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Fantastic Ventifacts

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Ventifacts are such a broad subject! I'm having a hard time finding the first words to write. I'd like to show you the pictures right now, but there are so many things to address before that can happen.

If you are a person who came a long distance, possibly from a galaxy far far away, you came here to learn about such all-important things as what exactly ventifacts are, who created them and why. You might also be angling to learn where you can find a few neat pieces for your personal collection (of memories).

Calm down, they're just rocks!

What are ventifacts and who created them?

Ventifacts are rocks that have been smoothed and shaped over time by wind and ice crystals.

Coachella Valley field trip video

They are an everyday sight in most deserts of the world, the tundra biome, and have been identified on Mars.

Ventifacts are formed by sand-blasting, which is an effective means of erosion, both in nature and as a way for cleaning buildings and surfaces in preparation for painting. Sand-blasting was first discovered in a geological context in 1855 when geologists described wind-eroded features in the Coachella Valley of southern California in a study of aeolian processes.

Coachella Valley, California. Click the link to Discover more photos of Garnet Hill.

Coachella Valley, California. Click the link to Discover more photos of Garnet Hill.

The term ventifact means "wind-made." It was coined in 1911 by a British geologist when he was performing field work in arid regions of Africa and Asia. The terms describes any wind-modified object and does not apply exclusively to erosion by wind-blown sand.

Ventifacts can be recognized by many features, ranging from wind-cut faces - called facets, - polished or etched surfaces, to features such as pits, flutes, and grooves. They come in many sizes from grains a few millimeters across to huge rocks over 3 m long.

Ventifacts in Antarctica

Ventifacts in Antarctica

More awesome photos of ventifacts in Antarctica by RubyWhatever.

Where can I find ventifacts?

You can find ventifacts where aeolian processes have been occurring, such as in arid regions, glacial plains, or along coastlines.

They are more easily formed given a moderate but steady supply of sand and silt particles for abrasion, strong enough winds to move them, and vegetation that does not impede the wind-blown particles before they could affect the rock surface.

Glacial plains are especially well-suited to produce ventifacts as evidenced by a multitude of them in parts of Antarctica and Iceland.

Since these conditions can also be found on Mars, you should expect a big ventifact population, even though they might not be easily recognized from where we are.

How ventifacts are formed on a hill slope. Click to enlarge.

How ventifacts are formed on a hill slope. Click to enlarge.

Ventifacts are widespread in the deserts of North America. They have formed on the slopes of desert lakes that are almost always dry except after exceptional rainfall. Much of their basin is covered by a veneer of wind-blown sand.

When windflow approaches a hill, airstream compression accelerates it and increases the speed and volume of sediment transport. A back-flow eddy is created on the lee slope.

The actual speed-up increases the volume of sand transport and causes ventifacts to form on dune and hill slopes.

In the picture, there is a strong northwest wind that develops ventifacts over 2/3 of the slope while the weak but also accelerated southeast wind forms ventifacts only near the crest. The intensity of ventifaction - meaning the depth and width of grooves - correlates well to wind velocity up the slope.

Below is a map of North American deserts.

what-are-ventifacts

Ventifact Morphology

Ventifacts are of many different shapes, including prolate, oblate, pyramidal, triaxial ellipsoidal, or irregular forms. Wind-cut surfaces are either curved or flat (facets), and edges are either angular or rounded. Since multiple facets are not uncommon a hierarchy of terms has been suggested to describe facet arrangements - einkanter, zweikanter, driekanter, etc., meaning one, two, or three corners, etc. In fact, ventifacts can have up to 20 facets.

Why do multiple facets develop?

They can be a result of a variety of circumstances such as multiple wind directions, shifting of the rock to present new surfaces to abrasion, as well as complex patterns of air flow and abrasion by suspended particles.

Ventifact morphology is a useful way to map active wind patterns from currently active ventifacts and paleowinds from fossil ventifacts. The main facet usually faces the prevailing wind and pits are commonplace on these surfaces.

However, the use of a single ventifact to identify wind directions is inaccurate, because ventifacts tend to shift orientation over time. It is necessary to map a large number of ventifacts to determine wind patterns that corroborate the measurements of the active winds.

This Garnet Hill map shows the orientation of ventifact surface features that disclose the wind patterns over the hill.

This Garnet Hill map shows the orientation of ventifact surface features that disclose the wind patterns over the hill.

Diagram showing the three factors at work.

Diagram showing the three factors at work.

In order to calculate wind abrasion rates, researchers always need to look at three principal factors:

  1. wind frequency including strengths and durations,
  2. particle characteristics such as velocity, flux, etc.,
  3. susceptibilities to abrasion for a variety of ventifacts.

Ventifact Beauty Contest

Welcome to the first ever Ventifact Beauty Contest!

Now that you know everything that you never wanted about these fantastic creatures, it's time to get to the main attraction of this hub.

Although beauty contests often incorporate personality, talent, and answers to judges' questions as judged criteria, we decided against bothering with all that and are focusing solely on the physical beauty of our contestants.

