WORLD is a biweekly news magazine with a Christian perspective.
The author of this article, Marvin Olasky, accompanied 5 YE creationists on a rafting trip on the Colorado River through the Grand Canyon, and relays their views on the geological features.
Atop that are a series of mainly sedimentary layers (Bass Limestone, Hakatai Shale, etc), along with the igneous Cardenas basalt.
These now-tilted layers, collectively termed the Grand Canyon Supergroup, have a total thickness up to 12,000 ft.
There is a cadre of YE creationists with scientific credentials who publish articles which claim that mainstream science is mistaken on matters such as the age of the earth.