An Introduction to Geology: 2014
Week 9. Fossils.
How to tell bone from stone: Smithsonian magazine article by Brian Switek.
The Fossil Record of Cricket (an article I wrote for ESPN Cricinfo). I later wrote another on the evolution of fast throwing.
Weeks 6. & 7. TECTONICS
The day the Earth moved – very interesting article in Cosmos magazine describing the revolutionary times of 1963, when tectonic theory came to the fore.
The Moho (or, more properly, the Mohorovičić Discontinuity) is the boundary between the crust and the mantle. It is not the same as the boundary between the lithosphere and aesthenosphere, because the lithosphere includes the solid upper mantle.
Much of the lower mantle is thought to be composed of a (newly named) mineral called bridgmanite.
There is also new evidence, including a recently discovered terrestrial sample of a mineral called ringwoodite, that the lower mantle (410 to 660 km below the surface) has considerable volumes of water trapped in it.
Both bridgmanite and ringwoodite are varieties of olivine, as explained in this helpful article.
Week 5. A BIT MORE TIME
Here are a few 2014 additions to all the existing ‘IntroGeol’ files already on the site, as follows:
Lecture notes for Class 5 “A Bit More Time”
The Rock Cycle
An excellent, rather more detailed version of the rock cycle, illustrating the subdivisions of the different sections, can be seen on the Geology Cafe website here.
The 2014 edition of the geological time scale, produced by the International Commission on Stratigraphy (ICS) can be downloaded here.
If you want details of where in the world any of the Global Boundary Stratotype Sections and Points (GSSPs) are, Wikipedia provides a pretty comprehensive list here. It is based on the International Commission on Stratigraphy’s list, which can be found here.
For more information on clay minerals, also known as sheet silicates, also known as phyllosilicates (literally ‘leaf silicates’, deriving from the same Greek origin as ‘filo’ pastry), these course notes by Prof. Stephen Nelson of Tulane University are very helpful.
An excellent Conversation article on why the discovery of clay minerals on Mars is rather important.