Q2. Answer the following questions:
a) How does biological weathering take place?
b) Name two factors responsible for mechanical weathering.
c) How does composition of rock affect mechanical weathering?
d) What is carbonation? Give two examples of landforms formed by carbonation.
Answers
Answer:
a) Biological weathering occurs when plants break up rocks with roots or root exudates. ... Biological weathering increases with soil thickness until optima for biotic activity are reached, but decreases when soils get thicker and biotic activity has less influence on weathering.
b) Exfoliation or Unloading. As upper rock portions erode, underlying rocks expand. ...
Thermal Expansion. Repeated heating and cooling of some rock types can cause rocks to stress and break, resulting in weathering and erosion
c) Another factor that affects the rate of weathering is the composition of rock. ... The presence of iron in rocks causes them to weather more quickly and break apart more easily. Some minerals are softer than others, and therefore rocks that contain these minerals will weather more rapidly.
d) It acts on a rock containing limestone and chalk. The reaction results in calcium bicarbonate which is highly soluble and gets easily washed away in solution as it flows through rocks or seeps below the surface. Weathering of limestone region in this way give rise to various landforms