The Geological Column

Another one for Sirius Knott today, this time concerining the geological column. As ever, and I cannot stress this enough, criticism or corrections are welcomed – if you know more about this than I do and spot an error (or several!), please let me know.

The geologic column (or geologic record) is the sum total of the layers of rock that make up the Earth’s crust (‘strata’), the fossils they contain and any other materials found within them. The column itself is a cross-section of strata, displaying different layers of rocks with different compositions and appearances. The column can tell us an enormous amount about the Earth’s history – its composition over time and in different locations, the tectonic forces that shape it, and the life forms that existed in the distant past.

 

 

 

The Grand Canyon

The Grand Canyon

 

 

 

Unfortunately, the geologic column is never perfect; tectonic activity constantly ‘recycles’ the Earth’s crust through subduction, where one plate is pushed under another and melted. On top of that, there are numerous tectonic processes that can warp the geologic column, in some cases even inverting it. Creationists like to pretend that this is geology’s dirty little secret, but it isn’t; almost any discussion of the geologic column will include this information, and any secondary level Geography course includes the study of these tectonic processes. Despite what Knott seems to think, they are well understood by scientists and are certainly not a serious problem for geology. 

Despite these shortcomings (what Darwin referred to as ‘the imperfection of the Geological Record’), the study of rock layers and their composition is enormously useful. The guiding principle of such study is the ‘Law of Superposition’, which states that ‘Sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top’. The law was first proposed in the 11th century, but is more commonly associated with 17th century scientist Nicolas Steno. 

Before I go further, I must lay to rest one of the most common fallacies associated with the geologic column, and one that Knott commits frequently. It is often claimed that modern geology is built upon ‘evolutionary presuppositions’, and that (non ‘flood’) geologists lie about their data in order to perpetuate ‘Darwinism’. This is nonsense; the order of the geologic column, along with the relative ages of each strata and their associated fossils, were all confirmed long before evolution became a dominant theory in biology. Nicolas Steno himself believed in the Genesis account of a global flood, as did most scientists of that time. However, it was his first steps into dating the rock layers of the Earth that lead to the eventual abandonement of the global flood idea and the eventual discovery of plate tectonics. 

I mentioned the ‘relative dates’ of strata, and here we come to the most contentious area of geology where Creationists are concerned: dating. Flood geology exists because it provides a plausible (for Creationists) explanation for how the various geological features of the Earth could exist in a world that is just over 6,000 years old. There are two general dating principles, ‘relative’ (determining the age of strata in relation to each other, in which the Law of Superposition obviously comes in useful) and ‘absolute’ (which seeks to approximate a sample’s actual age). I’ll go through the more common mistakes that Creationists make about this area of geology:

1) Circular reasoning. Creationists claim that ‘fossils date the rocks, and rocks date the fossils’, which is yet another curious example of them accusing scientists of behaving in a way that is so stupid, one has to wonder why the entire world hasn’t copped on to them yet. Certain fossils are found only in certain kinds of rock layers, and in some cases help to define them (like the Cambrian). These fossils appear so regularly in the same places that they can be used as a reasonably accurate guide to whether a rock layer is of the same era as another, similar one on the other side of the world. Radiometric dating methods confirm these estimates. 

2) Radiometric dating is highly flawed. I’ve covered this one before, but I’ll go over it again briefly. Radiometric dating is the measure of naturally occurring radioactive isotopes and their products, which they produce via radioactive decay (a well understood phenomenon). By measuring the amount of the original isotope present in a rock sample and comparing it to the amount of the ‘daughter’ isotope, it’s possible to obtain a rough estimate of the sample’s age. Creationists object to this method on two grounds: that an assumption must be made about the amount of daughter isotope present in the sample when it formed and that chemical or physical conditions can alter the decay rates of radioactive isotopes.

The first is only partially true; while some dating methods do require one to assume that a sample has not been contaminated by the daughter isotope, isometric dating (more on that in the post I linked to above) does not. The second is completely false; decay rates cannot be altered in this way, and have not been routinely increased by factors of thousands or millions (as claimed by some Creationists) except in certain high energy physics experiments and under conditions that rocks would ever have been subject to during or after their formation. 

3) The fossil record is ‘imaginary’. I’ll go into more detail on the fossil record at a later date, but it is often claimed that the fossil record suggests evolution only if one assumes evolution. This again ignores the fact that rock strata and their associated fossils were discovered long before Darwin ever wrote On the Origin of Species – it took evolution to explain what had already been discovered, and it remains the best explanation for what the fossil record tells us. 

 

There are of course still gaps in our knowledge of the history of the Earth, as there are in any other branch of  science, but major refinements to the geological record are now rare and revisions to ages of strata or fossils tend to go upwards rather than downwards. It is very unlikely at this point that geologists will turn out to have been so wrong as to mistake a six thousand year old Earth for one that is several billion years old. 

Some time over the next two days I’ll adress the rest of Knott’s post, including fossilisation, the infamous Cambrian explosion and flood geology.

EDIT: Knott has apparently reversed his position and no longer wants me to explain why he’s wrong, despite asking me to do exactly that several times, and has gone as far as to suggest that I’m a ‘cyberstalker’ who he wants to get rid of. I’m not entirely sure what to make of that, but his blog is such a rich trove of Creationist propaganda that I’ll continue to base posts off of it, without directly linking to it. It won’t change the content any, since I’ve already decided to cover Creationist mistakes that I had thought didn’t need to be covered.

21 Responses to The Geological Column

  1. Sirius says:

    Are you cyberstalking me, dude?

    You seem a bit obsessed.

    –Sirius Knott

  2. forknowledge says:

    You seemed to want me to respond to your nonsense; I’ve done it here. If you want me to stop, by all means tell me.

