The uniformitarian viewpoint is that the layers of sedimentary rock have always been laid down at a similar rate to what we see today, e.g. very slowly. Thus, a given thickness of rock must relate to thousands or millions of years time, based on today's rates.
The catastrophist viewpoint is that sedimentary rock layers can be laid down very quickly and creationists tend to believe that the rocks of the geological column were laid down largely as a result of a global flood as told in the Bible.
Three quarters of the earth's continental surface is composed of sedimentary rock, that is rock that has been laid down in water. It is this type of rock in which fossils are found." WDR
And spared not the old world, but saved Noah the eighth person, a preacher of righteousness, bringing in the flood upon the world of the ungodly; 2 Peter 2:5
