In this Earth Cache lesson we are going to continue to learn about Limestone and errosion.
If you have been working on the Earth Caches on these trails you may have learned what Limestone is, how it's made, properties, and what uses there are for limestone. On this Earth Cache Adventure we are going to learn about the effects of erosion on limestone over a couple of years, like a couple million of years to say the least.
Much of my Source Material is found from the Arkansas Geological Survey group, and you can get much more in depth information that what I am going to cover today. Take your time to check it out!
Water's Physical Properties
Being able to exist in all three physical states on the earth surface makes water a one of a kind substance that is liquid, solid (ice), at 32 F and gas (steam) at 212 F. Water is unique in that it is one of the very few substances that when it becomes a solid it becomes less dense and will float on its liquid form. Water can store a lot of heat energy because it has a high specific heat index. This allows large bodies of water to help cool or heat the earth’s atmosphere therefore keeping our climate’s temperature more constant. Because water has mass or weight (8.33 pounds per gallon), that when it is in motion it can move with great force as in the current of a river or as waves in the ocean. Such forces shape the land on the earth’s surface. That shaping, or erosion is what we want to talk about, and at this location, you will get a true hands on feel of what erosion does to limestone.
No moss, not No Mas.
In the context of stream hydrology, sediment is inorganic and organic material that is transported by, suspended in, or deposited by streams. Sediment load, which is the quantity of sediment transported by a stream, is a function of stream discharge, soil and land-cover features, weather conditions, land-use activities, and many other factors. Sediment load carried by streams and rivers can be composed either of fine materials, mostly silts and clays, or larger materials such as sand.
Solid sediment load can be divided into two components on the basis of the mode of sediment transport: suspended sediment, and bedload sediment, each of which is produced by mechanical weathering processes, is clearly visible, and is able to settle out of water. Suspended sediment consists of silt-sized and clay-sized particles held in suspension by turbulence in flowing water. Bedload sediment consists of larger particles which slide, roll, or bounce along the stream-bed by the force of moving water. Dissolved load consists of inconspicuous material in solution moving downstream. It is produced by chemical weathering processes, and does not settle out of water.
Sediment yield is the total quantity of sediment transported from a watershed (drainage basin) at a given location in a given period of time. Low suspended sediment yields can be attributed to, among other factors, a region's low erosion rate. Permeable soils and low topographic relief, in general, help limit the availability of eroded material from within a watershed. Conversely, relatively impermeable soils and steep topography can yield high erosion rates and therefore greater sediment yield.
So what does that mean, what am I really trying to tell you? Well in simple terms, water and sediment will pollish the lime stone, some pitting may occur as larger debris "scrub" the limestone, but what you will get from this process is water carved limestone, beautiful and natural. As the water decreases you find yourself a perfect place to sit and contemplate the finer things in life...
Did you know?
Each kind of sedimentary rock turns into a different kind of metamorphic rock - limestone turns into travertine or marble, and shale turns into slate, and sandstone turns into quartzite. Even though slate is a metamorphic rock, it still looks a lot like a sedimentary rock - it is still in thin layers.
Now that we learned a little bit about erosion and the effects it has on limestone, take a moment to study ground zero. With the information above, and information at GZ you should be able to answer the following questions. You have 24 hours to send me an email (found in my geocaching profile) with the correct answers. Failure to do so will result in the removal of your "Found it log". Please add the GC code and title in the subject line. If you are sending answers for multiple people in your group, please add all the names in your email to ensure they don't have their log deleted :) Photos with you or the group you are with of the area would be greatly appreciated.
Requirements: (please do not put your answers in the log)
1 Standing at Ground Zero what kind of lime stone do you see?
2 What Process of erosion is going on under your feet?
3 Explain what has happend to the limestone at this stream.
4 How long is the Limestone here?
5 What phiscal property of water is present at GZ?
Additional Sources: