Geology Reference
In-Depth Information
hikers heading down the trail, I could see 270-million-year-old fossil coral and mollusks
that reminded me of the complexity and diversity of life I'd seen learning to scuba dive on
Australia's Great Barrier Reef. Finally, I reached the top.
Standing on the rim, I reviewed the story I read hiking up through ancient
worlds—missing mountains, shallow and deepwater seas, coastal jungles, windswept sand
dunes, and coral reefs. The few simple organisms in the lowest layers offered an obvious
contrast to the complex reef community at the top. I had completed a grand tour through
geologic time telling of the rise and fall of ancient mountains and seas, with the rocks at the
bottom reaching back to the dawn of life and those at the top predating the dinosaurs. That
the cliffs were solid rock right up to the canyon rim testified to erosion of all the formerly
overlying rock that provided enough pressure to solidify a pile of sand and mud in the first
place. Whole worlds came and went before the one we know today.
One doesn't need to hike up through thousands of feet of rock outcrops to refute the no-
tion that the Grand Canyon formed during a flood that somehow managed to lay down all
those rocks right before carving through them to create the canyon. A simple experiment
you can conduct at home will prove the point. Get a glass-walled box (a fish tank will
do nicely), fill it with water, and pour in a mix of clay powder, sand, and pebbles. Larger
particles and denser material will settle out first, forming a pile with pebbles on the bottom,
sand in the middle, and clay on top. Then, pour in rocks or sand all of the same grain size
but a mix of colors, and you'll get a collage for a deposit. In order to sort by color, you
have to add one color at a time. The rocks exposed in the walls of the Grand Canyon could
not have settled out during a single flood because they alternate many times in color, grain
size, and composition.
Something that really struck me about my hike up the canyon was how the plants and
animals entombed in the walls of the canyon are extinct. If all the creatures buried in that
mile-high wall of rock had been put there by the biblical flood, then why aren't modern an-
imals entombed among them? That the vast majority of fossils are extinct species presents
a fundamental problem for anyone trying to argue that fossils were deposited by a flood
from which Noah saved a pair of every living thing.
A simpler, fatal problem for the creationist interpretation of Grand Canyon geology is
that sandstone, such as the cliff-forming Tapeats and Coconino formations I hiked past,
