Question

Match each description with the pictures shown above.

Answer 1

Answer:

Sediment A:

1. Carbonate sand
2. Sediment made of seashell and calcite
3. Sediment that has travelled farther

Sediment B:

1. Quartz sand
2. Made of harder minerals
3. Forms when rocks break apart

Explanation:

Sediment A: In the figure shown on left, the particle size is small and corners are round. This suggests that it is most likely made up of carbonate which can dissolve easily in the presence of water and CO2 forming weak acid (carbonic acid). Likewise, it is also possible that the material has traveled longer distances and due to erosion, the corners of the particle has become rounded. The carbonaceous material in the sea environment is often made by carbonate producer organisms that use calcite to make the protective shell.

Sediment A: In the figure shown on right, the material is bigger in size with hard and sharp corners. This means that it is either broken recently from the rock and has not traveled longer distances OR, it is made up of harder minerals that cannot break easily by weathering and erosion process. Quartz sand has such properties.