  3. Mike says:

    This entry was posted on September 12, 2008 at 10:38 pm

    Sirius Says:
    September 12, 2008 at 10:43 pm

    Are you cyberstalking me, dude?

    You seem a bit obsessed.

    –Sirius Knott

    Yeah, you post to him within five minutes and he’s obsessed with you.

    You’re really not here for the hunting, are you?

  4. Sirius says:

    Mr. Oops!

    You really are a one-trick pony. Repetition does not make your poor excuse of form and substance any less lacking.

    forknowledge,

    In what regard have I “changed my mind” as your EDIT suggests?

    –Sirius Knott

  5. forknowledge says:

    Well, you more or less demanded that I explain exactly why you were wrong on your own blog. You said, and I quote:

    Not another “…the list goes one…” comment! Ech! Weren’t you the one who caqlled ME cliche? You’ve essentially said nothing, except, “You’re wong, man! You just friggin…. wrong!” You’re a credit to Darbots everywhere, pal.

    Care to tell me WHY you think I’m wrong, like the intelligent dissenters who comment on my site?

    So, here you’ve directly asked me to explain why you’re wrong. Which I did. However, on the pingback for that very post, you said (and I quote):

    [Sirius comments: This time he calls me a liar, accuses me a few fallacies and expresses his enduring faith in flawed radiocarbon dating methods.

    Of course, the real question is WHY is he so obsessed with me? How many posts can he make as comments upon the ones I've written before I can legally accuse the guy of cyberstalking? Does he have no original material? How did I become his sodding Muse and how do I ditch this guy?]

    Here you express a desire to ‘ditch’ me, which I can only assume means that you’re no longer interested in what I have to say. Given that my continued (direct) debunking of your posts would apparently land me in trouble of legal proceedings (or was that possibly just a ruse on your part?), I don’t see how my EDIT is unjustified.

    And, for the love of God, it’s radiometric dating. Metric.

  6. Penguin_Factory says:

    You know, Sirius, it doesn’t reflect well on you that you don’t even attempt to address any of the sciencetific facts presented in this post. If your position is really as strong as you’ve claimed to me and others, you should have no trouble refuting any of this.

  7. Mike says:

    FK: This is about par for the course with him. He starts off being the bog old cock o’ the walk, until someone contradicts him, when he immediately turns extremely defensive, especially if someone flat out shows that he’s incorrect. He consistently threatens libel actions and similar if quoted in a way he doesn’t like.

    I found the best thing is to give him a good spanking until he runs away crying and doesn’t come back.

    Oh, and Sirius? If you don’t get the reference to the hunter, it’s from where you got your ass handed to you previously here. Just thought I’d refresh your memory.

  8. Mike says:

    Should be “big”, not “bog”. Yeesh. I swear, if my life ever actually depended upon typing, I’d be so dead.

  9. forknowledge says:

    Don’t worry, I’m the same. A chronic case of typos is called (according to a friend of mine) ‘typoids’. It’s a highly contagious disease.

  10. Mike says:

    I may haev cgauht it.

  11. Tony Sidaway says:

    I found Sirius’s habit of inserting comments and truncating statements using moderation tools very irritating, but not as irritating as his almost complete failure to engage with, or even to address, modern geology. He presents instead a straw man that could only convince the extremely ignorant. Unfortunately there do seem to be a lot of extremely ignorant people around, so people like Sirius preach to their own ignorant choir.

    Having said that, I see little evidence that he has attracted many adherents.

  12. Nathan says:

    Soon to be a geologist’s dream site…

    http://www.rockoutcrops.webs.com

    Through our site you will be able to:

    1. Submit your own rock outcrops to our database.
    2. Find outcrops submitted by other users based on outcrop location or lithologies.
    3. Discuss your experiences through the blog.
    4. Upload pictures
    5. Check out the Geology Links

  13. Sirius says:

    penguin,

    I have already begun responding to forknowledge’s screed on my blogsite, though I’m not quite sure why you guys are so impressed with this fellow’s hubris.

    –Sirius Knott

  14. Mike says:

    We’re actually impressed with the knowledge, although it’s par for the course that you would confuse the two, given your own lack of one and overabundance of the other.

  15. Sirius says:

    You’re quite the little cheerleader, Oops!

  16. Mike says:

    Well, aren’t you the cutest little Creationist? What’s next? Will you stamp your feet and cry?

  17. Tony Sidaway says:

    You know what? I’ll bet if Sirius posted his best evidence for creationism here, forknowledge would let him do it, and would not abuse the moderator tool to intersperse the post with snarky comments.

  18. Luke Maggard says:

    S’up?
    I have a few questions,first i take it your a atheist, and i simply ask why?
    What evidence can you show me regarding evolution that would make me believe it?
    Do you believe that there may have been at one point a world wide flood?
    How do you explain the strata all over the world, across entire continents?
    And wha do you believe the age of our earth really is?

    thanks l.m

  19. Tony Sidaway says:

    Luke Maggard, read a geology textbook.

  20. Akkurat det vet vel de fleste oss at ikke stemmer – det er i
    det store havet mellom de ytterpunktene at nytelsene finnes.
    Det er alltid noen som har lyst på sex i det fri og jeg er helt begeistret av hvor enkelt
    og greit det er å flørte på knull kontakt. De vakre og unge menneskene fra reklamen blir ikke lenger sett på som
    en trussel.

  21. En sex partner er det samme som en knullevenn eller en venn med fordeler.
    Ikke bli sjalu over at ingen tar på deg, men
    len deg tilbake og nyt det du ser. På knull kontakt finner du
    helt sikkert damer som har lyst på det samme som deg
    og som kan tenke seg å ha en het One Night
    Stand ute i naturen sammen med deg.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

%d bloggers like this: