The geologic column and fossil record contained within has been used to support the theory of evolution. How do creationists explain it instead?
The long-age view of the geologic column is uniformitarian, in which the rock layers represent time, and burial order of fossils represents the order of evolution. In contrast, the young-earth creationist explanation is catastrophic, where the rock layers represent a big watery catastrophe (Noah's flood) and the burial order of fossils shows where creatures were carried to and rapidly buried in the flood.
The mainstream geologic column is divided into different epochs and eras in time which the layers are supposed to represent. The creationist geologic column is divided in the same kind of way, but the timescale is very different.
And overview of a creationist geologic column can be seen here http://biblicalgeology.net/Model/Biblical-Geology.html
More detailed classification and subdivisions can be seen here http://biblicalgeology.net/Model/Detail.html
This is of course just one model, which may be helpful for creationists to understand and interpret the rocks.
Short Answer: Catastrophism
"The theory that massive catastrophes occurred in earth's past, substantially altering the Earth and its life via mountain uplift, rapid deposition, and mass extinctions. source"
Young Earth Creationists (YECs) would say that the geologic column was not created via geologic uniformitarianism over a long period of time, but rather through world-wide catastrophes in a relatively short amount of time; the chief catastrophe being the global flood of Noah.
"There is good reason to believe that entire strata systems, and even groups of systems, were accumulated in a hydraulic cataclysm matching the description of Noah's Flood in the Bible." ~ Steven A. Austin, Ph.D. source
Dr. Kent Hovind makes a good presentation in many of his videos, such as these here
Additionally, you can look up Kent Hovind's 7-part Creation Seminar.
Creationists, such as above, point out the various faulty premises. It is also stated that the entire geologic column is not fully represented in all places.
The geologic column was dated well before radiometric dating.
Additionally, fossils which are common claimed to be hundreds of milions of years old have existing specimins today, living (e.g., lobed fish).
Additionally, things such as poly - strata fossils, such as standing trees going through multiple layers of rock and coal demonstrate they must have been laid down within week, not thousands of years, posing the accomodations by a world-wide flood. For example, trees are found both standing upright as well as vertically upside down through multiple rock layers.
The ultimate summary of the geologic column states that the rocks date the fossils, but that the fossils date the rocks (index fossils). As this was based on figures made up long before any radiometric dating.
Additionally, the Mt. st Helen eruption produced mud flows that resulted in canyons with hundreds of layers and "strata", laid down in weeks, not millennia.
All of these point to a great catastrophe, hence, Noah's flood.
Now the flood was on the earth forty days. The waters increased and lifted up the ark, and it rose high above the earth. The waters prevailed and greatly increased on the earth, and the ark moved about on the surface of the waters. And the waters prevailed exceedingly on the earth, and all the high hills under the whole heaven were covered. The waters prevailed fifteen cubits upward, and the mountains were covered.
And all flesh died that moved on the earth: birds and cattle and beasts and every creeping thing that creeps on the earth, and every man. All in whose nostrils was the breath of the spirit of life, all that was on the dry land, died.
The geologic column is a graphic representation of the layers of rock that make up the earth’s crust. By compiling data from local areas, scientists have constructed a composite picture of the earth. Evolutionists would have us believe that this is also a picture of the 4.5 billion year history of the earth. Using a bit of circular reasoning, the geologic column is used as support for biologic evolution, which is then sometimes used to confirm the order of the layers in the geologic column. The use of radiometric dating is also applied to the layers of the geologic record to establish the absolute ages of the layers and the billions of years indicated by the rock layers. In order for life to have evolved, the earth must be extremely old, so the assumption of long ages is applied to the geologic record to support the evolutionary philosophy.
From the biblical creationist perspective, there are several events that must be considered when interpreting the evidence of the earth’s history recorded in the rocks. Just as evolutionists assume that the earth began as a random, molten mass, biblical creationists assume that the earth began with supernatural acts of God—forming the original rocks and layers. These layers and rocks were then catastrophically rearranged and redeposited during the Genesis Flood. As the waters covered the earth, and later flowed off the continents as the mountains rose, the major erosional features, like Grand Canyon and Uluru, were carved out. Modern examples of canyon formation and rapid erosion provide models to explain how many formations can be described by the Flood and its aftereffects—and all within a few thousand years.
The real difference comes down to interpreting the evidence based on man’s understanding of billions of years, or using the Word of God as a starting point. There is no disputing the facts of the geologic record, but the facts don’t speak for themselves. They must be interpreted!
Genesis Answers- Geologic Time Scale
A canyon in six days
Most people are taught that Grand Canyon formed as the Colorado River eroded the landscape over millions of years. The fact that the same results could be accomplished with a lot of water over a short time is generally not mentioned. Observations of canyon formation in modern times suggest that Grand Canyon may have formed much as did a small canyon near Walla Walla, Washington—a lot of water over a short time. During an unusually wet period, a small irrigation ditch was used to divert some excess water. As the water passed through the ditch, it became a gully, then a gulch, then a canyon, 1,500 feet long and 120 feet deep. This all happened in six days, not millions of years. The similar formation of the Toutle River canyon near Mount St. Helens offers another example that is analogous to what would have happened as the Floodwaters receded in the days of Noah.
Creationists recreated a test sample version of a flood, and when the waters receded they found the geologic columns in the exact same order as they are found the earth over where they are said to have been supposedly created over billions of years, yet in their small model version where they flooded a wooded area, the geologic columns this produced after the waters receded were the same as those found the earth over, with the same items in the same order, as in the geologic columns. A conclusion of the items settling in the order they weighted in, was drawn.
Petrified trees in an upright position were found the world over, and in the Creationists test model the loose trees in the wooded area they flooded began to float in an upright position after the became waterlogged.