The Law of Superposition, or do Rock Layers Equal Time Charts?

OK, kids, let’s go along on a typical talk about the formation of sedimentary rock. It’s just 37 seconds long, so listen close. Here’s the question: How does he know it takes between 10,000 to 20,000 years per layer to form?

If he’s right, how old must the lowest visible rocks in that valley be?

Does God give us anything like that much time to work with?

Can scientists actually do any studies to find out who’s right?

Let’s find out!

For over 300 years geologists have assumed something called the

Law of Superposition: Dictionary Reference.com

Geology . a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

Makes a lot of sense, doesn’t it? In fact, it was first described by a young earth creationist. One way to teach the basic idea is by comparing the rock layers to the stuff that collects in your school locker.

But, I bet you can start to see the problems Uniformitarians get themselves into already. They don’t consider it possible to drop off a whole pile of papers at once. Instead, they assume every sheet of paper shows a little piece of time- even if they’re in a set, like a book. Using their system, all you’d need is a couple books at the bottom of your locker to “prove” you’ve been using the same one for over a year!

I’m not being silly or putting words in their mouths. Let’s see this in action:

One favorite example of sedimentary layers used as clocks is in something called the Green River Formation. There are so many layers it is said to have taken somewhere around 8 million years to develop. But, to see that much time, they have to assume [just consider as true] each tiny layer took a whole year to form.

Biblical Creationists aren’t about to agree with something like that. Since the whole world is less than 10,000 years old, it’s not possible for rocks to be older than that. So, are we all stuck in a mess like little kids saying, “it is!” It isn’t!” Is too!”?

Nope, there are some awesome ways to tell whether one view fits the science better than the other.

Back in 1980, a full scale experiment was done for scientists to watch in real time: Mount St. Helens. I’ve written about the book and videos talking about the huge number of layers the mud flows and ash laid down in just a few hours. Thousands and thousands of layers. In hours.

Fossil Fish from the GRF of Colorado.

And this is just the beginning! Those Green River layers are full of fossils, mostly fish, but a lot of birds too. Lots of these fossils stick up through several layers.

If it took a year to form each layer, those fish would have to stay fresh for several years before being fossilized. Not possible!

PS, the Institute for Creation Research has a really cool fish fossil from that formation. It still has fresh tissue in it. 😀

We’re just getting started and I’ve run out of room. Today let’s close with a couple examples of how important this whole idea is to Evolutionary thinking:

Evidence for Evolution slideshow. The Law of Superposition shows up on the very first page!

The Smithsonian has a detailed description of how Stratigraphy (the study of rock layers) is a “Foundational Concept” in the evolutionary time story.

I am the LORD: that is my name: and my glory will I not give to another, neither my praise to graven images. Isaiah 42:8 

Watch for Part 2, A Geology Student’s Experience, and Part 3 coming soon