<p><strong>Fig. 7.7.</strong> Distinct layers of rock and sediment deposited over millions of years can be seen at Valle CalchaquĆ­ Valley, Argentina. The layers closest to the surface are the youngest in age. The lowest layers date to approximately 65 million years ago, around the time of the extinction of large dinosaurs.</p>

Fig. 7.7. Distinct layers of rock and sediment deposited over millions of years can be seen at Valle CalchaquĆ­ Valley, Argentina. The layers closest to the surface are the youngest in age. The lowest layers date to approximately 65 million years ago, around the time of the extinction of large dinosaurs.

Image courtesy of travelwayoflife, Flickr