Paleogeography
(or, what the continents looked like a long time ago)
Below are links to Powerpoint shows made from really stunning maps produced by Dr. Ron Blakey, at Northern Arizona University. By clicking through the slides, you can see how the continents moved and formed in the distant past (the Fade Slow slide transition is important for the effect). Dr. Blakey's website with all the individual images and much more is here. Many thanks to Dr. Blakey for the use of the images.
North America Paleogeography (6.1 MB Powerpoint Show file)
These maps are centered on North America
Southwest U.S. Paleogeography (4.6 MB Powerpoint Show file)
This shows the (speculative) development of the southwest U.S. starting about 1.7 million years ago. You can watch island arcs "crash" into the ancient continent, and the coming and going of the inland seas that were the basis of much of the sedimentary rock in that area. The current location Grand Canyon is denoted by a yellow circle, and helps illustrate why the Canyon has such an abundance of different strata, being often on the margins of those seas.
(If you don't have Powerpoint on your computer, you may download the free Powerpoint viewer here: Powerpoint Viewer)
I went one step further and made movies of these image series, (complete with some tasteful classical music :-)
- it's almost like watching time-lapse films of continental drift from a satellite!
Here are some Quicktime versions:
North America small (3.5 MB)
North America larger (12.0 MB)
Southwest small (4.2 MB)
Southwest larger (14 MB)
(To get the free Quicktime player, go here.)
Also, here are PDF files:
North America Images (3.3 MB)
Southwest Images (5.6 MB)
Please let me know if you have any problems viewing the files. Message me at:
Steve Perrin
sperrin@umich.edu
