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Undercover and Deep Geology from QUEST Electromagnetic and Gravity Data

Lead Researcher(s):  Dianne Mitchinson

Project ID:  2022-002

Key Research Organization(s):  University of British Columbia - MDRU

Project Location:  North Central BC

Strategic Focus Area:  Minerals

Summary



A belt of rocks known as the Quesnel terrane extends roughly northwest-southeast through BC’s interior and is host to many known mines including Mount Milligan (Cu-Au), Mount Polley (Cu-Au) and the Gibraltar (Cu-Mo). However, in the Prince George area, the Quesnel terrane is obscured by a thick layer of glacial sediments. Without a better understanding of the geology under the thick layer of glacial till, mineral exploration and other land use decisions are hindered.

This project will use Geoscience BC’s QUEST project regional electromagnetic and gravity data to derive new information about bedrock geology in the central Quesnel terrane. These particular datasets have been underused in interpreting bedrock under glacial till in central BC (when compared to magnetic data) but show interesting correlations with known geology and structures. Specifically, electromagnetic and gravity data show promise in distinguishing between different volcanic units and can identify igneous intrusive bodies as well as structures. Interpreting this data should provide enhanced information about the geology under glacial till in the central Quesnel terrane and may help identify geological settings favorable for mineral deposits.

The Need

Due to extensive glacial till overlying bedrock in BC’s central Quesnel terrane, the ability to map and sample the bedrock at surface is greatly limited. As the region has high porphyry copper-gold mineralization potential, research that enhances understanding of the bedrock geology can aid in the identification of specific locations to target for further research and exploration.

Goals

This project fits under Geoscience BC’s Strategic Objective of ‘Identifying New Natural Resource Opportunities’ and our goal to:

  • Undertake research that adds value to existing or ongoing data sets through ground-truthing studies, data interpretation and mining camp compilations

Specifically, this project aims to:

  • Develop a revised map of the bedrock geology for the QUEST area from integrated interpretation of available geophysical data and other datasets that were not available when the bedrock geology map was last updated;
  • Add geologic details, such as internal variability in volcanic domains, buried intrusive bodies, or new contact or structural interpretations, to the existing but largely inferred geological map of the central Quesnel terrane; and
  • Determine whether VTEM and gravity data and models may be a useful tool elsewhere in BC for identifying buried geology and possible mineral deposit environments

Benefits

Gravity and electromagnetic surveys show promise for distinguishing between certain volcanic units and can support the identification of intrusive rocks and structures. As Geoscience BC’s 2007 QUEST project captured this geophysical data over the central Quesnel terrane, this project aims to utilize this existing data and subsequent interpretations to explore and define the ability for electromagnetic and gravity data to distinguish lithologies under cover, and to corroborate features interpreted previously from magnetic data.

Models of interpretations of newly distinguished or interpreted geological and structural features will be produced for use by geologists and explorers looking to identify potential areas of interest for new copper-gold mineral exploration.

Location

The study area is comprised of the QUEST survey area in BC’s North Central region between Williams Lake and Mackenzie.

Deliverables