Joshua Murray, 2018, Geosciences

Joshua Murray ’18

The Columbia River Basalt Group is a collection of lava flows in the Pacific Northwest that formed mostly between 17 and 14 million years ago. The basalt flows themselves can be over a kilometer thick: smaller than the Deccan and Siberian Traps, which are often thought of as causes of mass-extinction events, but still significant enough to have influenced climate. By collecting samples of sediment that accumulate during hiatuses of volcanic activity throughout the stratigraphy in Washington, Oregon and Idaho, then separating the mineral zircon from these sediments, our group hopes to date this volcanic event using uranium-lead geochronology on a high-precision mass spectrometer. These dates are vital in calibrating this volcanic activity with any climactic variation at the time, hopefully providing insight into the effects of eruption rates and CO2 output on the climate. My roles in this project included lab assistant, trip planner, and field geologist, with hands-on duties including finding sample sites, grinding the samples into sand, identifying rocks and minerals, and more. This internship helped cement my decision to major in Geosciences, and my junior paper will likely focus on geochronology.