Chap.12 Sec.4 Mass Wasting

What is mass wasting?

• Weathering by wind

• Movement of material downhill due to gravity

• Transport of sediment by rivers

• Formation of new rock

Answer explanation

Mass wasting refers to the movement of material downhill due to gravity. This process includes landslides and rockfalls, distinguishing it from other options like weathering or sediment transport.

Another term often used for mass wasting is:

• deposition

• landslide

• erosion

• weathering

Answer explanation

Mass wasting refers to the movement of soil and rock down a slope due to gravity. The term 'landslide' specifically describes this process, making it the correct answer. Other options like erosion and weathering refer to different geological processes.

Which is the most rapid type of mass wasting?

• Creep

• Slump

• Rockfall

• Soil flow

Answer explanation

Rockfall is the most rapid type of mass wasting, characterized by the sudden and fast movement of rock down a slope, unlike creep, slump, and soil flow, which occur more slowly.

During a flow, material moves like a:

• solid block

• gas

• liquid

• crystal

Answer explanation

During a flow, material behaves like a liquid, allowing it to take the shape of its container and flow easily. Unlike solids, gases, or crystals, liquids can move and adapt their form, making 'liquid' the correct choice.

A mixture of water and sediment that flows like a liquid is called a:

• load

• slurry

• deposit

• layer

Answer explanation

A mixture of water and sediment that flows like a liquid is specifically referred to as a 'slurry'. This term accurately describes the fluid nature of the mixture, distinguishing it from other options like 'load' or 'deposit'.

A fast-moving flow of mud and debris is called a:

• slump

• creep

• mudflow

• rockfall

Answer explanation

A fast-moving flow of mud and debris is specifically termed a 'mudflow.' Unlike a slump or creep, which are slower movements, a mudflow is characterized by its rapid and fluid nature.

A slide involves movement of a:

• liquid

• loose particles

• solid block of material

• dissolved ions

Answer explanation

A slide typically refers to the movement of a solid block of material, as it involves the sliding motion of a cohesive mass rather than liquids, loose particles, or dissolved ions.

Slides typically move along a:

• curved surface

• fracture plane

• river channel

• valley floor

Answer explanation

Slides typically move along a fracture plane, which is a surface where the rock has broken and allows for movement. This is the correct choice, as other options do not accurately describe the mechanism of slide movement.

A rockfall occurs when:

• sediment dissolves

• rock falls freely through the air

• soil flows slowly

• water freezes

Answer explanation

A rockfall specifically refers to the event when rocks detach from a slope and fall freely through the air due to gravity. This distinguishes it from other processes like sediment dissolution or soil flow.

Rockfall usually occurs on:

• flat plains

• gentle slopes

• steep cliffs

• riverbeds

Answer explanation

Rockfall typically occurs on steep cliffs due to the gravitational pull on loose rocks and debris. The steep angle allows for easier detachment and movement of materials, making this the most likely location for rockfalls.