“It has long been an axiom of mine that the little things are infinitely the most important.” ~Sherlock Holmes
I like to study the little things about rocks, which is why I like microstructures. What makes little microstructures important? Well, every grain got its composition, shape, orientation, etc. by some process, so microstructures give us clues to the kinds of processes that rocks have undergone. For example, if a grain is elongate, perhaps it got that way because it was squished.
Now the squishing of one little grain isn’t earth shattering, but the squishing of millions of grains can move rocks several kilometers! This is how we build mountains. Where the rocks are too hard to squish, they shatter, and if enough of them shatter all at once, they make an earthquake. So in a sense, microstructures really are earth-shatteringly important.
The rocks that I study come from Ontario’s shores of the Georgian Bay, not too far from the land of my heritage, Michigan. These rocks are important because they come from what was deep below mountains that were once much like the Himalaya are today. While we can’t directly measure what is happening beneath the Himalaya, we can study these rocks that are preserved from a similar environment so that we can understand the processes that are building mountains today.
The microstructures that I study are in quartz and I look at them using the cathodoluminescence (CL) detector on a scanning electron microscope (SEM). I have identified several different kinds of microstructures; my goal is to determine what processes formed these microstructures and determine what role those processes may have played in the building of mountains.
(And if you really want to know why I’m studying rock microstructures, it’s because they’re pretty!)