Jean Dry Lake: Its All Coppice-setic EarthCache
Hidden : 3/11/2008
Difficulty:
2.5 out of 5
Terrain:
2 out of 5

Size: Size: other (other)

Join now to view geocache location details. It's free!

Watch

How Geocaching Works
Looking for a different adventure?

Please note Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

Geocache Description:


The easiest access to this Earthcache is off of the old Los Angeles Highway by way of the paved road at N 35 49.671, W 115 17.024. Follow your GPS receiver from here. For this Earthcache, you will be comparing the sizes of coppice dunes both on and just off of the surface of Jean Dry Lake. Bring a ruler or tape measure in order to collect your measurements.

Jean Dry Lake is a playa lakebed located just east of Jean. Playa lakebeds are common in the Mojave Desert. They form in the flat basin areas between mountain ranges where there is no outflow of water. These areas were previously valleys which may be filled with hundreds of feet of sediments from the surrounding mountains. Only the fine sediments such as sand, silt, or clay, reach the center of the playa lakebed. Other materials, such as gravels, cobbles, and boulders, tend to separate out before reaching the lakebed.

A type of small sand dune has begun forming at the base of the saltbushes (Atriplex sp.) due to aeolian, or wind blown material from the playa. Coppice dunes are commonly scattered throughout arid regions where shrubs and blowing silts and sands are abundant. The size and shape of a coppice dune depends on the amount of material available, the characteristics of the wind, the properties of the canopy, and age of the accumulation of the material.

As the mound of the coppice dune and the saltbush grows larger, the number of microhabitats increases, allowing an increased diversity of plants and animals to utilize this space. Only certain kinds of plants are associated with a coppice dune, since only those species that can form new roots and shoots from buried branches can continue to grow as the material accumulates around them. If material accumulates faster than the plant can grow, the plant will die, and the dune will be blown away by the wind.

Because the silt and sand accumulates in piles around the plants and is swept from the surfaces between, a rough topography develops that is very different from the smooth and flat surface of the playa, which is devoid of vegetation.

To receive credit for this Earthcache:

1.) Measure the height of 5 of the coppice dunes located at the given coordinates.

2.) Walk north to N 35 47.838, W 115 15.000 and measure the height of 5 of the coppice dunes here.

3.) Send me a note with the average height of the coppice dunes at each site, also letting me know which site has the taller dunes. Include an explanation as to why there might be a difference in height for the two locations.

Please consider posting photos of yourself, or the local geology, when you log this EarthCache. Photos can be an additional rewarding part of your journey, but posting them is not a requirement for logging this EarthCache, and is strictly optional.

The above information was compiled from the following sources:

Desert Process Working Group. Summary: Dunes. Online at: (visit link)

Digital Desert – Playas. Online at: (visit link)

Tingley, J.V. et al. Geologic Tours in the Las Vegas Area. Nevada Bureau of Mines and Geology Special Publication 16.

Additional Hints (No hints available.)



Attributes

No attributes available

Advertising with Us

Inventory

There are no Trackables in this cache.

View past Trackables

What are Trackable Items?

Bookmark Lists

View all 7 bookmark lists...