Sunday, September 02, 2007

Becoming Thermochronic

This post is part of the maiden voyage of The Accretionary Wedge, a Geology Themed Blog Carnival. In this installment, geology bloggers describe why they study geology, or how they came to be geologists.

I had always been interested in science, and was pretty sure that's what I wanted to do coming out of high school. In high school, I had had excellent science teachers, especially in chemistry, biology, and an amazing course called "The Plants and Animals of California." These classes, and the beginning of regular outings with my mom and brother to go birdwatching, sparked my interest in the natural world.

Even though I went to high school in arguably the most geologically diverse and active states in the country, I had extremely limited exposure to geology. I entered college determined to be a biologist, I saw it as the best way to make a career out of understanding the natural world. One of requirements for the major (Environmental Biology), was Geology 105, Earth History. This course was taught by a Paleontologist, but we covered basic mineralogy, petrology, and structural geology in the labs. Within a few weeks I was hooked. I decided to sign up for the department's annual extended field trip, a two week adventure to some distant part of the country. That year we headed to the Colorado Plateau. The day after the college's graduation we packed up big twelve seater vans, piled in, popped in a mix tape, and headed west. This part of the country was entirely new to me, and I don't think in a blog I could ever do its uniqueness and beauty justice. On the trip, we spent time with some local professional geologists, seeing what they do for a living. We also spent perfect days hiking around looking at various geologic features, fossil sites, famous formations, and my favorite of the time, the enormous cross-beds of the Navajo Sandstone. I remember coming home from that trip. I got dropped off in Rock Springs Wyoming so I could take an Amtrak back to Sacramento. By the time the train was coasting down into the Great Valley of California I knew I was going to be a geologist.

What I ended up discovering was that geology is an incredible way to learn about the world surrounding you. That's actually what you study, everything around you. You take classes that utilize all other branches of science, you think about the history of life, the physics and chemistry of minerals at high temperatures and pressures, the time evolution of complex 3D structures, erosion, earthquakes, volcanoes, ripple marks, Hemichordata, Diatryma, polysynthetic twinning, oil, groundwater, nucleosynthesis.... At its core, geologists want to understand the world we live on, which means that all aspects of that world are open for inspection.

Geologists also study processes at such an enormous range of scales. From the billion year history of a craton to the almost instantaneous dynamics of earthquakes and fault slip; from the arrangement of atoms adsorbed to the surface of crystals to the structure of the entire planet. Because of the range of time and size scales we deal with we must think outside of human experience; something a million years old is young. There is something philosophical about that, professionally I am constantly bending my mind to scales of size and speed that I can physically never experience.

So why do I study geology? A brief list.

  1. Geology encompasses so much, it allows you to incorporate so many other skills and interests. We all know geologists who could pass as biologists, physicists, chemists, statisticians, engineers, or even hobos. For someone who is interested in all aspects of the natural world, geology is such a natural fit. Even as you specialize you still can incorporate such a wide range of information into your work.
  2. Geology involves a great deal of uncertainty. The experiments we are most interested in occurred millions (or billions) of years ago an an open system. Although we may use laboratories or very controlled and precise results from laboratories to understand geologic processes, there is a fundamental limit to the degree to which we can constrain geologic events. I enjoy this. I am constantly impressed with the degree with which we can untangle the past (see point #3), but the mystery of what we are undoubtedly missing is part of the excitement. How many deformational events can be recorded in a single thin section? I've seen up to 5 or 6 reported, but even that is a stretch. Geology is continually working to obscure itself.
  3. Geology is forensic. What I mean is that we work with scraps of events with infinitely complicated histories. I love the fact that people can work out complex series of deformational events simply by observing relationships in the field. I love P-T-ometry, and the fact that it works. Same with geochronology and thermochronology, we pick out these tiny minerals from a rock and can understand so much. Nutrient cycling and stable isotopes, short lived isotopes, basalt geochemistry, and 10Be. So little to work with but so much we've learned.
  4. The most important skill for a geologist is observation. On all scales, becoming a good geologist means learning to observe. This means that everywhere I go I try to pay attention to as many details of the natural world as I can. Some of the most significant discoveries in the history of geology weren't even made by classically trained geologists, but by people with exceptional skills of observation and reasoning (Alfred Wegener was a meteorologist.)
  5. Field trips and field work are some of the most enjoyable forms of work I can think of. I was drawn into geology through field trips, and have been able to do field work in the coast mountains of British Columbia, all over the US, in eastern China, and the Pyrenees. In addition to seeing these places, I've been able to experience them in ways most tourists, and even most hikers or backpackers, wouldn't.
  6. I've also been lucky to continually find excellent colleagues in geology. I've made great friends, and been surrounded by people I want to learn from. I don't know if other disciplines or fields are the same way, but for some reason I get along with other geologists very well. This may be different at other colleges, graduate programs, or universities, but for me, the geoscience community is a large part of my decision to become a geologist.
  7. Geology has more puns and funny sounding terms than almost any other science: love a geologist and feel the bedrock, tuff schist, have a gneiss day, perfect cleavage, apparent dip, subduction leads to orogeny, you know them all. They make me roll my eyes but I always chuckle.
  8. Geology is both beard- and flannel-friendly.
  9. Geology can be practical or esoteric or both.
  10. Seriously, who wouldn't want to be a thermochronologist?
  11. Every landscape is now interesting. I used to be bored with I-80 across Nevada, now I am always envisioning rotational normal faults and half-grabens. And don't even get me started on having the window seat on a clear day flying over the Sierra Nevada, canoing on kettle lakes, or staring at the "marble" or "granite" counter tops in the local coffee shop. If I am stuck at a boring party with no one interesting to talk to, I can entertain myself for hours with a stone fireplace.
  12. One of my committee members told me that the entire reason he became a geologist was that he liked being able to eat lunch in beautiful places. I tend to agree, it's hard not to be excited about field trips to spectacular landscapes. I remember in particular a scene from my 3rd or 4th year in grad school where a small field party was sitting around campfire as the sun was setting in the mountains east of Death Valley, drinking hot chocolate and whiskey and re-reading a Geological Society of America Bulletin article out loud.

In truth I feel lucky to have found geology, ended up in an excellent undergrad department, somehow got into and through a great graduate program, and now after 9 years of training and a post doc almost making as much as the average college graduate (almost is the operative word).

1 comment:

Kim said...

Geology has more puns and funny sounding terms than almost any other science

And geochronology/thermochronology is a particular rich source of puns. Especially for people like me, who have had more bad dates than good ones...