And this is our rock preparation room.
We got these from John Whitmore,
from the base of the Grand Canyon.
But initially, we need to cut these rocks,
dry them,
and get them prepped for thin section analysis.
All right. This will be noisy.
Okay. Right now, I'm going to put an orientation mark on this rock
to show what end is up.
That will be crucial to determine how the bedding structure is affected
by how the rock materials originally were laid down.
That sample is now ready for drying
in preparation for
liquid epoxy impregnation in this sample.
Many professional geologists aren't
aware of how to do this process.
There are only a handful of people, perhaps in the entire world
who know how to do this kind of thing,
at least to do it well.
Literally a handful of people.
Okay. The epoxy is used for stabilizing the sample,
filling the pore space, and stabilizing the fine material
that's found in the pore spaces.
So this is a high pressure cell
which we use to inject the liquid epoxy
into the pore spaces in the sample.
In the morning, we can retrieve it.
The epoxy will be solidified
and then we can handle that piece of rock safely
all through the rest of the next part of the process.
What we're doing now is taking the epoxy
away from the bottom surface and we're exposing the rock
that's been impregnated with blue dyed epoxy.
And so what that does is allow us
to get a nice flat, optically planar surface.
And in this case, it's extremely important
we're not mistaking scratches for fractures.
So we don't want to leave scratches in the rock surface.
We want to make sure that all the scratches are out
so that the fractures can be easily identified.
Okay. So we're going to move on to the staining process
and then it will be ready for mounting to glass.
We don't want to induce any kind of fracturing into the sample.
And so mounting this to glass, using the Cyanoacrylate glue,
Krazy Glue, ensures that we have a good, stable surface with which to work.
Imagine trying to work with a single piece of hair
and trying to grind it without affecting the character of the hair.
We want to make sure that we don't disturb the mineralogy of the sample
as we go through the cutting and grinding processes.
This slide we will now take to our grinding laps
where we'll thin it down to about 30 micron thickness.
This is kind of where the art comes into play.
Do just a quick look in the microscope here...
and it looks like we're pretty well at 30 microns thickness
all the way across the entire thin section.
We have the grains seen as being very clear
and, in across polarized light,
showing either as a gray
or as a pale straw yellow.
And that tells us that we're right on the 30 micron thickness.
Back in the day when we were really busy,
we would do anywhere between 80 to 100 of these types of samples a day.
Personally, I've probably done in the order
of about 20,000, I guess.
I'll take the slide and
look at it under the good petrographic microscope,
which is a special kind of microscope made
for analyzing geological thin sections.
And there are a lot of interesting features to be seen in this thin section.
And so the thin section processing will allow us to determine
textures, mineralogy, porosity.
Those are the sorts of things that we're trying to derive from this
small piece of rock.