More specifically, Dox looked at volcanic rock samples from Sand Mountain under a microscope in an attempt to “figure out their chemical makeup and how they relate to each other,” she said. The minerals she focused on were skeletal and zoned olivine, plagioclase, and spinel. Skeletal and zoned refer to the rates at which the minerals were created: “When it’s skeletal, that means that [the mineral] was not fully formed at the time of eruption; when it’s zoned, that means that it cooled at different rates,” she said.
Her work also involved tracing samples to a given magma chamber, using indicators within the minerals to identify their source within the volcano. Dox highlighted the different volcanic structures she studied, explaining that magma chambers are where molten lava is held before it erupts. Scientists believe there to be three or four of these chambers at Sand Mountain, but they cannot simply go down and count them. Dox said that it is only through “analyzing the erupted lava and the phenocrysts in them that we can see what it was like down there, and try and piece together which chamber different flows came from.”
The research process was broken down into different steps, Dox explained. First, she combed through samples under a microscope, seeking to identify ones with the most potential to be interesting. From there, she examined samples under a scanning electron microscope to get a more in-depth picture of the rocks. And in the final few weeks, Dox plotted her data on graphs and histograms to better analyze her findings and figure out what they meant.
Bria Dox ’22
Hometown: Boxford, Mass.
High School: Masconomet Regional High School
All of Dox’s research was done at Hamilton, using samples brought to campus from Oregon. This project in particular, she said, was started years ago by Senior Laboratory Technician Rick Conrey, who has been recruiting student researchers to help with the work in the summer. The mineral chemistry stage of the project, with which Dox was involved over the past few weeks, had not yet been completed with regard to these particular volcanic samples before this summer.
Dox’s advisor, Winslow Chair and Geosciences Professor Dave Bailey, recommended this project to her after hearing about her academic interests. “I said my favorite class that I’ve ever taken is mineralogy,” she recalled. “And I had just come out of [Bailey’s] volcanology course … together, that set the stage for this to be a good project for me.” Although she has completed this summer’s research, Dox is looking forward to expanding on this work during the upcoming school year through her senior thesis.