ARCHAEOLOGY: Swim Tracks of Global Flood

And the waters prevailed,

and were increased greatly upon the earth;

Genesis 7:18

"In February 2015, geologists Tracy Thomson and Mary Droser, in an article published online by the journal Geology, released graphic evidence for the reality of Noah’s Flood.

The Geological Society of America press release shows a sandstone block sitting vertically in the field with tracks running for a few metres across its surface. These are interpreted as swimming tracks because the imprints represent only a part of the foot. Consequently it is assumed that the animal was being supported by water. Thomson and Droser explain:

Swim tracks are a unique type of vertebrate track because they are produced underwater by buoyant trackmakers, and specific factors are required for their production and subsequent preservation.

 Swim tracks are found all over the world, including dinosaur tracks in northern Spain, which consist of claw marks made on the sand surface as the animal was on tip-toes trying to move through deep flowing water.

Thomson and Droser note that there was something unusual about this period of earth history because of the number of tracks made by animals swimming in shallow water:

Early Triassic deposits contain the highest number of fossil swim track occurrences worldwide compared to other epochs, and this number becomes even greater when epoch duration and rock outcrop area are taken into account.
This spike in swim track occurrences suggests that during the Early Triassic, factors promoting swim track production and preservation were more common than at any other time.

This situation is easily explained by Biblical geology. In broad terms, this portion of the geologic column represents the period of Noah’s Flood when the floodwaters were rising toward their peak, which occurred somewhere around the top of the Cretaceous. Indeed, there was something unique about this period of earth history, because a global flood has never happened since.

Thomson and Droser describe another characteristic of the sediments deposited at this time that is consistent with Noah’s Flood:

… sediment mixing by animals living within the substrate was minimal, especially in particularly stressful environments such as marine deltas. The general lack of sediment mixing during the Early Triassic was the most important contributing factor to the widespread production of firm-ground substrates ideal for recording and preserving subaqueous trace fossils like swim tracks.

This reworking of sediment by burrowing animals is often called bioturbation.

The good preservation of the tracks is another feature that Thomson and Droser discuss:

Lower Triassic swim tracks also tend to be better preserved, showing exceptionally detailed features such as scale striae and crescent-shaped claw margins. Preservation of these features required a firm and semicohesive substrate in order to maintain track detail before and after burial.

Tracks and impressions are quickly removed from beaches and deltas today, as changes in water level driven by waves and tides erode the tracks, and the drying of sediment means the tracks would crumble away. Waters in estuaries and on beaches today are relatively clean, with low sediment content and low dissolved salts. In order for tracks to be preserved the substrate needs to become firm, and that would need some sort of cementing action. By this stage in the Flood, the rising floodwaters would contain much material that would act as a cementing agent. (Videos of modern day tsunamis give an idea of the contaminated condition of the water as it flows onto the land, and the waters of the mid-Flood may have been significantly more contaminated than this.) This water would be incorporated into the pores of the deposited sediment, providing conditions for rapid cementation, causing the substrate to quickly become “firm and semicohesive”." CMI