Creationists claim that there is geological evidence that the Grand Canyon was formed as the result of one, or at most a few, flash floods that occurred when water in a huge lake was suddenly released when a lava dam broke. They claim the process was basically the same as the Mount St. Helens eruption, which created a deep channel down one side of the mountain. This, they claim, supports their belief that all of the earth's major geological features were brought about by catastrophic events that occurred in a relatively brief period of time. They argue that their explanation of the formation of the Grand Canyon is supported by the evidence, whereas evidence indicating that it was formed by slow erosion over millions of years is either missing or contrived by proponents of "evolutionism." However, any reasonable evaluation of the physical evidence shows conclusively that the creationist position is completely without foundation.
When Mount St. Helens erupted, one side of the caldera was blown out, and the resulting rush of water from melted snow, plus the blast of hot ash, carved out 300 feet of recently laid loose ash and sediment. area.
To view a topographic map of Mount St. Helens, click here, then click on "Get a Map" and type in latitude = 46.2007 and longitude = -122.1918. Click on "Map It." View at 1:25,000 and also at 1:50,000. The topo map clearly reveals that this washout, described by creationists as a "miniature Grand Canyon," is in fact a large blowout quickly spreading to a wide, shallow channel at the foot of the caldera.
For additional information, click on this talk origins faq.
An excellent publication for the layman is GRAND CANYON the Story Behind the Scenery, by Merrill D. Beal, published by K C Publications, P.O. Box 94558, Las Vegas, NV 89193. This is a 9" x 12" soft cover, 64 page publication with topographic maps and many large color photographs.
The Colorado River is 1450 miles from its source to the Gulf of California. It has four main tributaries: the Little Colorado, San Juan, Dolores, and Green Rivers. The Green River is the main tributary, arising in Wyoming and traveling 720 miles to join the Colorado, 1100 miles above its entry into the Gulf. The Colorado River system is characterized by meandering courses with many U turns. In this respect it is similar to the Mississippi River system. So why does the Colorado system consist of deep gorges while the Mississippi is essentially flat? Because the Colorado River has cut into, and is still cutting into, a rising rocky plateau. The average load of suspended solids carried is almost 400,000 tons per day. [p. 8, Beal publication] This includes heavier material pushed along the bottom. The Colorado acts like a giant conveyor belt, carrying the material to the delta at the Gulf of California. The harder rock walls remain vertical, while the softer rock erodes to form a sloping wall. The Grand Canyon system high plateau extends over thousands of square miles. The geology of this plateau consists of horizontal layers of different kinds of solid rock. Starting at the top and going down, these layers are:
Kaibab Limestone: 300 feet thick, formed in a marine environment. Fossils include molluscs, crinoids, and brachiopods.
Toroweap formation: 200 feet thick, varying from predominantly sandstone to limestone.
Coconino Sandstone, 50-300 feet thick. Sandstone formed from desert sand dunes. Numerous reptile tracks preserved in the sandstone.
Hermit Shale: 300 feet thick. Siltstones formed from deposits in swamps and lagoons.
Supai group: 600-700 feet thick; plant fossils indicate a depositional environment that was low and swampy. Abundant evidence of cross bedding.
Redwall Limestone: 400-650 feet thick. Abundant fossil evidence of crinoids, brachiopods, bryozoans typical of a warm, shallow clear ocean.
Temple Butte Limestone: 100-1000 feet thick. Limestone converted to dolomite.
Mauv Limestone: 150-800 feet thick. Limestone with green micaceous siltstones.
Bright Angel shale: 250-450 feet thick. Shaly green mudstones, with some fine grained sandstones. Many fossils of trilobites, brachiopods, and worms. Gradual transition to overlying Mauv Limestone.
Tapeats Sandstone: 100-300 feet thick. Formed from coastal sand dunes.
Grand Canyon Supergroup: 15,000 feet thick. Angled layers (10 to 15 degrees) of sedimentary rock and interbedded lavas eroded to a horizontal surface prior the deposition of the Tapeats Sandstone.
The fossils occurring in these deposits indicate that the topmost layers are at least 250 million years old, and represent life forms that do not exist today. Limestones are formed by the slow deposition of microscopic marine creatures. There is absolutely no way that these creatures could have laid down deposits hundreds of feet thick in the one year period of the Genesis flood.
There is no evidence to support the creationist contention that the limestone deposits were formed from "chemical rich waters," and no reasonable explanation of how this could have happened. The enormous quantities of limestone present would require concentrations of calcium ions and depths of water entirely beyond any possibility of existing at any one time. They had to be formed slowly over millions of years as microorganisms extracted the dilute concentrations of carbon dioxide present in sea water to form the calcium carbonate which is the main constituent of limestone. Furthermore, there is no mechanism, and creationists have not provided any, to show how the huge quantities of calcium carbonate (limestone) could have been precipitated, especially in the short time frame alleged by young earth creationists.
The geology clearly shows that the Grand Canyon formations were deposited in an environment which existed as a flat coastal marine area for hundreds of millions of years. This region began to be uplifted at the end of the Paleozoic era. At the same time the existing meandering river systems began to cut down into the rock, keeping pace with the uplift over the ensuing millions of years. The Colorado River acted as a "conveyor belt," carrying the material, as it gradually eroded from the canyon walls, into the Gulf of California.
The amount of rock removed was hundreds of cubic miles. Hundreds of cubic miles of SOLID rock! Just to transport that amount of rock (to say nothing of removing it) would require a flash flood consisting of thousands of cubic miles of water! There is no evidence whatever that such an enormous body of water ever existed at an elevation sufficient to result in a flash flood. We are dealing with a flat plateau. Where was the elevated source of all that flash flood water?
Furthermore, how could a flash flood create a meandering river system with four tributaries and numerous U turns in a flat plateau? Did each tributary have its own source of flash flood water?
Faced with the impossible task of explaining how all that rock could be removed in one or at most a few flash floods, creationists have concocted the theory that the Grand Canyon formations were originally mud laid down at the time of the biblical Genesis flood, and the canyons were washed out from these mud deposits by water trapped in some fashion and then released as a flash flood after the flood waters receded. All this is postulated to have taken place only a few thousand years ago.This theory does not explain the steep vertical walls and numerous U turns of the canyon system. Mud does not have the strength to permit vertical walls to be formed by a flash flood, or to divert raging flash floods spreading over a level plain to form meanders and U turns. Weirdly, creationists consider the Mount St. Helens/Grand Canyon argument one of their best examples of refuting "evolutionism." For more information on the Genesis flood argument, click on: Genesis Flood