By John Ayers
We left well before dawn in my Toyota Yaris and made the 382-mile journey this summer from Whittier to Tuolumne Meadows in Yosemite National Park. My 19-year-old brother, Matthew, rode shotgun and relaxed in the car en route. My younger brother accompanied me on this journey to be my field assistant and hiking companion — a safety precaution — and to help me carry out rock samples for later study in the lab.
The entire car ride was a mixed bag of emotions for me: immensely excited to backpack, camp and get the chance of a lifetime to do some awesome field work, yet feeling a little nervous and scared at the same time. One thing Vali Memeti, assistant professor of geological sciences and my research adviser, has often mentioned is that if you’re scared or worried, it’s because you care about what lies ahead, and you want to succeed or do well.
My objectives for the field trip were to map the selected research area and collect samples for geochemical analyses to be performed in the lab as research for my undergraduate thesis, “Investigating Causes of Compositional Variation in the Half Dome Grandiorite, Tuolumne Intrusive Complex, Yosemite National Park, CA: Big or Small Magma Chambers?”
In the field, the research consisted of mapping the eastern lobe of the half dome granodiorite unit found in Lyell Canyon in Tuolumne Meadows. Gaining an understanding of the growth and evolution of magma — molten rock found in deep reservoirs preserved in fossilized magma chambers known as plutons — provides knowledge of the magma plumbing of volcanic eruptions at the surface.
A better insight into how volcanic eruptions are connected to magma reservoirs and what processes cause these eruptions might improve the ability to predict future volcanic events. By researching the compositional variations in plutons, geologists can determine a sequence of events about how magma systems behave, like a detective trying to solve a mystery.
In Tuolumne Meadows,…