Question 16.13

In northern Illinois, you can find two soils developed on the same kind of bedrock: one is 10,000 years old and the other is 40,000 years old. What differences would you expect to find in their compositions or profiles?

Question 16.14

Which igneous rock would you expect to weather faster, a granite or a basalt? What factors influenced your answer?

Question 16.15

Assume that a granite with grains about 4 mm across and a rectangular system of joints spaced about 0.5 to 1 m apart is weathering at Earth’s surface. What size would you ordinarily expect the largest weathered particle to be?

Question 16.16

Why do you think a road built of concrete, an artificial rock, tends to crack and develop a rough, uneven surface in a cold, wet region even when it is not subjected to heavy traffic?

Question 16.17

Pyrite is a mineral in which ferrous iron is combined with sulfide ions. What major chemical process weathers pyrite?

Question 16.18

Rank the following rocks in the order of the rapidity with which they would weather in a warm, humid climate: a sandstone made of pure quartz, a limestone made of pure calcite, a granite, an evaporite deposit of halite.

Question 16.19

What would a planet look like if there were no weathering at its surface?

Question 16.20

Would a prolonged drought affect the potential for landslides? How?

Question 16.21

What geologic conditions might you want to investigate before you bought a house at the base of a steep hill of bedrock covered by a thick layer of soil?

Question 16.22

What evidence would you look for to indicate that a mountainous area had undergone a great many prehistoric landslides?

Question 16.23

What factors would make the potential for mass movements in a mountainous terrain in the humid tropics greater or less than the potential in a similar terrain in a desert?

Question 16.24

What kind(s) of mass movements would you expect on a steep hillside with a thick layer of soil overlying unconsolidated sands and muds after a prolonged period of heavy rain?

Question 16.25

What factors weaken rock and enable gravity to start a mass movement?