How it works
A magnetometer records the magnetic field along lines or at stations. Processing accounts for changes in the background field and survey conditions. Geoscientists examine patterns and test possible source geometries. A magnetic high may indicate a particular rock unit, but its cause must be established from geological evidence.
Where it is commonly used
Magnetics is widely used for geological mapping, mineral-system interpretation, tracing dykes and contacts, and studying the basement beneath sedimentary cover. It is useful across the Canadian Shield and in basin settings where the underlying magnetic rocks help define the structural framework.
Why use this approach?
Public and commercial magnetic surveys can provide broad coverage early in a project. Their patterns help connect isolated outcrops or wells into a regional interpretation. Ground follow-up can investigate selected features at closer spacing when the target warrants it.
What it cannot tell you on its own
A magnetic anomaly is not proof of economic mineralization. Some deposits have little magnetic contrast. Remanent magnetization, depth and overlapping sources can complicate interpretation, while vehicles, fences and other metal can affect ground readings.
From data to interpretation
We check survey dates, line spacing, coordinate systems, processing history and data rights before combining datasets. New ground work, where included in the scope, uses suitable reference monitoring and repeat checks. Interpretation compares mapped trends with geology, gravity and electrical information.
What you receive
Magnetic maps and profiles; interpreted contacts and structural trends; modelling where appropriate; target rationale and competing explanations; a practical follow-up plan.
How it compares & fits with other methods
Gravity adds density information and MT adds electrical information. Their agreement can strengthen a geological interpretation, but they need not respond to the same feature. Existing airborne magnetic coverage is a useful dataset; it is distinct from Dwell providing airborne acquisition.
An example decision
A BC mineral explorer has a promising outcrop and an older regional magnetic survey. We assess whether the survey can trace the host unit beneath cover, then identify which parts of that interpretation merit field mapping or a closer ground survey.
Examples describe possible assignments, not completed Dwell projects. Equipment, acquisition partners, coverage and deliverables are agreed in the proposal.
Technical background ↗