Tomorrow is the big day…the day we’ve all been waiting for…the day we split the sediment core!
If you’ve read your way through my blog, you’ll know that right now, the core looks like this:
The core was sampled from the bottom of Little Sugarloaf Lake in the summer of 2015, and ever since it was shipped from Greenland to the Axford lab on campus, it’s lived in its coring tube in a huge walk-in freezer. Looking through the plastic, there’s very little we can learn about the core. Basically, we know that the dark brown color indicates a lot of organic material, and that’s about it.
But tomorrow, we’ll split the cylindrical core in half (to give us two half-moon shaped slices of sediment), allowing us to see what’s inside and look at it in two ways. First, we’ll give it a good old-fashioned visual inspection. Are there any places where the color changes? What about the texture? Are the changes stark, or gradual? We’ll also look to find anything we could send out for radiocarbon dating (especially animals’ shells) to get some boundaries on the age of the core.
The more exciting way of looking at the core will be to use the Axford lab’s brand new very shiny Geotek core scanner (installed in the lab today!!). It looks a lot like this…
…and, for scale, I don’t think it would fit in my bedroom! This magnificent metal giant can do just about any analysis anyone would think about doing on an intact core. It takes incredible high definition photos, converts colors to numerical data to more precisely identify color changes, scans for the abundances of numerous elements, and tests for magnetism, among multiple other functions. Gathering all this information will only take a couple hours at most, and it’ll help me get a fuller picture of what the core contains. I’ll be keeping in mind what I learn when I start to explore the biomarkers that are preserved in the sediment, and try to interpret what they mean.
Splitting and scanning the core will start the ramp up top what I’m calling Phase Two (does that give it a top-secret very-important-science vibe?). Phase One, which is starting to wrap up, was the process of extracting, chemically separating, and analyzing the plant samples. I’m very close to having a complete set of data about the plants’ lipid chain lengths and their isotope ratios, so in not too long I’ll be able to analyze and interpret these data, looking for how different groups of plants may have different chemical signatures. But Phase Two is where I’ll get the opportunity to look into the past, traveling back in time as I extract sediment from deeper and deeper in the core (i.e., deeper and deeper layers of mud from the bottom of Little Sugarloaf Lake). Stay tuned for when the time travel begins!