Note: As of Feburary 2021
To commeorate the Mars 2020 rover, Perserverance, I am altering the name of this earthcache. Originally called "I Can't Stand it Anymore", this earthcache will focus on how sand and wind can create ripples, a common geomorphological feature on the surface of Mars. Below is an black and white image taken from NASA's Opportunity rover in August of 2010. Note the sand ripples on Mars and how they compare to GZ.
Some geology of Mars info:
Note that on Mars, gravity is much less (about 38% less) so it is easier to move larger grains of further distances. However, the atmosphere is less than 1% as thick as Earth's, so there is not much force that can drive large sand dunes on Mars. Also, the chemical makeup of thes grains are mostly basaltic (an igneous rock) which contains plenty of olivine hence why it appears so dark. At GZ, you will note that the sand is mostly all white.
As you approach the Basin Road exit, you may notice that there is a lot of sand. And where you would look over the horizon and see rocks are no longer there. To understand why and how these sand formations are created, you must learn how this sand came to be.
Most rocks on earth are made of quartz (SiO2) in some shape or form. Quartz is a hard substance that has lasted millions of years on earth. Because quartz is abundant on earth, you can find it almost anywhere. Sandstone is a perfect type of rock that quartz is in. Sandstones form when large bodies of stagnate water has lots and lots of granite sand grains. These granite particles become eroded from mountains by wind, rain, and snow. Granite is the most abundant rock on earth's crust and it's one of the reasons why there is a lot of sandstone on earth too.
Eventually, these sand particles settle at the bottom of a lake or ocean and accumulate on top of each other to build different distinct layers. The layers near the surface are younger than the layers near the bottom. This is due to the fact that the layers on the bottom had to be there first so that the layers above could settle on top of them. Over time, these particles are squeezed as more and more layers of sediment compile on top of them. So much so, that they fuse into a rock. It's kinda like microscopic velcro. The further you are away from the shore, the more calm the water is and the likely hood of finer sediment settling out greatness. When two particles of granite make contact under pressure, they are fused together. This new rock is called sandstone, and it's a sedimentary rock meaning it was created from other sediments.
Over millions of years, the body of water dried leaving behind the lake bottom full of silt. After more time have past, natural weathering of the finer silt erodes it away to rivers and streams until you reach the sandstone underneath. Sometimes it forms in beautiful layers and colors such as that in Utah and Arizona. Because sandstone is harder than the silt, it takes more time for it to erode under normal circumstances, but given enough time it does erode away.
Because this is a basin, hence Basin Road, when things erode, they end up here. During rainy seasons, this basin can fill up to become a seasonal lake. When it dries, the sand particles are left behind. During warmer months, the heat and wind make the sand extremely dry and cracked, hence the reason why it's so fine unlike many beaches along the coast. In order for the sand you see here to form, it must have been eroded at least twice. Once when it was originally granite rock and one again to break up the sandstone into sand.
Works Cited
https://www.tes.com/lessons/IS414CIMny7rcQ/weathering-erosion-and-deposition
http://thebritishgeographer.weebly.com/river-processes.html
http://blaineharrington.photoshelter.com/image/I0000ncY3M74tKio
http://www.imgmob.net/desert-sand.html
TO LOG A FIND ON THIS CACHE YOU MUST GIVE ME THE CORECT ANSWERS BEFORE YOU LOG A FIND. YOU CAN CONTACT ME THROUGH MY EMAIL OR THE GEOCACHING MESSAGE CENTER. ANY INCORRECT ANSWERS WILL RESULT IN A DELETED LOG
1. "Planetary Geology on Earth: Martian Sand" on the first line of your email.
2. Describe the sand's (a) texture, (b) color, (c) and size of the particles in relationship other types of sand you've seen before.
3. Do you think the sand here is being diminished or replenished more often here? Explain.
4. Draw an imaginary 1 meter (3 ft) by 1 meter (3 ft) box around undisturbed sand. Count the number of ripples you see and the average hight of them. Also, tell me the average distance in-between ripples.
5. Based on your observations, what compass direction is the sand moving? (N, W, S, E, NW, SW, SE, NE)
* NOTE - You will likely not receive an email back from me, unless I need clarification on your answers. Please, don't wait for me to tell you you have it correct or not. I do review your emails within 12 hours of getting them in my inbox and with other of my earthcaches, it has become too hard to do. As soon as you send the email, you can log this earthcache.