WEBVTT

00:00:00.033 --> 00:00:03.970
Most traces of life get washed away
before they can become fossils.

00:00:05.005 --> 00:00:07.574
However, in the right conditions,
these traces

00:00:07.574 --> 00:00:10.577
can be buried by sediments.

00:00:10.877 --> 00:00:13.880
If enough sediment piles up over
time, heat,

00:00:13.913 --> 00:00:17.951
pressure and chemical changes solidify
the sediment and turn it into rock.

00:00:18.318 --> 00:00:21.021
This process is called lithification.

00:00:21.021 --> 00:00:23.656
These changes happen
deep beneath the Earth's surface,

00:00:23.656 --> 00:00:25.825
where most of these rocks
will remain buried.

00:00:26.159 --> 00:00:30.630
Under the right tectonic conditions
uplift can bring the rocks to the surface.

00:00:33.066 --> 00:00:35.902
Once on the surface, erosion from wind,

00:00:35.902 --> 00:00:38.905
rain, and ice breaks down the rock
layers on top.

00:00:41.041 --> 00:00:43.376
This exposes the rock layers underneath

00:00:43.376 --> 00:00:45.779
and sometimes exposes trace fossils.

00:00:46.046 --> 00:00:47.680
Hi, my name is Sam Shekut.

00:00:47.680 --> 00:00:51.084
I'm a PhD candidate here at the University
of British Columbia, where I study

00:00:51.084 --> 00:00:52.719
sedimentary geology.