Welcome to the blog for the Oberlin College Geomorphology Research Group. We are a diverse team of students working with Amanda Henck Schmidt on geomorphology questions. This blog is an archive of our thoughts about our research, field work travel notes, and student research projects. Amanda's home page is here.

Sunday, October 23, 2016

Geology Can Be Confusing Sometimes: A Memoir

Hey Everyone,

I'm Gabe, a 4th year (ish), and I just started working in the lab this semester. And it sure has been a heck of a time. I'll start by saying that I came into geology relatively late. Since coming to Oberlin as a transfer last year, I've been taking as many geo classes as possible, and finally worked up the courage to declare last semester. It's been an eventful and exciting year, and I've learned so much over the past three semesters.

With that said, though, I'd be lying if I said I didn't find myself scratching my head sometimes, especially when it comes to research this semester. I took Earth Surface Processes last semester, and while I remember learning about isotopes and geochemistry... things have a way of slipping away during summer vacation. At the beginning of this semester, I figured that since I'm now a member of a team that's largely dedicated to working with these concepts, it's probably a good idea for me to understand them. During one of our first lab meetings this year, Amanda drew a few pictures and explained to me how the different fallout radionuclides (most importantly: 7 Be 210Pb and 137Cs) reach the soil, how they are differentially adsorbed and stored, and how they are useful to geologists for understanding erosion. On a broad level, I understood the purpose of the research and the driving observations but... there were still a lot of questions, many of which I couldn't even figure out how to put into words.

Over fall break, Amanda gave me three papers which are all directly relevant to the research we do in the lab. Reading science writing, an art in itself, is still something I'm getting used to, but I made my way through all three papers unscathed. What I found really cool about these three papers was how differently they used the same relatively specific tools to investigate fairly different things. One paper, from 1992, was largely theoretical. The paper investigates how radionuclides, or "radiometric fingerprints," can be used to gather information on suspended sediment sources (another topic I should maybe read up on) because they are independent of many otherwise limiting factors like lithology and soil type. Another paper focused on how radionuclides can be used to distinguish different types of erosion, specifically different types of sub-surface erosion. This paper had a slightly more practical approach, and talked about how this distinction between erosion types can help guide erosion mitigation attempts. The third paper did not discuss radionuclides, but instead focused on the calculation of sediment yields in order to understand anthropogenic effects. This paper also had some fun historical context which even attracted my parents into talking about geochemistry with me. 

Reading these three papers, especially combined with the experience of leaching and running samples, was incredibly helpful. Although I still don't understand a lot of the the nitty gritty geochemistry, and may have skipped or skimmed a few paragraphs here or there, I definitely feel a lot more confident with my role in the research group as we enter the second half of the semester. And I'm certain that my understanding will only become more refined as the semester continues.

Tuesday, October 11, 2016

Let the leaching begin!

Hey everybody!

I hope you all are having a wonderful semester and enjoying the refreshing autumn weather. October break will soon be upon us!
I’ve had a very exciting first few weeks back at Oberlin. A large portion of the semester consisted of prepping for GSA back in September. That involved finalizing the leaching data that Adrian and I collected last semester and any new data collected over the summer by Marcus and Monica. Monica, Marcus, Adrian and I also spent time putting together a poster worthy of a presentation at GSA. And before I knew it, I was on a plane to Denver, Colorado to present at the conference!
It was a fantastic experience overall. I had the opportunity to see Oberlin alums, meet professionals from all different fields of geology, and even explore the city of Denver a bit with my fellow geo-nerds. The presentation of the poster with Adrian and Monica went smoothly and we spent the rest of our time at GSA going to geology talks and meetings. It was a very informative trip and even gave me a few new ideas about which fields of geology I may wish to pursue in the future.
And now on to…LEACHING! Our lab group has split up into smaller teams and everybody is embarking on the wonderful adventure that is leaching in the Carnegie geochem lab. Each lab member is getting to learn how to do the entire process and many samples are being leached every week. Monica, Gabe, and I are working on the CH-0XX samples (samples from the China trip a year or two ago).
As of right now, that is all that’s been happening. I’ll upload another blog post later in the year and hopefully have more to say. Monica and Gabe are both on my mini-team for the leaching project, so feel free to check out any blog posts that they upload and keep up-to-date on our progress!
Hope you all are enjoying the amazing ~fall~ weather!


P.S. Check out Marcus’ post if you want a quick refresher on the leaching process! J

Thursday, October 6, 2016

Mid Semester Update

Hello everyone,

The colors haven't started changing outside just yet, but inside Oberlin's geochemistry lab there's certainly a lot going on. This semester has been focused on leaching!A former student in the lab came up with a plan to obtain data without having to use all sorts of proxy methods and avoid getting unrealistic values. To do this we remove grain coatings from samples, increasing the accuracy of our measurements. This involves using a fair amount of HCl to completely soak the sample; after some trial runs we've concluded that a 4:1 ratio of acid to sample is the sweet spot. Our process involves soaking the sample for at least 24 hours in acid in nalgene containers which are mostly submerged in a sonic bath. This procedure is perfect for Halloween as the contents of the bottles turn a spooky orange-ish brown when they are done. After that we have to decant off the leached grain coatings from the rest of the sample, a meticulous process involving the centrifuge, De-Ionized water and lots of patience. This part is the most time-consuming overall, but once the two components are separated out its smooth sailing. Throw the container holding acid on a hot plate and let all the HCl sizzle off and put the other container holding the residue in the oven. When thats all over we should have to containers of one sample that are ready to be run through our gamma spectrometer. This is the process i've been working through alongside most of the others working in Amandas lab this semester and its been a good time so far. This half of field work isn't as glamorous as spending nearly three weeks in China but its still rewarding nonetheless. We've  faced a few hurdles this semester already but overall its looking to be very data rich end of 2016.

Once the semester is over we should have a computer full of meaningful data points which will make for a much more interesting post, full of analysis and maybe even some pretty graphs

But until then this is all I've got to offer,