Update From The Laboratory!

Hello everyone and happy summer!

We are well underway with our summer work and have been analyzing the cores that we were able to get on our December trip that you made possible. We have both been spending time processing charcoal, and Dulcinea has been hard at work processing and analyzing pollen as well. As we are rapidly moving along with our projects, we wanted to update you with what we are up to and our findings so far. So here we go! We collected a core and a warrah fossil from the Spring Point Farm on West Falkland and collected another core from Volunteer Point on East Falkland, as you may recall.

 

Below is an image of the core collected at Spring Point Farm. This core is being analyzed for charcoal!

 

The charcoal analysis involves a lot of prep work designed to bleach (using hydrogen peroxide) the organic material in each sample so that we are able to easily see pieces of charcoal. The small flask in the photos below contains one cubic centimeter of a core sample in hydrogen peroxide. Each sample is then sieved through a screen and placed in a petri plate (also shown in the photo) to dry the sample in the oven.

 

 

The image above is a sample of the core in a beaker with hydrogen peroxide

Then we are able to use a microscope to observe and measure the amount of charcoal in each sample. Our samples are taken in chronological order moving down the core and thus, further back in time. By measuring the amount of charcoal from each layer of the core we are able to piece together a chronological fire history of the islands. We are both still working on the processing part and are slowly beginning to count the charcoal in each sample. Below are a couple of images of charcoal from the Volunteer Point core collected on East Falkland. These charcoal fragments are likely from burning grasses between 3,000 and 4,000 years ago. Note the grains of sand for scale!

 

 

At this point, we are still in processing and counting stage and haven't been able to put together a charcoal profile for any of our cores. Below is an image of a stack of petri dishes with our charcoal samples ready to be viewed under the microscope!

 

Our hope is to have these done by the end of the summer. Of course, you will be the first to know what we come up with!

Dulcinea is analyzing pollen that is preserved in the core collected from the beach at Volunteer Point. The bottom of this core dates back to about 7,000 years ago and the top of the core dates back to 3,000 years ago. We believe that the last 3,000 years of this record is missing because of erosion. The pollen is isolated from the rest of the sand and organic peat found in the core and each sample is put through a long, multi-step, two day process involving 5+ different chemicals! A couple of examples of the final product are below. These samples are from the part of the core that dates between 3,000 and 4,000 years old. These pollen grains are pig vine (Gunnera magellanica) (top) and diddle dee (Empetrum rubrum) (bottom), which are very common plants in the Falkland Islands today.

 

 

In other news, we sent out 6 warrah bones for dating and were able to get 3 dates out of them! When we found the bones they were stained dark black. At first we weren't sure if this was because they were burned or if it had something to do with the minerals in the shallow lake sediment. Looking at modern sheep bones that were at the surface of the pond, we deduced that it must have been due to minerals in the lake water/sediment because the side in the mud was black, but the side out of the mud was standard bone color. It turns out that the blackening of the bones made it difficult to extract radiocarbon dates, so while we weren't able to date all of the bones, we are thrilled that we were still able to get 3 dates from the bones that weren't quite as thoroughly stained. So here we go, now it is time for the unveiling of the radiocarbon dates, drumroll please……two of the bones date to about 1000 years before present and the tooth we sent out gave us an older date of 3,800 years before present!

 

 

 

This tells us that the warrah was in the Falkland Islands by at least 3,800 years ago. They could well have been there before and we just haven't found or dated older bones yet. We're excited to share that you are the first to hear about these dates and will continue to update you on other findings!

Please leave us a comment or suggestion if you are interested in knowing more about any part of this project! We are happy to share as much as possible!

Until next time!

Dulcinea and Kit