Some Geologic Terms for Scrabble Players

I am an avid Scrabble player, and sometimes I have an advantage because of my knowledge of geologic terms. So, as a public service, I here provide some unusual geologic terms for Scrabble players. These are all real terms.

Hoodoo: Geologists sometimes hunt hoodoos. A hoodoo is an erosional form which develops fantastic pinnacles, towers and grotesques shapes. The hard head of hoodoos hold up the formation. This hoodoo on the left is in the Chiricahua mountains. Of course, Bryce Canyon, Utah, is hoodoo heaven.



Tombolo, not somebody’s neck wear, it is an Italian bar – a sand bar that connects islands.


Pahoehoe: ropy lava (first below), not to be confused with Aa which is chunky lava (second below).



Yardang: A yardang is a wind-abraded ridge found in a desert environment.  For instance, Hole-in-the Rock in Papago Park, Phoenix, and Window Rock, Arizona:



Maar: A relatively shallow, flat-floored explosion crater, the walls of which consist mostly of loose fragments of the country rock.

Macaluba: a mud volcano.


Finally my favorite definition.

Cactolith: A magmatic intrusion that solidifies into an irregular shape. Here is the official definition from USGS Prof. Paper 150. Remember I’m not making this up. “A quasi-horizontal chonolith composed of anastomosing ductoliths, whose distal ends curl like a harpolith, thin like a sphenolith, or bulge discordantly like an akmolith or ethmolith.” Now that says it all, doesn’t it, and it provides more words you can spring on somebody.



  1. Hi, Jonathan.

    I am the editor of Forwords, the official magazine of the New Zealand Association of Scrabble Players.

    Forwords is a non profit-making publication, published every three months, and we currently send out about 195 magazines each time. I loved your artcile on the geologic trems – fabulous photos! – and I’m sure New Zealand Scrabble players would enjoy reading it, too.  Please could I have your permission (and Tucson Citizen’s if necesary) to reprint the article in our magazine. I would give due credit to you, of course!  Yours sincerely Jennifer Smith

    1. You may reprint the article.  My understanding is that the authors own the articles so that permission from Tucson Citizen is not necessary.  thanks for your interest.

  2. Hey Jon: Getting va little XXX-Rated, aren’t we?
    The last Hoodoo that I saw was at the Johnny Wadd Film Festival in Hollywood.
    And the bottom Yardang reminds me of my 1st wife.
    Think of the young kids that are reading this stuff, OK? <g>
    Yer pal, Ferrari Bubba

  3. Add End Wry Heat: Hey Jon: If you think that Bryce Canyon, Utah is hoodoo heaven, then you’ve never been to either the San Fernando Valley or Hollywood. Just tell ’em Bubba sent you. You’ll see.<g>
    Yer pal, Ferrari Bubba

  4. That term was coined by Charles Hunt concerning a feature in the Henry Mountains of Utah. He was making a tongue-in-cheek comment about all the “lith” words in Geology. His humor would probably not pass the peer review process these days. Too bad. Personally, I’ve never seen one. Do you have a picture?

    1. I haven’t seen a cactolith either, I think they are hiding underground.
      And a small correction, it was in U.S.G.S Prof paper 228 page 150.

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