Aluminum and the 100-year old oceans

I’ve spent more time commenting on other people’s blogs this week than working on my own. I wrote some rather lengthy comments, so I’m going to post them here with some editing.

---

I’ve recently come across several young-Earth creationist recommendations for the book Old Earth Creationism on Trial by Tim Chaffey and and Jason Lisle. I haven’t read the book, but I have paged through it in the local Christian bookstore. It contains little new information, but does contain some of the same old faulty arguments that plague the young-Earth creationism movement. Here’s one example.

On page 124 (if I remember correctly), the authors use the amount of sea salts entering the oceans as one of their proofs that the Earth is young. According to the authors, if one measures the amount of salts (ions, such as sodium, potassium, iron, or chloride) entering the ocean and then compares that to the amount of these substances that are already in the oceans, one can obtain the maximum age of the oceans. I forget the exact number they came up with, but the maximum age they gave is in the tens of millions of years, which is far less than the age of 4.5 billion years given by geologists.

Here’s the problem:

If you use this reasoning with the element sodium (part of sodium chloride), one ends up with a maximum age of 260 million years for the ocean. But there are many other elements in solution in seawater, and using the same reasoning, one obtains the following maximum ages for the ocean:

• K – 11 million years
• Cu – 50,000 years
• Pb – 2,000 years
• Fe – 140 years
• Al – 100 years

Using this sort of reasoning, one should come to the conclusion that the oceans are no more than 100 years old! Something is obviously wrong here. What is wrong is that we cannot determine the age of the oceans by these means because there are other things going on with these elements.

What the authors fail to take into account is the various means by which elements can be removed from the oceans. They mention sea spray, but this is a minor means of removal. In today’s oceans, many of these elements are removed from the ocean over time as seawater circulates through the sediments and rocks in the oceanic crust. Additionally, there are huge deposits of salt in the sedimentary rock record, which is another way in which the various elements have been removed from seawater over time.

What is going on here is not a means of determination of the age of the oceans, but a demonstration of equilibrium. Sodium goes into the ocean, sodium is removed from the ocean at approximately the same rate. The same is true for all of the elements dissolved in seawater.

To summarize: Books like Old Earth Creationism on Trial may seem like a good defense of the Bible to those who know little geology, but are full of poor arguments and should not be used as Christian apologetics. These arguments may be convincing to those without the background to evaluate them, but there are serious problems that the authors either don’t themselves understand or choose to ignore (Chaffey has degrees in theology so his misunderstanding is understandable; Lisle has a PhD in astrophysics and his distortion of science here is difficult to fathom). This is not apologetics but anti-apologetics, and serves to drive scientists away from Christianity rather than pointing them to Christ.

Grace and Peace