My strict young-earth creationist position began seriously to unravel in the summer of 1982. A year into my graduate studies, I was invited by Dr. Robert R. Reisz at the University of Toronto to join his field crew quarrying in Pennsylvanian-Period sedimentary rocks near Garnett, Kansas.
We were searching for the fossilized remains of pelycosaurs (mammal-like reptiles, a group to which the well-known sail-backed Dimetrodon belongs). Their skeletons were preserved in fine-grained and very thinly laminated (bedded) siltstones.
As we chiseled and split our way down through the layers, we found the fossilized remains of both plants and fish. In addition to these, we exposed many layers that preserved the fossilized footprints and trackways of both large and small tetrapods, i.e. four-footed animals.
Fossilized trackways, impressions, footprints, burrows or other markings left by once-living organisms are referred to as trace fossils. We collected many of these trace fossils, since much can be learned about how an animal moves, among other things, by studying the traces it leaves behind.
These trace fossils really got in our way, however, because they slowed down our efforts to reach for the fossils Dr. Reisz was really after. They got in my way personally as well. It would be difficult for me to overstate the impact these simple fossilized footprint impressions had upon me. In retrospect, I don’t think anything else I have ever seen has so profoundly changed my life.
If all sedimentary rocks, and the fossils within them, were the result of the Flood, how, I wondered, could these fossil footprints have been made? All living land-dwelling animals were supposed to have been drowned in the Flood (except those on the ark, of course). Certainly none were walking around underwater leaving footprints! The trace fossils I was seeing had to have been made after the Flood, or perhaps even before it. It was forcefully obvious to me that not all sedimentary rocks came about as a result of the Flood.
How, then, could anyone know which sedimentary layers were the result of a world-wide deluge, and which resulted from local or global pre- or post-flood phenomena? Posed with this quandary, I began to accumulate literature back at McGill on the occurrence of track or trace fossils in other parts of the world. One of the final nails in the coffin of “flood geology” came for me when I realized that fossil tracks and traces made by terrestrial animals occur at countless levels throughout sedimentary rock formations all around the world.
There was no conceivable way to account for the occurrence of all of these animal trackways in rocks that had been deposited by a Flood which was supposed to have killed all the animals capable of making the trackways. Trace fossils don’t sort hydrodynamically or by ecological zonations! Footprints of terrestrial animals are made when the mud or other soft sediments they are stepping in form the outer-most layer of the earth’s surface. To be preserved and incorporated into the fossil record, an existing footprint must be covered very “carefully” under calm environmental conditions, not those characterizing a global flood.
The existence of multiple footprint layers in one location would demand the fortuitous combination of animals walking over plastic (soft deformable) sediments, followed by the burial of those footprints by sediments under conditions that would not destroy them in the process of burial. This process would have to have repeated itself at least as many times are there were distinct layers of footprints in one area.
Furthermore, different kinds of animal tracks appear at different levels in the geologic column. For example, we don’t find moose tracks running all the way up through the geologic column, as we might expect if these trace fossils were made as these animals ran for higher ground during the opening days of Noah’s Flood.
If I knew only about trace fossils and had no other evidence for the great antiquity of the earth, I would still be able to conclude confidently that the world’s sedimentary rocks were not the product of one gigantic, year-long flood. The presence of these delicate footprint fossils also proved to me that fossilization was not necessarily the result of a catastrophic event.
I often thought in those days of the analogy that had come to me years earlier between layers of snow along the side of the road and layers of sedimentary rock. Years later, I observed footprint fossils on layers that also preserved fossil mud cracks. The cracks proved that these were sun-baked sediments, which could hardly have been formed during Noah’s Flood!