Let’s Talk Science: Why Quartz?

03-21-2018

Category: Scientific Work

So, last week on Let’s Talk Science we talked about cleaning up our rock samples to so that they become pure quartz. But why quartz? What makes quartz so important?

Quartz sample from the field.

Quartz is important to us because we use it to determine how old the rocks are!

In order to determine the ages of the rocks we collect, we isolate and measure the concentrations of special atoms inside the quartz, called isotopes. These rare isotopes are beryllium-10, aluminum-26, carbon-14, and neon-21. These isotopes are created in the quartz when they are exposed above the ground.

Figure depicting quartz in rock and cosmic rays from space.

When the rocks are beneath the ground, the special isotopes are not being created. But when the rocks come up to the surface, they begin being hit by cosmic rays, which come to Earth from supernova explosions in our galaxy. These rays go into the rock and hit the quartz, creating our rare isotopes. The rays hit the rocks at a constant rate, so over time, the isotopes build up within the quartz.

Cosmic rays hit the quartz and produce our four isotopes. The heavier the concentration, the older the rock and quartz.

We can figure out how old the rocks are by measuring how much of each isotope is inside the quartz, because we know the rate at which the isotopes are being produced.

Quartz tells us how old the rock is, which tells us something about the ice surrounding it. That’s why we think quartz is pretty special.

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#Quartz #Education #LetsTalkScience