Dinosaur footprints part 4
About two years ago I wrote three posts on young-Earth creationist (YEC) claims of human footprints being found with dinosaur footprints, and the problems that footprint fossils in general cause for the young-Earth catastrophic “flood geology” model.
To their credit, the major YEC organizations, such as Answers in Genesis and the Institute for Creation Research, haven’t used the “human and dinosaur footprints together” argument for a couple decades, but many smaller YEC organizations do.
Answers in Genesis recently put a new article on its website about the formation of dinosaur footprints: Fossilized Footprints—A Dinosaur Dilemma. The article focuses on dinosaur footprints found in Israel in the Cretaceous Judea Group (A “group” in geology is a sequence of two or more sedimentary rock formations).
The footprints are found in a rock called dolomite. Chemically, dolomite (CaMg(CO3)2) is similar to calcite (CaCO3), which is the primary component of limestone. The author correctly states that dolomite forms only in rather exotic environments, such as desert salt flats and hot springs, or in ocean water of rather unusual chemistry. Dinosaurs could not have survived in large numbers in salt flats, and wouldn’t have been walking through hot springs, so the layers of dolomite must have formed from ocean water. Here’s the explanation in the article:
The pre-Flood ocean floor would have been littered with the remains of mollusk shells, in the form of lime. (Mollusk shells are made out of calcium carbonate, the main ingredient in lime.) When the fountains of the great deep broke up at the start of the Flood, massive earthquakes would have caused the ocean waters to rise and sweep in across the pre-Flood supercontinent, like tsunamis, carrying the lime sediments landwards with them.
The water temperature would have progressively increased as hot volcanic waters were added to the ocean. Also, many volcanic eruptions would have added magnesium to the lime-rich Flood waters. This combination of hot water, lime, and magnesium would produce the layers of dolomite. Thus, catastrophic plate tectonics can explain the increase in Flood water temperatures, the inundation of the continents, and the formation of enormous amounts of “marine” carbonate sediments on the continents.
As all of this gets washed up onto the continents, some dinosaurs who have survived the previous parts of the global catastrophe manage to walk around on the newly deposited dolomitic mud.
There are two major problems with this, in addition to the numerous problems with fossil footprints and “flood geology” I have outlined elsewhere.
- Most dolomite in the geologic record is not what we call primary dolomite, that is, dolomite that was formed directly from water solutions. Instead, most dolomite is secondary, formed by the conversion of limestone that was formed in a wide variety of environments. Magnesium-carrying fluids move through pores in the limestone, and react to change the calcite to dolomite. Multiple lines of evidence point to this: obvious recrystallization of calcite to dolomite (the two minerals have different internal atomic structures), studies of strontium isotopes in the minerals, and studies of tiny inclusions of fluids trapped in mineral grains. A quick search on the internet for “Judea group dolomite” brings up articles that discuss all of these as having occurred in the rocks in Israel in which these dinosaur footprints were found. The sediments were composed of lime (calcite) mud when deposited, not dolomitic mud.
- The scenario where volcanoes added heat and magnesium to ocean water as the flood progressed doesn’t work either. First of all, seawater is considerably richer in magnesium than in calcium to start with (though I suppose a YEC scientist might argue that in might not have been so before the flood). Basaltic magma (which must be what is being considered in this model, since the seafloor is made of basalt) is rich in both magnesium and calcium, so I don’t see how this would make the ocean into a dolomite-producing brew. Second, the ratio of dolomite to limestone decreases as one goes up the geologic column. If this YEC scenario were correct, the amount of dolomite should increase as the flood progressed.
I outlined the general problems with the “dinosaur footprints formed by the flood” hypothesis in Dinosaur footprints part 3, where I focused on dinosaur footprints in Jurassic and Cretaceous rocks at Dinosaur Ridge west of Denver:
Here’s what would have had to have happened:
- The flood covers all the Earth, eroding the continents down to their roots. Most erosion, according to this model, would have had to have happened early in the flood.
- At this point, the world-wide ocean was a slurry of water, sediments, and fossils.
- Deposition of thousands of feet of sediments, representing Proterozoic through Triassic rocks.
- Deposition of some Jurassic sediments. Then some dinosaurs go walking around. Then some more deposition. Then some more dinosaurs–a bunch this time–go wandering around. Then some more deposition of sediments. Then more dinosaurs trotting along the beach. Then more sediments. Wait, how did these dinosaurs all survive the previous part of the Flood?
- Deposition of thousands of feet of sediments on top of all of this.
- Lithification of the sediments (changing from soft sediments to solid sedimentary rocks).
- Uplift of the Rocky Mountains, tilting up these layers to a steep angle (they aren’t horizontal anymore).
- Erosion to expose the rocks.
I know that the author of the article read my Dinosaur footprints part 3 post, as it was referenced in the footnotes. This current AiG article did not adequately address objections such as mine, and its “dinosaurs could not have made footprints in dolomite” approach is a failure.
I write this with love and respect for YEC advocates. They love the Word of God, as do I, and share the desire to see people pointed to Christ. However, I don’t think that the whole YEC flood geology hypothesis works—nor is it Biblically necessary—and for many people it drives them away from Christianity rather than pointing them to Christ and his gospel.
Grace and Peace