A Year in Review

Hi, it’s Casey and this is my first blog post in this wonderful group. I just graduated two days ago which is pretty crazy. This year working in the Geomorphology lab has been great. I really enjoyed the variety of tasks that I have done. Prior to this year, I went on a whirlwind of a China trip for research—I got stuck in Beijing for 48 hours on my way to Jiuzhaigou, then flew first class to Chengdu, had a great time in Jiuzhaigou National Park surveying and collecting charcoal samples, and then travelled on my own in Chengdu for a bit and got to see some Pandas at the breeding center. Here is a picture of some terraces in Jiuzhaigou that I have been researching all semester.

I spent last semester working in GIS and mapping the locations of the samples and figuring out what data we had, and what questions about Jiuzhaigou we could solve. Unfortunately, all of the GPS points we took in the field this summer were wrong and didn’t match up with the map so we couldn’t use any of them—but that’s field work for you! Here is a picture of a figure I made last semester with some of the sample points we have.

Originally, Amanda and I were trying to figure out if the terraces are anthropogenic in origin or caused by natural geological processes, but that proved to be too big of a problem to figure out with the data we have. Instead, we have tried to figure out where the loess in Jiuzhaigou came from—the Chinese Loess Plateau, the Chengdu Basin, or the Tibetan Loess Plateau.

The data we have available are OSL, grain size, color, and radiocarbon data. The color data we have are very similar to other areas and didn’t tell us much. The OSL data told us that we have early Holocene ages (ranging approximately 9.53-1.20) thousand years ago. What became really key was the grain size data.  

The past few weeks, I was working with grain size data to create figures modeled after the grain size distribution curves and depth profiles from the 2010 paper “Timing and provenance of loess in the Sichuan Basin, southwestern China” by Yang & Fang et al..

Here’s an example of what most of the grain size data looks like all on one graph:

It has been really exciting because it seems pretty certain that the loess in Jiuzhaigou is coarser than the loess in the Chinese Loess Plateau and in the Chengdu basin which means it must have come from the Tibetan Plateau.

Even though the semester (and my time at Oberlin) has ended, there is still more work to be done on this project. This includes sieving a sample that had a double peaked grain size distribution curve and writing a paper on loess provenance in Jiuzhaigou, China. 

Signing off for the first and last time,Casey