Happy New Year to you all and I hope 2013 brings you some great science discoveries!
Today has been very exciting as some of the samples have been blasted in a miniature furnace! The machine is an elemental analyser for carbon and sulphur, and we call it a LECO (the company name). It is used to extract and calculate the percentage of carbon and sulphur in the rock samples.
This is how it works:
- A small amount of rock powder is placed into a tiny crucible.
- The crucible is placed into a small furnace (called an induction furnace), and heated up to 2000oC in a stream of pure oxygen. This is hot enough to combust all the material within.
- The carbon and sulphur within the rock are oxidised and converted into gas.
- The amount of these gases present is calculated using Infra Red Absorbance Spectroscopy.
Below you can see the LECO machine, a crucible once it has been heated up, and the raw data on the computer screen, giving the amount of carbon and sulphur present.
What are we using the data for?
The data will be used to interpret the environment in which the sediments were deposited. The amount of sulphur can indicate the presence of seawater, and carbon can indicate the amount of plant material or fossil material present. This data will be used in conjunction with carbon and oxygen stable isotopes, sedimentology, palaeontology, palynology and more to build up a complete picture of the environment in which the tetrapods lived.
Since the last blog I have been busy sawing up rock samples and selecting pieces for making thin sections, sieving, palynology, isotope sampling and polishing (see blog 11). I have now processed over 150 samples and along the way I have found many interesting sedimentary features that I just couldn’t see in the field, so it has been worth it.
Before Christmas I went to two conferences in Dublin, the AGM of the Palaeontological Association and the British Sedimentology Research Group. Both were amazing, with a really wide range of talks and tons of exciting cutting edge science. Next week we are having our own small meeting in Leicester for the Tweed project, to catch up with everyone in the group and discuss future research plans. So I hope to give you a group progress report on that in the next post.
Until next timeCarys