View Full Version : Southern Arizona landscape and geology

10-28-2013, 09:23 AM
Hi everyone!

I have a question and would love some help on it.

I'm setting my novel in the south of Arizona. What is confusing me is the geological terms used to describe the landscape. Whatever research I have done thus far speaks about mesas and washes and buttes, but I would like some clearer understanding of how it works; when does the valley end and the mountains begin, for example? What are escarpments and dikes and rills? These are a few examples of the type of words I have come across.

If anyone could help me out I'd really appreciate it. Or maybe just point me to any articles or books that may help as well? Any and all information will be massively appreciated.

Thank you all so much.

10-28-2013, 12:21 PM
Is your viewpoint character a geologist? I lived in southern AZ for a while (Tucson) and have never ever heard someone describe any of the landscape using words like escarpment, dikes, or rills.

Valleys can be in the mountains as well as between the big ranges, it's just a word for a low point. If the low point has lots of big rocks and rock formations, most folks will call it a canyon.

A wash is where the water goes during a flash flood. It can look like a narrow deep canyon in the mountains, a wide flat dry riverbed in a valley (look up pictures of the Rillito river, it used to run year round about 50 years ago, now it only runs during a monsoon rain), or a little dry ditch going through town.

The valley ends when it starts getting hilly and rocky? It's pretty obvious when you're standing out there looking around. There isn't much vegetation to conceal the landscape. Tucson is in a valley. North of the valley are The Foothills where rich people live, and the entire city is surrounded by various mountain ranges. People refer to the ranges by name in that region, and there are a lot of different ranges. It's honestly kind of surreal to me. The Catalina Mountains look like some kind of painted movie backdrop for the city. You can stand in the middle of Tucson, turn in a 360 degree circle, and see five distinct, named mountain ranges.

The big valleys don't have much in the way of large rocks. It's all silty hard packed dirt, with giant calichi deposits you have to jackhammer through if you want to dig down more than a foot.

10-28-2013, 12:49 PM
Thanks Canotila, thats a lot of help. My VC isn't a geologist, I just like being as precise about things as possible, which is a bit of a finicky trait I guess.

Your descriptions really helped in a huge way. I really appreciate it. Especially as my novel aims to end in Tucson; your point about different ranges and a movie set is a great one to remember.

Barring washes, valleys, canyons and mountains, are there any terms I should know? Calichi deposits, for example, is a very new thing to me. I really appreciate this kind of detail!

10-28-2013, 04:43 PM
I agree that if the characters are not geologists or the like, you need not use those terms. My training is in archaeology, which is geology dependent, so I am familiar with those terms. I would not not be that technical.

You can describe most everything with: mountain, canyon, wash/arroyo, valley, cliff, mesa, flat, salt flat, dry lake, hill, rolling hills.

valley-low, slope sided depression toward a river bed cut over time.

canyon- deep steep-sided cut in the land made by a river over time

mountain-geologic feature usually pushed up by tectonic shift. Larger than a hill. Think something that would take a significant amount of time and effort to climb.

Hill- a rise in the land that a person can walk over. Easier to climb and won't take all day.

wash/arroyo- a wash is a shallow cut in the land that is dry except during flash floods. It is cut by rushing flood waters. Arroyo is the spanish word for wash, but common enough that you can use it.

Mesa- Translates to "table" in spanish. It is a flat-topped mountain. Google it to see examples.

flats-flat piece of desert.

salt flat, dry lake. A slight depression/basin in the land that has collected salt. The white color and its location in flat areas make it prone to mirage. From a distance, as a person approaches, it looks like there is water in it, but there is not. I'm not certain that salt flat is a correct term here, verify.

Cliff-A steep face of rock. May be on the side of a canyon or mesa.

Rolling hills, rolling landscape- A series of hills one after another, none of them very steep.

Hope this helps. Familiarizing yourself with the plants of the desert will be equally or perhaps more important.

10-28-2013, 05:05 PM
The vegetation will be way more noticeable than the geology, aside from the major formations. Do a search on the Sonoran Desert and you will get information and photos. Search for "Sonoran Desert - geology" or Sonoran Desert - vegetation" or "Sonoran Desert - Biology" or any other combination that you want to try. Also, you can search for the "Geology of Southern Arizona" or something similar.

The best way to describe the scenery is through the eyes of one of your characters. That will influence the terminology used--is he/she a native or a newcomer? Is he/she educated? Young or old? These kinds of things will influence how a person "sees" the environment.

10-28-2013, 05:08 PM
It's been a long time since I studied geology, but I remember a few things-make that very few. I strive to get the terminology right also, the best with your story.

escarpment: A long steep slope or cliff at the edge of a plateau or ridge; usually formed by erosion

rill: A small channel (as one formed by soil erosion)

dike: An intrusive formation that penetrates another formation; typically volcanic in origin. Sedimentary penetrations are called sills

butte: A hill that rises abruptly from the surrounding region; has a flat top and sloping sides

mesa: Essentially the same as butte

caliche: ca-leach-e A white crust or layer of hard subsoil encrusted with calcium-carbonate occurring in arid or semiarid regions. Usually encountered a foot or two below the topsoil.

10-28-2013, 05:58 PM
These are brilliant and very helpful posts, everybody. I cannot thank you enough. I'll veer away from the technical terms and definitely focus on the plant and wildlife of the region.

IClaytonR, NeuroFizz and jimmymc: thank you so very much for your tips! I shall keep these all in mind. They have been of tremendous help.

10-29-2013, 12:51 AM
note what you've been told; the natrrator is the one who matters here, not an encyclopedic knowledge base. One man's "The baked alkali was littered with Spanish bayonet and creosote bush, and everywhere cactus.." is another man's "The desert was nothing but rock, dirt, and spiny shit, some of it just lame-assed cactus but lots of other stuff he never even knew of..."

the narrator's voice is what matters.

10-29-2013, 06:15 AM
A very valid point, quicklime. Thank you for it. Since the narrative style is more of your former example and less of the latter, it still stands that I'll need some technical knowledge. The tone I'm trying to strike is McCarthyesque, so using terms like alkali and creosote is right up my street.

I do agree with the others in that overly-technical language won't help the reader, though. The key to it (as to most things, I suppose) is balance.