This phenomenon is seen in some of my other photographs, but not as clearly as here.

This is the eastern slope on Whitemud Creek. It is interesting not only because it shows successive slumping but also because of the two bands that are exposed as result of the slumping. The lower is a black band of coal. The one slightly above the coal, which is almost white, is volcanic ash. This ash is as of a result of a major volcanic explosion that occurred in Oregon at what is now Crater Lake.

Before Crater Lake there was a volcano that blew its top off. The caldera that was formed, later filled with water. However, the ash was carried north and east by the winds and covered most of southern and central Alberta.

This is important for geologists and archaeologists because we know when this explosion occurred, 6,800 years ago. Now we know that everything above the Mazama Ash is younger than 6,800 years old and everything below is older.