The Great Unconformity formed by erosion during the onset of Noah's flood.
This initial breeding pair of and its progeny had life spans of several hundreds of years.
After a lapse of 1656 years (Austin, 19) the creator-God re-appeared as a destroyer-God and caused a world-wide flood that extirpated all living things, except for a remnant which took refuge on a boat called "the Ark", built expressly for that purpose (Gen -6).
Fourth division: The Mesozoic strata represent erosion and deposition as floodwaters retreated.
Third division: The Paleozoic strata comprising the Canyon's characteristic, horizontal strata formed in the early part of the flood.
The essence of is contained in Chapter 4 which divides the strata of the Colorado Plateau into five major groups, according to the ICR reading of the Genesis story (Austin 19-82).