top of page

The Great Unconformity

Updated: May 19

What happened to the missing billion years?

Application: The Great Unconformity Marks the Beginning of the Global Flood.

In this Lesson, Dr. Bob visits Frenchman Mountain near Las Vegas, Nevada and discusses the unique feature geologists call the "Great Unconformity."

Supplemental Information

The great unconformity has baffled geologists for years. It is present throughout the world. It serves as a consistent basement rock, with the sedimentary layers of the Tapeats Sandstone and others deposited on their polished surface. It is called the great unconformity because first, is is an unconformity. An unconformity is a geological term that describes a buried surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In short, there is missing material. This site is referred to as the "great" unconformity due to its presence throughout much of the worldwide sediment strata, and the fact that it represents over 1.1 billion years of missing material in the non-biblical geologic time scale. Non-biblical geologists say the rocks below the unconformity are around 1.7 billion years old. They claim the Tapeats Sandstone immediately above it are ‘dated’ to about 525 million years ago. This dilemma is the result of rejecting the Biblical record as valid history. The Bible presents the most reasonable explanation for the presence of this geological feature.

As the fountains of the deep opened up, and the waters of the global flood began to pour out of the earth, accompanied by the rain falling from the clouds, the destruction began. Sediments that had been created by God in the initial creation week, were now stripped off the surface. The flood waters, now carrying this heavy load of rocks and sediments eroded the surface of the hard foundation rock beneath them.

The rising of the flood water was nothing like filling up a bath tub. There was not a slow, gradual increase in sea level. Rather, the flood waters came in pulses and surges. This is demonstrated in the presence of the great unconformity. It is a polished, smooth surface as a result of the scouring of its surface by wave after wave of destructive water, driven by the fountains of the deep cracking open the surface of the earth and pushing to the surface oceans of mineral-rich water that had been trapped beneath the surface since creation.

Bright Angel Shale Trilobite

As the flood waters continued to rise, subsequent layers of sediments buried additional ecosystems. Wave after wave, ecosystem after ecosystem, scrubbed from the depths of the sea, and the plains and hills of the earth, these sediments were deposited. In another verification of the Biblical account, there are several other unconformities within the Grand Canyon and nearby deposits. These areas include deposits associated with the Ordovician, Silurian, and Devonian (and even portions of the Permian) ecosystems. Because of the extreme nature of sediment deposition, influenced by tidal waves created by movements in the crust beneath the water's surface, some areas received these deposits, and others did not. This fact demonstrates the flawed nature of the geological column represented in most modern geology textbooks. They do not represent slow deposits over millions of years, but are the result of a massive, destructive, global flood event.

To create some context for the effect of the fountains of the deep opening up, consider that if all the current land masses were flattened and spread equally across the surface of the planet, water would cover the entire surface to a depth of almost 9,000 feet (approximately 8,858 feet to be exact). So, while so much discussion of the reality of the flood focuses on the challenges of a water depth sufficient to cover the highest peaks (over 29,000 feet for Mount Everest), in reality this is not a challenge since the mountains rose at the end of the flood event.. In fact, prior to the opening of the fountains of the deep, there may even have been less water on the surface, but with the additional water, somewhere akin to what we have now, there was definitely sufficient to cover all land.

These sequential waves deposited their debris in layer after layer, creating the great sequences of sediments so visible in the Grand Canyon and here at this location. In some cases, the circumstances were favorable to fossil formation, in others they were not, but in each case, the ecosystems were ravaged by ocean waters, and the debris they carried.

In this particular location at Frenchman Mountain, post-flood seismic activity tilted these sediment layers, allowing visitors to touch foundation rock and to walk across the unique sediment packages, and in the process to walk through the flood timeline.

Great Unconformity Worksheet
Download PDF • 1.10MB


Scripture References

  • "And, behold, I, even I, do bring a flood of waters upon the earth, to destroy all flesh, wherein [is] the breath of life, from under heaven; [and] every thing that [is] in the earth shall die." Genesis 6:17

  • "But God remembered Noah and all the beasts and all the livestock that were with him in the ark. And God made a wind blow over the earth, and the waters subsided. The fountains of the deep and the windows of the heavens were closed, the rain from the heavens was restrained, and the waters receded from the earth continually." Genesis 8:1-3

Related Information

Dr. Bob visits the Painted Wall at the Black Canyon of the Gunnison and reviews another unconformity.

1 view0 comments

Recent Posts

See All


bottom of page