The Kelso Dunes

1. The Kelso Dunes By: Sam Bova

2. Kelso Dunes • Largest dune field of eolian sand deposits in the Mojave Desert (45 square miles) • The dunes reach heights of up to 650ft. • Third Largest Dune Field in the U.S. Star Dune (highest dune)

3. Location • The Kelso dune field is located in the Mojave National Preserve in California. • Southeast of Soda Lake and flanked by the Granite Mountains to the south and the Providence Mountains to the east.

4. Yea Sand! • The Kelso dune fields consists of: 1. SandDunes -(actively forming and migrating/plant-stabilized) 2. Sand sheets - flat areas between the dunes themselves and the source of sand 3. Sand Ramps - piles of sand along the sides of mountains

5. Formation of Dune Fields • Requirements: 1. Large amount of sand. 2. Wind strong enough to move sand. 3. A good location for it to accumulate. • Once the sand accumulates into piles the wind blows more sand onto the pile until it collapses. The sand stops collapsing when it has reached its “angle of repose”.

6. The Mystery of the Missing Sand… • No new sand blows into the area to replenish and allow the dunes to grow. • Where did the sand come from? • The mineral composition and morphology demonstrate that the sand traveled from the Mojave river sink near Afton canyon. • The Providence and Granite Mountains then blocked the blowing sand and it piled up forming the Kelso dune field.

7. Dune Composition • Sources of Sediment:1. Lake Beds2. Alluvial Fans3. Ephemeral washes (Mojave River bed) • Composed primarily of: -light-colored quartz -light-colored feldspar -small amount of magnetite and amphibole at dune crests

8. Magnetite Mining • Kelso Dunes used to be under the Bureau of Land Management. • Magnetite mining operations took place in the Kelso Dune Field.

9. Kelso Dune Formation: • The Dunes formed 25,000 years ago. • They are actually 5 different sets of dunes stacked on top of one another. • Each set represent a dry climate period.

10. A Paleoclimatic Record • Due to their dependence upon climate, dunes can be studied to determine past climate patterns. • Wet periods: dune growth slows. -Plants stabilize the dunes and surrounding sediment. -Lakes trap sediment beneath the water. • Dry Periods: dune growth increases -Plants die creating loose sediment. -Lakes dry up exposing large areas of sediment. • Lots of dune growth when Soda and Silver Lakes dried up. • Dune erosion in the Quaternary when Lake Mojave’s water levels were high.

11. Evaporite Crust of Soda Lake • Mojave River • Dune With Vegetaion

12. Singing Sand and Booming Dunes • As wind passes over the dunes a low frequency rumble is emitted from the dunes. • How it works: 1. The sand grains collide emitting surface elastic waves causing the grains to move in one motion.2. The vibrations of the sand particles create the sound. • In order to produce the sound there must be a thick layer of dry sand on the surface of the dune. The sound waves bounce back and forth between the dry surface layer and the moist sand below. • Therefore, the drier the dunes the louder the noise. • http://www.youtube.com/watch?v=Sw2V0CHgQV8

13. Dune Life • Kelso Dunes Giant Sand Treader • Kelso Dunes Jerusalem Cricket • Giant Mydid Fly • Kelso Dunes Shieldback Katydid • Fringe-toed Lizard -known for its ability to “swim” through the sand

14. Thanks! YouTube - Kelso Dunes