Sedimentary Rocks: Video Quiz

The video tutorial introduces sedimentary rocks, explaining their formation through layer compression and the presence of rock beds. It highlights the rock layers at the Grand Canyon and discusses large, smooth rock fragments. The tutorial also covers hoodoos, rocks formed by chemical reactions, and the fossilization process where minerals replace once-living things. Finally, it addresses rocks made from organic materials.

Explain the process in which living things are replaced by minerals.

What are rocks made of once living things called?