So lets get down to voting for the most beautiful, most stunning ventifacts of the world! Here are your contestants:

Miss United States -  Death Valley, United States

Miss United States - Death Valley, United States

Miss Antarctica, Dry Valleys, Antarctica

Miss Antarctica, Dry Valleys, Antarctica

Miss Bolivia - Arbol del Piedra, Bolivia

Miss Bolivia - Arbol del Piedra, Bolivia

Miss Norway - Snømannen, Balsfjord, Norway

Miss Norway - Snømannen, Balsfjord, Norway

Miss Serbia - Djavolja Varos, Serbia

Miss Serbia - Djavolja Varos, Serbia

Miss Peru - Colca Canyon, Peru

Miss Peru - Colca Canyon, Peru

Miss Fiji - Matei, Fiji

Miss Fiji - Matei, Fiji

Miss United Kingdom - North Yorkshire, UK

Miss United Kingdom - North Yorkshire, UK

Miss Australia - Hargraves Beach, Australia

Miss Australia - Hargraves Beach, Australia

Thanks for the hub idea, Ardie!

Comments

jessy on November 03, 2011:

Hi so thankx of you

I Nyi Nyi

Haunty (author) from Hungary on October 21, 2011:

Well, I haven't seen it with my own eyes, so I suspect the same. What sort of winds could possibly shape such a rock in the UK? The UK is very windy, granted. But this?! :)

Sondra from Neverland on October 21, 2011:

All the "apple"-shaped women of the world thank you for the recognition :D Now Miss UK? There's no way that's all real - I suspect a little nip/tuck if you get my drift.

Haunty (author) from Hungary on October 21, 2011:

She can't help what?! She is awesome!! I haven't voted yet so I'm going to vote her just to show people that being pyroamid-shaped is awesome.

Sondra from Neverland on October 21, 2011:

Before you add anyone else to the group poor Miss United States needs a vote! I better go promote her cause, poor old gal. She can't help who she is...

Haunty (author) from Hungary on October 21, 2011:

Thanks doodlebugs! Someone should indeed photograph them and allow me to add a Miss Canada.

Nolen Hart from Southwest on October 21, 2011:

Such amazing rock formations. I've seen similar ones in Alberta, Canada. They make for great photographs. Nice Hub.

Nemanja Boškov from Serbia on October 20, 2011:

Hi, Belá!

Actually, I didn't vote for Miss Serbia :)

I wanted to be fair, so my vote went to Miss Antartica...

Haunty (author) from Hungary on October 20, 2011:

Thanks for stopping in and reading, L.L. Woodard.

L.L. Woodard from Oklahoma City on October 19, 2011:

I had never heard of ventifacts before reading your hub, but you've written so extensively and in an easy-to-read manner that I now feel well-informed on the topic. Nicely done.

Haunty (author) from Hungary on October 19, 2011:

OMG! Thanks, drbj! I like Miss Norway a lot and I was afraid she might not get any votes because of that posture.

drbj and sherry from south Florida on October 19, 2011:

Miss Norway may not have the best posture, Haunty, but she won my vote with her modern, technological look. Second place is Miss Fiji - she reminds me of a Rohrschach inkblot.

Haunty (author) from Hungary on October 19, 2011:

Hi Larry! Thanks for your vote. I'm sure Miss UK appreciates it. :)

Larry Fields from Northern California on October 19, 2011:

Great hub, Haunty! Voted up and more. I'd never even heard of ventifacts before.

I voted for Miss United Kingdom. Why? Because I have a dial-up modem, and she was the first to reveal herself in her full splendor. That may reflect some shallowness on my part, but no more than in traditional beauty pageants. :-)

Haunty (author) from Hungary on October 19, 2011:

Thank you, Nemanja! I hope you voted for Miss Serbia! :)

Nemanja Boškov from Serbia on October 19, 2011:

Hi, Haunty!

I knew nothing about ventifacts before reading your hub, and know I can say that I know a lot about them - which is truly fantastic!

I really enjoyed the way you explained what these are and the vote is also a great addition to the hub...

All in all, I hope this hub gets a lot of votes up, as it really desrves them!

Haunty (author) from Hungary on October 19, 2011:

Thanks, Fellow Mumbaite!

Fellow Mumbaite from India on October 19, 2011:

I voted for Miss Antartica..I think its too good to be real. How cool to see such a beautiful shape created by winds, as you say! Loved your article..

Sondra from Neverland on October 19, 2011:

Warring giants are not real, no matter what my loony ancestors say!! But I sea what you mean ;)

Haunty (author) from Hungary on October 19, 2011:

Hi! :) I don't know who I vote yet, because every one of them is so gorgeous. I learned that everything is a ventifact that was formed by the wind. If it's the see or whatever, it's not a ventifact. Giant's Causeway is not a ventifact, because I've just read that it was created by warring giants in Ireland. Your comment is awesome. Thank you!

Sondra from Neverland on October 19, 2011:

Sorry, I was so excited to get my comment out that I called them ventRifacts!

Sondra from Neverland on October 19, 2011:

I had to vote for Miss Bolivia - even if she IS a little top-heavy! You did far better on this than I thought you would :) I hope it gets tons of visits because it's worthy of several thousand reads. I am clear across the country from any deserts so I find these rock formations fascinating. Would you say the Giant's Causeway in Northern Ireland is a ventrifact? ...

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