Carbon dioxide from the air is dissolved in rainwater making it slightly acidic. A reaction can occur when the rainwater comes into contact with minerals in the rock, causing weathering. Water can get into cracks in a rock and if it freezes the ice will expand and push the cracks apart.
What are the 4 main causes of weathering? List Four Causes of Weathering. Frost Weathering. Frost weathering occurs in the presence of water, particularly in areas where the temperature is near the freezing point of water. Thermal Stress. Thermal stress occurs when heat absorbed from the surrounding air causes a rock to expand.
Salt Wedging. Begin typing your search term above and press enter to search. Press ESC to cancel. For example, a rabbit can burrow into a crack in a rock making it bigger and eventually splitting the rock, or a plant may grow in a crack in a rock and, as its roots grow, cause the crack to widen.
Even you can be a source of weathering! Boots and shoes walking over the same patch of rock may eventually wear down the rock. Chemical weathering describes the process of chemicals in rainwater making changes to the minerals in a rock. Carbon dioxide from the air is dissolved in rainwater, making it slightly acidic.
A reaction can occur when the rainwater comes into contact with minerals in the rock, causing weathering. Physical weathering occurs when physical processes affect the rock, such as changes in temperature or when the rock is exposed to the effects of wind, rain and waves. Water can get into cracks in a rock and, if it freezes, the ice will expand and push the cracks apart. When the ice melts, more water can get into the larger crack; if it freezes again it expands and can make the crack even bigger.
Rain and waves lashing against a rock can also wear it away over long periods of time. Water expands slightly when it freezes to form ice. This is why water pipes sometimes burst in the winter. You might have seen a demonstration of this sort of thing - a jar filled to the brim with water eventually shatters after it is put into a freezer. The formation of ice can also break rocks. If water gets into a crack in a rock and then freezes , it expands and pushes the crack further apart.
When the ice melts later, water can get further into the crack. When the water freezes, it expands and makes the crack even bigger. This process of freezing and thawing can continue until the crack becomes so big that a piece of rock falls off.
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