Project Description
The San Rafael Volcanic Field (SRVF) was active between 6.5 and 3.5 million years ago. Since then, volcanic products traditionally found on Earth’s surface have eroded away, exposing the volcanic plumbing beneath. This includes many dikes – sheet-like bodies that connect a magma chamber at depth with the surface eruption. Currently active volcanic systems like SRVF pose hazards for surrounding communities, and broader project goals are to understand the timing and duration of magma injection events to inform hazard models. A secondary goal is to better understand dynamics of the injection events. For example, are dikes injected vertically or laterally? One relatively rapid way to assess magma flow direction is to measure the orientation of the magnetic minerals in the rock by applying a magnetic field and measuring the response. Magnetic susceptibility is the magnetization induced in a rock in response to an applied field. In most cases, susceptibility will be greater if measured parallel to the alignment direction, and lower when measured perpendicular to the alignment direction. This measured anisotropy of magnetic susceptibility (AMS) can therefore be interpreted in terms of mineral alignment and magma flow that might have produced that alignment.
Tasks and Responsibilites
Samples from a series of dikes in the SRVF were collected in October 2025. Most of the samples have already been prepared for analysis, but the student may need to make adjustments to the physical size of some samples by using a rock saw to trim them down. They will then be responsible for 1) measuring AMS on dike samples from one to two study areas; 2) plotting the results and assessing their statistical significance; 3) comparing the results to the orientation of the dikes as measured in the field; and 4) making interpretations. They will also be responsible for documenting their work and organizing the data so it can be shared with the broader research team.