Some questions for the day...
1. How do diamonds form? Specifically, what combination of events are required for diamonds to exist at Earth's surface?
2. What are the differences between the carbon polymorphs (graphite and diamond) in terms of physical properties such as density and hardness, type of chemical bonds present, coordination polyhedra for carbon?
3. What is the stability region of diamond in PT space/ Why does diamond turn into graphite during normal upwards mantle convection? Why is the mantle beneath ancient cratons suc a good place to form so many of the diamond that evetually make their way to the surface of the Earth? What is a kimberlite pipe? How is a kimberlite eruption different from a "normal" volcanic eruption?
4. How long ago were most diamonds found near the Earth's surface formed? How long ago did most preserved kimberltie eruptions occur? Why is it interesting that there is a huge gap in between the respective time periods?
5. What does LLSVP stand for? Can you use LLSVP in a sentence? Why do we care about the shear wave velocity of the lower mantle? Why is it interesting that there was a large LLSVP underneath the diamond-bearing portions of Africa?
6. Two recent (2011) papers have discussed the isotopic composition of diamonds and mineral inclusions in diamonds. While not necessarily presenting information on how most diamonds form, what interesting observations and conclusions where these papers able to make?
Slides from lecture are on Sakai...
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