weathering by ryan

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Weathering : 

Weathering Weathering is the breakdown of rock “in situ” (where it is) Erosion involves taking away and further breaking down rock as it moves. There are four main agents of erosion Rivers (fluvial), Sea (waves), Glaciers, Wind Task: Use this presentation as a base to add your own text and diagrams when asked for. When you have finished upload it to a share site such as slideshare or authorstream, get the embed code and place it in your eportfolio.

Types of Weathering : 

Types of Weathering Physical Chemical Biotic Freeze-Thaw Exfoliation (onion-skin) Carbonation oxidation Plant roots Animals burrowing

Freeze-Thaw : 

Freeze-Thaw Other images Explanation: Freeze-Thaw describes what happens when in colder climates water seeps into the cracks inside the rocks and freezes when the temperature goes down at night expanding the cracks in the rock. Then, in the morning, the water thaws and the rock divides into several pieces.

Exfoliation (Onion skin) : 

Exfoliation (Onion skin) Description and Explanation: In places like the desert where temperature changes radically from day time to night time, the heat of the day expands the outer layers of the rock and the rapid cooling of the night time pulls the layers back in giving it an onion skin like look to it.

Biological : 

Biological Bonus points if you actually take one of the photos that you insert on this page This is when the roots of plants break up rocks as they grow. Burrowing animals can also break up the soil and rocks. Snails also have an effect. Just look at the trails they leave on walls. The main impact is that by aerating the soil they allow other agents to directly weather the parent rock which is under the soil. The breakdown of dead plants also releases an acid called humic acid and this is important in the breakdown of rock. This occurs especially in hot humid tropical areas, however it is normally associated with Chemical Weathering.

Chemical : 

Chemical 1. Oxidation is when oxygen in the air reacts with chemicals in the rock. The most important is when iron in rocks in one form called ferrous oxide (FeO) combines with oxygen to form the soluble Ferric oxide (Fe2o3). This is basically rust and leads to red soils. This happens a lot in tropical areas also. Once again. .. Look for rocks with red streaks in them or even soils and this will show evidence of oxidation. Original photos will get you bonus points

Carbonation – Limestone areas : 

Carbonation – Limestone areas Describe and explain the situation here: When it rains, carbon dioxide (CO2) and water (H2O) mix to make small amounts of carbonic acid (H2CO3)). Limestone is very vulnerable to carbonic acid because limestone consists mainly of calcium carbonate (CaCO3) which reacts with carbonic acid to make calcium bicarbonate (Ca(HCO3)2) which is a gas at room temperature. So all in all, rain dissolves limestone.

Climate and Weathering : 

Climate and Weathering Research the average annual temperature and precipitation of Barbados. Note what it is here and describe what type of weathering occurs here.

Next : 

Next We will be looking at the limestone landscape of Barbados and comparing it to other limestone landscapes worldwide. What is the role of limestone in shaping some of the features we have Caves, underground streams, gulleys, Humans and the limestone environment

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