Wind erodes the earth’s surface in 2 ways. The first is called deflation which involves dust, sand or soil being moved or carried away by the wind and the second process is abrasion where rocky or other hard surfaces are ground down and shaped by the wind and particles carried in it. Deflation is very common in deserts and other arid areas as vegetation is sparse and there is very little moisture in the soil. Often, all of the sand and other particles are blown away leaving what is called desert pavement which is a hard surface. Almost half of desert surfaces consist of desert pavement.
Aeolian or wind transport involves 3 processes: saltation, suspension and creep. Saltation is the most common process as most particles are too big to be carried away very far by the wind so instead they are picked up and carried a short distance until they hit the ground and sometimes they rebound back into the air or dislodge other particles which may also bounce into the air. If particles are smaller, then they can be picked up by the wind and suspended and can be carried for long distances before falling back to the ground. Suspension can carry some fine particles all the way around the earth. The third process is called creep and it involves larger particles of soil which are too big to be picked up by the wind. Instead, if the wind is strong enough, it will push these particles along the earth’s surface. About 25% of all particle transport happens this way.
The Devil’s Cornfield is a large expanse near the Mesquite Sand Dunes. Deflation has removed most of the sand and soil leaving behind desert pavement except where arrowweed plants are growing. These plants have adapted by hoarding soil around their root system so that they appear to be sitting on a pedestal and they resemble piles of bundled corn. As wind-blown soil and sand is collected around the base, arrowweed shrubs grow higher. These pedestals vary in height depending on location and age of the plant. Also, the ancient lakebed on which the area is situated is subsiding which makes the plants look even taller.
To log this Earthcache, e-mail answers to the following questions to the cache owner.
Question 1: The coordinates for this earthcache will take you to an interpretive sign near the parking area beside the road.
- Describe the ground surface in the area near ground zero in terms of its consistency and particle make-up.
Question 2: How would desert pavement affect further wind erosion in the area?
Question 3: Some of the sand and other particles which have been transported by the wind from this area have been deposited in what nearby geological feature?
Question 4. Optional - feel free to post a picture of you or your GPSr near the posted coordinates. Please do not include a picture of the interpretive sign though.
Logs will be deleted if an e-mail containing the correct answers isn't sent to the cache owner. Also, please be respectful of the area when you are visiting. Thanks!! I hope you will enjoy your visit to Death Valley and also learn something in the process!
Acknowledgements:
Thanks goes out to DEVA Information, NPS for approving this earth cache!
References:
dumouchelle Follow. “Desert Landscapes Dominated by Wind.” LinkedIn SlideShare, 9 May 2012, www.slideshare.net/dumouchelle/desert-landscapes-dominated-by-wind.
“Aeolian Processes.” Wikipedia, Wikimedia Foundation, 25 Oct. 2017, en.wikipedia.org/wiki/Aeolian_processes.
“The Sahara Desert: A Geomorphological Approach.” Google Sites, sites.google.com/site/worlddeserts/.
