the 'falls' limestone & shale rock Protrusions EC* EarthCache
the 'falls' limestone & shale rock Protrusions EC*
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Difficulty:
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Terrain:
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Size: 
(other)
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As an EarthCache, there is no container to discover. Rather, with this cache, you discover something interesting about the geology of this area. To receive credit for this 'find' please e-mail to my profile the answers to the following questions. IT SURE MAKES IT EASIER IF YOU SEND THE ANSWERS SOON AFTER YOU LOG SO THAT I CAN ID THEM WITH YOUR FIND otherwise I may delete.
*DO NOT leave the trail until U reach this earthcache!
REQUIREMENYS:
1- Determine wheather the 'weathering' that you are seeing is PRIMARLY mechanical or chemical weathering.
2- List the TYPES of mechanical and chemical weathering that you observe.
3- At the middle of the falls,(at the bottom of the falls) do you see an example of severe 'weathering' of the limestone or of the shale?
4- Submit a pic and/or submit the estimated length of the falls as well as its height.
FTF: Honors to City Slicker OH & Folboter JAF
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The Sharon Woods Park is very cache friendly. There are now three Earthcaches, a Virtual as well as a few traditional & multi caches.
This earthcache relates to the rock protrusion to your LEFT as you stand on the overlook platform above 'the falls'. NOTICE THE ROCKS AT THE EDGE OF THE FALLS.
In this earthcache, you are looking at the limestone (dark rock) and shale (light gray) rocks, trying to determine the reasons for the 'weathering' that is taking place on this formation.
Weathering is the decomposition of the earth's rocks, soils and minerals through direct contact with the atmosphere. Weathering occurs without movement, meaning that erosion is NOT considered to be weathering, though it may have caused the environment for weathering.
There are TWO TYPES of weathering - MECHANICAL {PHYSICAL) and CHEMICAL.
MECHANICAL weathering - involves the breakdown of rocks and soils through direct contact with atmospheric conditions such as water, ice and preasure. Mechanical weathering is a major cause of the disintergration of rocks.The rock size is broken down into smaller particles but the rock components are not altered.
CHEMICAL weathering - involves the direct effect of atmospheric chemicals or biologically produced chemicals in the breakdown of rocks, soils and minerals. The composition of the rock components DOES change in chemical weathering.
The minerals left over after the rocks breakdown combined with organic materials creates soil. The mineral content of the soil is determined by its parent sources. Thus, a soil derived from a single rock type can often be deficient in one or more minerals for good fertility, while a soil weathered from a mix of rock types often makes a more fertile soil.
TYPES OF MECHANICAL WEATHERING:
THERMAL EXPANSION - This type of mechanical weathering happens when there is a great CHANGE in temperature on a cyclic basis. The stress of the temperature change causes the peeling off of the layers of rock into sheets. Thermal expansion is increased by moisture.
FROST DISINTERGRATION - This happens in environments with alot of moisture and where the temperature often fluctuates above and below freezing. When the water freezes it crystalizes and expands, producing stress on the rock. Limestone and shale are especially vulnerable to this type of weathering.
BIOLOGICAL WEATHERING - Living organisms may contribute to mechanical as well as chemical weathering. The attachment of organisms to the rock surface enhances physical as well as chemical breakdown of the surface microlayers. On a larger scale, seedlings sprouting in a crevice and plant roots exert physical preasure as well as providing for watger and chemical infiltration.
TYPES OF CHEMICAL WEATHERING:
DISSILUTION - Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. It is the cause of acid rain, and the acicicness is 2-3X the normal.
CARBONATION - This takes place when rain combines with carbon dioxide. It has an effect especially on limestone because the weak carbonic acid formed reacts with calcium carbonate.
BIOLOGICAL-CHEMICAL WEATHERIING - A number of plants and animal may create biological/chemical weathering. The decaying remains of plants and the waste of animals form organic acids which when disolved in water causes chemical weathering.
Great USA weather temp/map: (visit link)
PERMIT #140331-01
Additional Hints
(No hints available.)