author : Ford Cochran

This is the course guidebook that accompanies the 36 lecture “Great Course” of the same name. It is essentially an abbreviated transcript of each lecture, a few pictures, some suggested further reading, and a few questions to consider. (I watched the lectures, which is what I am reviewing here, and am using the book simply as an aide-memoire.)

The geology of North America has been formed by plates colliding, hot spots moving, sediments deposited and eroded, and glaciers advancing and retreating. Mountains, volcanoes, plains, glaciers, wetlands, and canyons abound.

The lectures were accompanied by many stunning photographs (some of which are reproduced in less stunning black and white in the guidebook), Google maps indications of site locations, and somewhat crude and repetitive animations. Watching this, one is left with the idea that most of North America (or at least is numerous National Parks) is home to huge magnificent scenery, most of which was ‘discovered’ about a century or so ago.

Geology appears to be a process of giving different names to essentially the same kinds of rock, celebrating relatively small detailed differences due to local effects, and of giving names to past geographical features: not just continents, but seas, rivers and basins too.

The lectures give an excellent feeling for Deep Time, as process after process after process has constructed the landscape we see today; and these are still going on, most visibly in Yellowstone National Park. One such process results in unconformity: layers of rock are deposited, then are eroded, then more layers deposited, leading to ‘missing’ layers in the geological record. The past didn’t just happen all at once: geology is a process that has been happening continually for billions of years, and will continue to change the face of the planet for billions more.