Winter Term Recap

Hi, This is Ely,

I wrote on the blog earlier this fall, talking about the beginning of my journey as a research assistant in the geomorph lab. I’ve been working with Marcus on his Dominica KECK research project. Over the summer, Marcus was able to travel to Dominica in order to collect river sediment samples. Since the start of fall, I’ve been helping Marcus with running these samples in HARBIN and the XRD.

After Hurricane Maria hit the Caribbean, Amanda noticed that we had the rare opportunity to collect post-hurricane sediment samples from the same locations that they were collected in the summer, before the hurricane. We set a date to head back to the island during winter-term.

Before leaving for Dominica, I spent time looking into software that would better allow us to identify the composition of our samples from the data the XRD provided. Up until now, we’ve been trying to do this using d-spacing charts and sifting through extensive lists of elements and minerals hoping for a match. However, the software we are using should supposedly do this for us in a matter of seconds. The programs we are using are Match! 3 and MAUD. Match! 3 is what we use to identify likely minerals within our samples. It looks through an index of thousands of known minerals and their XRD data sets, trying to fit each one to ours. One issue is that our samples are mixtures of many different minerals, and Match! 3 tries to fit a single mineral to our entire XRD data set. We can combat this by taking many minerals off of Match! 3’s candidate list, as well as data for minerals that make sense with the geological history of Dominica. We throw all of these into MAUD, which makes a custom diffractogram using Rietfveld refinement. It’s really a process of trial and error, adding in likely minerals, and removing them if MAUD can fit them onto our sample data.

Using Match! 3 to analyse DM-6.

In order to take a break from working in the lab, Monica Dix (a fellow lab mate) and I toured the perimeter of Lake Erie. We headed east to Detroit, the through Windsor, ON, and drove all the way to Niagara Falls before heading back to Oberlin. Along the way, we tried stopping at as many tourist spots as we could, including a Lake Erie history museum in Detroit, lighthouses, the Great Lakes history museum in Cleveland, and of course, Niagara falls. This was a great road trip, as I was able to see parts of the lake that I never had before, and despite it being winter, the views were spectacular.

Before too long, it was time to leave for Dominica. Amanda, Marcus and I were joined by Malinda Quock from UVM. Day 1 on the island consisted mainly of flying in from Barbados and searching for our Airbnb. The home we were staying at had a beautiful view of Dominica’s capital, Roseau. After settling in, we were able to get in one sample site.

View over Roseau,

 A mother-son pair of dogs that hung out on the property we were staying at,

 Image 3: the view from our first sample site

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The following days were spent rushing from sample to sample trying to get as many in as possible before sunset. Marcus and Amanda provided interesting commentary for each site, remembering what they looked like during the summer, prior to the damage inflicted by the hurricane.

Caption: One of our sites was clogged by woody debris most likely as the result of Hurricane Maria.

                                                         Caption: One of our more beautiful sites was Trafalgar Falls

When heading back home, we had to connect to Fort Lauderdale through Barbados, which meant a day full of crystalline beaches. Our Airbnb host, John, was very hospitable while we stayed with him and gave us a tour of Barbados. We had some delicious coconuts, and I swam in an ocean for the first time.

Now that we’re back on campus, Marcus and I have been sorting and sieving the samples we didn’t quite get to while out in the field. We are preparing some for leaching, and some will be shipped to Malinda at UVM.

As for the future, I will unfortunately be unable to continue working with Marcus as he begins working on his honors project. I will instead be working with Josh XRDing China samples Amanda had collected a few years ago. I hope to increase my abilities in understanding how to interpret XRD data, as I am dead set on become fluent when it comes using XRD-analysis software.

I am truly grateful for the opportunity to go to the Caribbean and assist Marcus with his KECK research. I look forward to what adventures will open up for me in the future.

Thanks for reading!

Ely