Uniformitarianism or Catastrophic process?

Within the study of geomorphology, the concept of uniformitarianism (the idea that

geography only changes over long timer periods) has been the dominant theory. On May 18,

1980, the eruption of Mt. St. Helens and the consequent geomorphic shifts it produced, may

have changed all of that. Dr. Steve Austin, who has been studying the eruption, has noted

three incredible things.

Rapidly formed stratification'– multiple layer in a rock bed have generally thought to have

been formed over many years, however, as Dr. Austin noted “A deposit accumulated in less

than one day, on June 12, 1980, is 25 feet thick and contains many thin laminae and beds.”

(Austin, 1986)

Rapid erosion'– “Mudflows, from Mount St. Helens, were responsible for the most

significant erosion. A mudflow on March 19, 1982, eroded a canyon system up to 140 feet

deep in the headwaters of the North Fork of the Toutle River Valley, establishing the new

dendritic pattern of drainage.” (Austin, 1980) This mini river has the same geomorphic

features as the Grand Canyon.

Upright deposited logs'– “Hundreds of upright floated and deposited logs have been

grounded in shallow water along the shore of the lake. These trees, if buried in sediment,

would appear to have been a forest which grew in place over hundreds of years, which is the

standard geological interpretation for the upright petrified "forests" at Yellowstone National

Park” (Austin, 1986)

His conclusion is that “Mount St. Helens provides a rare opportunity to study transient

geologic processes which produced, within a few months, changes which geologists might

otherwise assume required many thousands of years. The volcano, therefore, challenges our

way of thinking about how the earth works, how it changes, and the time scale we are

accustomed to attaching to its formations.” (Austin, 1984)

References

Austin S., (1984). Rapid Erosion at Mt. St. Helens.'Origins, 11, 90–98.

Austin, S. A. 1986. Mt. St. Helens and Catastrophism. Acts & Facts. 15 (7).