What the heck does Highly Allochthonous mean?

The first thing to get out of the way is the matter of my blog’s title, which has garnered accolades ranging from ‘more difficult to pronounce than Pharyngula’ to ‘awesome geo-nerd term’.

An allochthon is a sequence of rocks which has been superimposed by faulting on top of another sequence which it was originally a large distance away from; for example, a sequence of sediments which were originally deposited in the deep sea, and have then been thrust over shallow marine or continental deposits of a similar age.


Therefore, a ‘highly allochthonous’ sequence is one that has been transported a large distance from its original position (or, more accurately, relative to the fixed ‘autochthon’).

Of course, that doesn’t explain why I chose the term as to appear at the top of my homepage. The pretentious answer would be that the name ‘poetically reflects my aspirations to cover the vast diaspora of disciplines which make up Earth Sciences’. But that would also be a complete lie: the embarrassing, nerdy truth is that it’s just a phrase which formed part of the banter when I was a geology undergrad, and I just thought that it sounded cool. Yes, I am that sad. On balance, though, I think the geeky true answer is preferable to the poncy false answer. Probably.

Categories: bloggery, geology

Comments (15)

  1. J-Dog says:

    From looking at your profile, it looks like you have a nice gig dude… I look forward to getting more autonomous through your allochthonous postings.

  2. Bob O'H says:

    Oh, so it’s nothing to do with cutting up the flag of Mali, then?
    It’s a great name, though. Just don’t expect me to go round telling people about your blog in parties: I have a hard enough time pronouncing words like that when I’m sober.

  3. jon says:

    I’m trying to figure out what you mean by diaspora. Did those disciplines arrive in the Earth Sciences from other science categories? Now what about poncy?

  4. LL says:

    Your new posts no longer get caught by your geoblogosphere tracker…

  5. Chris Rowan says:

    They will shortly, once the aggregator picks up the feed.
    My apologies to any offended readers from Mali.

  6. dmonte says:

    I love the name by I have a bias being a field geologist who loves fold and thrust belts. Been reading for a while and just found your new address. Congratulations

  7. Billy (A Liberal Disabled Vet) says:

    I think (course it was a long time ago, in a state far away) that when I was a kid a Death Valley my Dad (Geologist who went National Park Service) mentioned that Zabreskie Point was one of the most visible alochthons in the United States. However, I seem to remember seeing another one along the Bright Angel Trail at Grand Canyon.
    Cool site.

  8. kim says:

    Just another isolated geonerd who likes thrusting…. join the club

  9. julia says:

    Allochthonous is also an ecological term meaning – ‘from outside the system’. Used in aquatic ecology regarding nutrients. Leaves falling into a stream, for example, would provide allochthonous verses autochthonous nutrients.

  10. Lord Zero says:

    I love it. May i use something as geeky but biologic for
    my own blog. Even if its need a entry to be explained.

  11. Eva says:

    Ah! So *that*’s what it means. You never did answer the “what does it mean” part of the question at ScienceOnline09. (Only made me pronounce it!)

  12. Nick says:

    Don’t think anybody pointed out the roots of the word, greek:
    Allo loosely means ‘outside the self’ whereas
    Auto loosely means ‘inside the self’.
    chtonous loosely means ‘of soil’
    Thus we have allochthonous (I was taught translates to “out of place”) and autochthonous (I was taught translates to “in place”).
    I wonder then, if the modern usages of allochthonous and autochthonous (which Chris’s blog has a correct, but narrow definition) started with geology and then diffused into other sciences (ecology, biology, sociology)…

  13. madalena says:

    in the Netherlands it is used to call people with dutch passport that were born in other countries… definitely not used with the best intentions, therefore i was curious about this blog… it was interesting to know a scientific application of this term 🙂

  14. Geogirldi says:

    I come across the term most frequently associated with salt. For example, the shallow allochthonous salt responsible for the Sigsbee Escarpment in the northern Gulf of Mexico – separated from the source (autochthonous) Jurassic-aged Luann salt much deeper. I can pronounce it ok…I just get tripped up on the spelling sometimes. 😉 Cool title!

  15. Sean says:

    This is an amazing blog. I’m a skeptic that came seeking a scientist’s perspective on Earth’s magnetic polar reversals, and now I can’t stop reading your other articles. Thanks. I like your main logo design as well.