Project Update

April 2022

The 2021 Field Mapping Report was released, outlining the surveys, data collection and results of the field season in the Mount Cayley area. This report gives new data for bedrock ages, gravity and magnetotelluric surveys, and ground temperature.

August 2021

Geoscience BC hosted an online community open house meeting on August 4, 2021, featuring project lead Dr. Steve Grasby of the Geological Survey of Canada, and Geoscience BC’s Carlos Salas that provided an update on the work and findings from Phase 1 of the Garibaldi Geothermal Volcanic Belt Assessment Project.

The Need

Canada is the only country on the Pacific Rim not to produce energy from geothermal. For geothermal energy resources to play a significant role in the future Canadian economy, reliable, baseline geoscience information about the depth, temperature and permeability of potential aquifers – and their suitability to generate geothermal heat and power – is necessary.

Phase 1 of this project used a Geoscience BC compilation of previous public and private research at Mount Meager (a single volcano in the Garibaldi Volcanic Belt) to guide new research into the geothermal resource potential of Canada’s preeminent hot spot. The results of this project can be used in the development of new geologic, hydrogeologic and structural models for the region, creating greater certainty for geothermal energy exploration.

Project Goals

This Energy project fits under Geoscience BC’s Strategic Objective of Enabling Clean Energy and our goal to:

• Continue geothermal resource mapping and research focusing on economically viable projects and sites with high geothermal energy potential.

Specifically, the project’s goals are:

• Phase 1: To reduce exploration risk by increasing our knowledge of the controls on rock permeability in the geothermal reservoir underneath Mount Meager through the application of a range of geoscience tools, including field mapping, remote sensing and magnetotelluric and gravity surveying and passive seismic geophysics. These results can be used to support structural geology, hydrogeology, volcanology and geochemistry studies of the area.
• Phase 2: This phase is applying the science and methodologies developed in Phase 1 to the Mount Cayley area. Additional field work will be conducted in the summer of 2022, however, the 2021 field mapping update summarizes work completed to date and provides all data collected from the summer 2021 field season. The Phase 2 Final Report will include research results and data from the Mount Cayley area and will include a summary of geothermal potential of the Garibaldi Volcanic Belt utilizing findings from both research phases.

Project Benefits

Geothermal energy has numerous advantages compared to other renewable energy sources, namely in its low environmental footprint and ability to provide a stable baseload-power supply without the need for energy storage solutions. The baseline geoscience information generated by this project will help geothermal energy producers, communities, governments, and Indigenous groups have a better understanding of the potential geothermal resource throughout the Garibaldi Volcanic Belt.

Potentially, this geothermal resource could supply baseload power to the Lower Mainland in combination with other renewable energy sources. There is potential for additional capacity to be used to generate green hydrogen.

Survey Area

The Garibaldi Volcanic Belt is a chain of young (less than 11,000 years old) volcanoes in southwestern BC. It extends north and northwest from Squamish, BC, for approximately 200 kilometres. The region is also known to have abundant thermal springs.

Mount Meager is an ice-clad volcano situated 160 kilometres north of Vancouver in the centre of the Garibaldi Volcanic Belt. The understanding gained in the smaller Mount Meager area can be applied across the wider Garibaldi Volcanic Belt.

Mount Cayley is approximately 25 kilometres west of Whistler.

What was Found?

Geoscience BC encourages anyone considering geothermal development to first engage with First Nations in the area.

In April 2020, an extensive seven-chapter report on fieldwork conducted in 2019 was published.

In July 2021, a comprehensive report summarized the field program and data collected in Phase 1 of the project. It included:

• Detailed bedrock mapping to enhance understanding of the spatial distribution of volcanic rocks that form the Mount Meager Volcanic Complex, with a particular focus on rock types with preferential reservoir properties. Field mapping included recording rock-property observations at 962 field stations and production of four new geological maps.
• Fieldwork to collect over 1,200 structural geology measurements was conducted to measure spatial distribution and variability in fracture orientation and fracture density.
• Gravity measurements were taken at 122 stations around the Mount Meager Volcanic Complex with the aim of mapping its internal structure.
• Collection of magnetotelluric (MT) data was aimed at greatly expanding coverage beyond that collected in the 1980s using modern and more field-portable instruments. The goal was to use the new MT data to determine permeability variations in the subsurface and link these to flow rates observed at the surface.
• Fifty-nine passive-seismic sites were established for characterizing crustal structures associated with the area of high geothermal heat and how those vary within the geothermal system. The observations from this array will be used to identify the distribution of low seismic-wave speeds, which can mark the distribution of fractures that serve as pathways for geothermal fluids, as well as magma chambers.
• The major geologic structures controlling the geothermal fluid pathway were also documented through structural field geology mapping of faults, folds, and fractures of basement and young volcanic units, together with paleomagnetic measurements and geochronological dating to reconstruct the potential pre-deformed stage of structural geology features and define sequence of deformation events.
• Hydrothermal alteration characteristics of the geothermal systems at Mount Meager were examined providing physical, mineralogical, and chemical characterization of hydrothermally altered volcanic rocks.
• A detailed study was also conducted to understand the distribution, volume, eruptive duration, and age of the Cheakamus basalts, a group of Quaternary basaltic lavas and some of the youngest volcanic rocks within the Garibaldi Volcanic Belt.

In April 2022, a report on the 2021 field season in the Mount Cayley area was published. This work focused on: bedrock mapping and age dating of the volcanic eruption history; a gravity survey; establishing an array of magnetotelluric stations focused on the deeper volcanic plumbing; and ground temperature and fracture studies.

The volcanic history of the Garibaldi Volcanic Belt can provide some insight into areas with higher temperatures related to shallower magma chambers. Such knowledge can also aid in assessment of the volcanic hazards associated with any future development. Given this, work was conducted to refine the eruptive history of the core Garibaldi Belt area.