Weathering and It's Effects

Weathering

The mechanical and chemical processes that change objects on Earth's surface over time.

Weathering and It's Effects

Weathering also changes Earth's surface. Weathering processes break, wear, abrade, and chemically alter rocks and rock surfaces. Weathering can produce strangely shaped rocks. Over thousands of years, weathering can break into smaller and smaller pieces. These pieces, also known as sediment, are called sand, silt, and clay.

Dissolving by Acids

Acid increase the rate of chemical weathering more then rain or water does. The action do acids attracts atoms away from rocks minerals and dissolves them in acid. Normal rain is slightly acidic, around 5.6 because carbon dioxide in the air forms a weak acid when it reacts with rain. Acid forming chemicals enter the air from natural sources such as volcanoes.

Examples of Mechanical Weathering

An example of mechanical weathering is when intense temperature do a forest fire causes nearby rocks to expand and crack. One of the most effective weathering processes is ice wedging. Water enters cracks in rocks. When the temperature reaches 0 c the water freezes. Water expands as it freezes and the expansion widens the crack. Another affective mechanical weathering process is abrasion. Abrasion is the grinding away of rock by friction or impact. Plants also can cause weathering. They can cause it by crumbling rocks. Animals also can cause mechanical weathering. Animals that love in soil Crete holes in soil where water enters and causes weathering.

Chemical Weathering

Changes the materials that are part of a rocks into new materials.

Chemical Weathering

Chemical weathering can affect some rock. Both obelisks were carved in Egypt about 3,500 years ago. One was moved to New York City in the 1800s. There it has been exposed or more agents or chemical weathering.

Oxidation

Combines the element oxygen with other elements or molecules.

Oxidation

Most of the oxygen needed for oxidation. Comes from the air. The addition of oxygen to a substance produces an oxide. Iron oxide is a common oxide of Earth materials.

What Affects Weathering Rates

Similar rocks can weather at different rates. The environment in which weathering occurs helps determine the rats of weathering. Both types of weathering depend on water and temperature. Mechanical weathering occurs fast in locations that have frequent temperature changes. The type of rock being weathered also affects the rate of weathering.

Mechanical Weathering

The chemical makeup of a rock is not changed by mechanical weathering. For example, if a piece of granite undergoes mechanical weathering, the smaller pieces that result are still granite.

Water and Chemical Weathering

Water is more important then chemical weathering because most substances dissolve in water. The minerals that make up most rocks dissolve very slowly in water. Sometimes the amount that dissolves over several years is so small that is seems as though the minerals does not dissolve. For a rock, the process of dissolving happens when minerals in the rock break into smaller parts in solution.

Mechanical Weathering

When physical processes naturally break rocks into smaller pieces.

Surface Area

When something is broken into smaller pieces, the total surface area increases. Surface area is the amount of space on trout side of an object. The weight of weathering depends on the rocks surface area that is exposed to the environment.