (2011-2012). He was awarded the SEG Silver Medal in 2014 and SEG Marsden award in 2018. From 2022-2024 he was the President of the Society of Economic Geologists.

Shaun Barker is Director of the Mineral Deposit Research Unit, who undertook research on alteration footprints and vectoring tools in epithermal systems at Waihi from 2012-2018, and led student and industry field trips to Waihi and the Taupo Volcanic Zone. Shaun has active research projects in the volcanic-hosted epithermal, VMS and porphyry deposits in the “Golden Triangle” of northern British Columbia.

This field trip will likely be one of the last ones that Stuart leads in New Zealand – so don’t miss your chance to join us!

All transport by Minivans, departing from and returning to Auckland airport.

ITINERARY

Day 1. Depart Auckland (from airport motel), visit historic epithermal mining areas

• Visit Basement rocks
• Visit historic Karangahake Gorge and historic epithermal mining areas
• Overnight Waihi

Day 2. Waihi gold mine visit with Oceanagold

• Visit Waihi Gold Mine including drill core review. Review variation in structural controls, mineralization vein textures and paleodepth. Talk on discovery history in Coromandel Peninsula and Waihi.
• Depart Waihi mid-afternoon for Rotorua
• Overnight Rotorua

Day 3. Active geothermal and mineralization environments

• Visit Waiotapu Wonderland to see surface expressions of active geothermal environments, hydrothermal eruption products
• Visit Orakei Korako geothermal area to understand dynamics of structurally-controlled hydrothermal fluid flow in an active environment
• Overnight Rotorua

Day 4. Volcanic-hydrothermal Interactions

• Visit Waimangu Volcanic Valley where we will see features relating active volcanism to hydrothermal fluid flow
• Visit Ohakuri epithermal prospect
• Overnight Rotorua

Day 5. Dynamics of bimodal Volcanism.

• Visit to Tarawera Crater on guided walk to visit one of New Zealands largest, recent volcanic eruptions
• Redwood forest walk to overview of Rotorua geothermal field
• Overnight Rotorua

Day 6. Tongariro National Park: 50 km.

• Visit “Craters of the Moon”
• Overview Lake Taupo, one of the world’s largest volcanos
• Overnight at National Park

Day 7. Active Stratovolcanism and hydrothermal fluid flow

• Architecture of stratovolcanos
• Silica springs
• Return to Auckland Airport

COST

The estimated cost for the trip is ~CAD$6,000 which will be finalised at the time spots are offered.

Please sign up to be contacted when registrations open.

PLEASE NOTE: Due to anticipated high demand we are seeking to ensure that all MDRU members have equal opportunity to access our field training and are doing this through an EOI process from which applicants will be offered an opportunity to confirm their registration. Please submit your EOI by March 15. Participation will be subject to availability and further selection criteria. Once registrations open, you will receive an email with a link to the application form which will include payment to confirm your spot.

PAYMENT AND REFUND NOTES
To ensure registration for any short course, it is mandatory to make the full payment in advance. Please note that if our decision to conduct a course relies on reaching a minimum class size, refunds cannot be granted. Refunds will only be considered up to 3 weeks before the course commences, subject to a 15% administrative fee. Full refunds will be provided only if the minimum enrolment requirement is not met and the course is canceled.