One of my favorite parts of being a geobiology major is the abundance of field trips we get to go on. Quite a few classes in the Geological & Planetary Sciences (GPS) department have field trips, and we have a class dedicated to just field tripping around the American Southwest! So far, I’ve been on two field trip classes, with many more to come.
Ge 11b: Intro to Geobiology
My very first class in the geobiology major was our intro class, Ge 11b. I wasn’t totally set on the major yet, so I decided to take the intro class just to see, and I got hooked. We discussed the history of the Earth from the viewpoint of life, and it was fascinating! Our field trip for this class was to Death Valley in early spring (so it wasn’t super hot yet), where we observed fossils and sedimentary layers of the region.
The first day, we stopped by an abandoned talc mine, where we were able to clearly see different sedimentary layers, ranging from carbonates to sandstones. Our goal for the trip was to make a stratigraphic column, which essentially maps the layers of the Earth in a given region. The type of rock each layer is tells us a lot about the environment each one was deposited in.
After observing the talc mine, we went on a four-mile hike to start mapping our columns. Along the way, we saw lots of geographic features, such as stromatolites and ooids, both of which are sometimes made by microbes! Microbes are my favorite organisms, so I was quite happy to see these 🙂
On our way to camp, we also tried to stop by a date farm, which has amazing date shakes — or so I was told, since we unfortunately arrived just when they closed. We stayed at a basecamp in Tecopa, a city in the Death Valley region. We cooked a great meal of pasta, and everyone chipped in a little to help chop vegetables, cook the pasta, and clean the dishes. One of our professors, Joe Kirschvink, gave us wasabi Kit-Kats from Japan to try for dessert! The basecamp was surprisingly cozy, with bunks and a nice bathroom, so we were all rested for the next day ahead.
We stopped by several sites on the next day, where we saw pachyderm trace fossils, volcanic ash tuffs, and even got our own trilobite fossils to take home! We stopped by an outcrop of shale, where we spent a good half-hour splitting them open with rock hammers to try and find some trilobites. While I didn’t find a whole one, I got a few with good partial imprints!
Ge11a: Intro to Geology
Our geology field trip was also two days long. We traveled to 7 sites around the San Andreas Fault, observing different geological formations in the area.
Our first few stops observed the movement of the San Andreas fault, which has a distinctive bend in the southern part of California. We were able to observe this from the mountain ranges nearby, which followed the bend of the fault! We also stopped at several spots to compare different types of rocks, observing sedimentary layers and many metamorphic rocks, trying to obtain the relative age and relationships between them.
We spent the last part of the afternoon in Joshua Tree, where we did quite a lot of rock scrambling (while of course also analyzing the wash, or drainage path, of the granite rocks there). Try and find me in this picture! I’m wearing blue pants and a white cap. The acoustics of the valley were also really interesting — we could speak at normal volume and be heard a few hundred feet away!
We then spent the night at a campground in Joshua Tree. The park is known for being a great stargazing site, but we unfortunately camped there on a new moon and so were unable to see very many stars. Still, the night was gorgeous, and the moon was exceptionally bright.
The next day, we first stopped by a long-dormant volcano and spent a long while hunting for xenoliths, or mineral pockets in the volcanic rock. All of us found stunning green, orange, and black crystals embedded in basaltic rock. I was wearing cargo pants and filled about 3 pockets with these to bring back for friends!
We also took a long hike through Owl Canyon, which has an abundance of sedimentary structures — some of which were very recent, from the last rain cycle. Lots of mudstone, sandstone, and conglomerates of many types of granite were found along the canyon walls. We even noted past volcanic eruptions from volcanic ash layers!
On the other side of Owl Canyon was Rainbow Canyon, which had many similar features. We also saw evidence of lots of faulting and folding, as seen by the curved greenish rock here, which didn’t originally form with the main ridge (on the left side).
While I’ve only gone on two geology field trips so far, they’ve left a lasting impression on me. I now have a growing rock collection (to be blogged about later), but more importantly, I also have growing knowledge about the world around me and how it was formed. It’s a whole lot of fun being a GPS major!
