Grand Canyon Cambrian Tapeats Sandstone: How was it deposited? Research by Arthur Chadwick, PhD Collaborators from Geoscience Research Institute and Loma Linda University

Research approach: A good theory in science is one that successfully predicts the outcome of untried experiments Bible can be used to give direction to research efforts in a manner that will yield better results than the standard model Scientists following the Standard Model (millions of years of evolutionary time) have suggested a layer of sandstone in Grand Canyon – the Tapeats Sandstone - was deposited in shallow water over millions of years Biblical model suggests Tapeats may have been deposited in deep water rather quickly

Events at the Grand Canyon 1. Deposit the Tapeats Sandstone Slow, or rapid? 2. Deposit the rest of the sediments 3. Cut the Canyon Standard model – many millions of years Biblical model – could have been rapid

Cambrian Sediments in Grand Canyon Uppermost Cambrian - Muav Limestone Below this - Bright Angel Shale Below this - Tapeats Sandstone = lowest Cambrian sediment in the Grand Canyon region Coarse-grained quartzose sand 100 meters thick Described as Middle Cambrian

Standard model explanation of the Tapeats: Shallow transgressing sea Getting deeper and moving shoreward; suggested multiple cycles of deeper, then shallower Based upon “shallow water” sedimentary structures Based in large part on comparisons with modern environments

Locations of our observations 10 mi

The surface the Tapeats Sandstone was deposited upon was mostly flat, but one very large cliff was present

Below the cliff (background) the Tapeats was deposited with or upon a thick layer of angular rocks (breccia)

Relationship between Precambrian cliff and breccia prior to Tapeats deposition

If it had taken millions of years for the advancing sea to deposit the Tapeats, the sea waves would have destroyed the breccia and the cliff as well

The water had to be deep enough to cover the entire breccia slope all during the deposition of Cambrian sediments – to protect the breccia and the cliff from destruction

Comparison of the models: 1 Comparison of the models: 1. Standard model – slow, shallow marine deposition in advancing sea 2. Revised model – rapid deposition in deep water

Standard model

Revised model

Conclusions : Tapeats was not deposited in a shallow setting. Deposition was in deep water, and was rapid. Sedimentary structures used to define Tapeats as shallow marine need to be reevaluated in the light of these findings.

Conclusions : Research motivated by a biblical worldview resulted in notice of features not recognized by other geologists Careful geological research confirmed the revised interpretation