CHILCO blog

Project Background

This project is an exciting multi-disciplinary endeavor along the Pueyhue Cordon Caulle Volcanic Complex (PCCV) in the Andes Mountains. It is a NSF funded project through the University of Nevada Reno. The main project website is linked here.

The most recent eruption from this complex occurred in 2011, from Cordon Caulle, which produced a major ash cloud and viscous rhyolitic lava. During the 2011 eruption, a laccolith, an intrusive rock with a dome-shaped upper surface that is fed by a conduit from below, was emplaced around 200 m beneath the surface. The region of interest is shown below with the PCCV outlined with a red box.

The group joining us in Puyehue Cordon-Caulle is large with around 21 people from different institutions (University of Nevada Reno, University of Wyoming, University of Washington, Universidad de Chile, Universidad de Austral Chile, University of Hawaii Manoa, Sagenomin) with different scientific focuses. This is going to set us up to have interesting conversations and be able to learn more about this interesting region. 

Laccolith emplacement and study is the focus of this project and is currently being undertaken using different scientific methods (geophysics, geology, geochemistry, remote sensing, geomorphology etc). By better understanding the connections between the laccolith, hydrothermal and magmatic systems, and the general landscape we can begin to piece together a better understanding of the connections between these systems above and beneath the surface.

I am contributing towards constraining the laccolith and connections between the hydrothermal and geothermal systems. I am especially interested in understanding the melt fraction and composition of the laccolith and how it compares to erupted materials from previous episodes. There remain interesting questions about how the laccolith is influencing the hydrothermal and systems in the region and how it relates to the deeper magmatic system in this volcanic complex. 

These questions are well suited to magnetotellurics (MT), a method that is sensitive to electrically conductive materials such as fluids and magmas and that relies on the naturally occurring fluctuations in the Earth’s magnetic and electric fields. The plan is to collect around 10 sites total in a grid configuration. This will allow me to execute 3D inversions of the region, which can help constrain the bounds of any conductive bodies found. With the combination of the MT data, electrical resistivity tomography (ERT), and seismic data I am confident that I will be able to uncover something scientifically interesting.

This “blog” is being posted after I have safely made it back to Atlanta and is being written using entries from my personal journal and small notes I left myself in my phone.