GEO 102 Final Chapter 11

Physical weathering is greatest under conditions of

Temperatures that reach below freezing.

When rock is broken and disintegrated without dissolving, the process in operation is

Physical weathering.

Uplift of the landscape creates____ energy which is converted to_____ energy when materials begin to move downslope.

Potential; kinetic.

The dramatic domes and arch-shaped features found in granitic mountain masses result from

Pressure-releasing jointing, exfoliation, and sheeting.

Which type of weathering is limited to arid environments?

Salt-crystal growth.

A persistent mass movement of surface soil is called a

Soil creep.

The weathering of limestone can create circular depressions known as

Sinkholes.

One side of a sand dune is typically steeper than the other side. The slope of the steepest is controlled by the angle of repose for sand-- which has a value that is typical for most materials. This angle is about_____.

34 degrees.

The dynamic equilibrium model refers to

A balancing act between tectonic uplift and rates of reduction in a given landscape.

Movement at the geomorphic threshold signals

A conversion of potential energy to kinetic energy.

Landslides occur when

A threshold is reached. The internal friction is overcome by the force of gravity. When driving forces exceed resisting forces.

After a threshold is crossed, the landscape

Adjusts to a new equilibrium condition.

If you have ever played on a beach and made a sand castle, you used wet sand rather than dry sand. You did this because the____ of wet sand is greater than that of dry sand.

Angle of repose and cohesiveness.

The steepness of a slope of loose material at rest is the

Angle of repose.

Karst topography is formed primarily by

Carbonic acid solution.

Which of the following countries is noted for its spectacular tower karst?

China.

In 1973, part of the flat ground on which a subdivision was located became saturated and began to flow toward the Saint Lawrence River at speeds of up to 26 km/h (16 mph). The ground that flowed consisted of silts and clays-- not large, rocky and regolith. What type of mass wasting event was this?

Earth flow.

If material is to move downslope, it must overcome the force of

Friction, the cohesion of particles to each other, inertial resistance of the material.

The fact that water expands as much as 9% of its volume as it freezes is the basis of

Frost wedging.

The science that specifically studies the origin, evolution, form, and spatial distribution of landforms is

Geomorphology.

Chemical weathering is greatest under conditions of

Higher mean annual rainfall and temperatures.

In which of the following climates would the subsurface line of contact between weathered and unweathered materials be at the greatest depth?

Hot and wet.

Which of the following is a type of chemical weathering process?

Hydrolysis.

Which of the following can initiate hillslope failure?

Making a road cut in the side of a hill, increasing the slope angle, excessively watering a slope.

All unit movement of materials propelled and controlled by gravity are referred to as

Mass movements or mass wasting.

A translational slide involves

Movement of surface material along a planar surface.

In the Northern hemisphere mid-latitudes, slopes that face_____ have more trees on them because____.

North; they are more moist.

Exfoilation occurs because

Overlying rock is removed, thereby allowing the underlying rock mass to expand.

The yellow-red stains that occur on some rock surfaces are the result of____ which is a form of___ weathering.

Oxidation;chemical.

Hydrolysis involves

Water chemically combining with minerals.

Which of the following are the principal active agents involved in chemical weathering?

Water, oxygen, carbon dioxide.

Other than the rock itself the most important chemical substance needed for the majority of weathering processes it

Water.

The disintegration and dissolving of surface and subsurface rock is called

Weathering.

The rate at which rocks weather depends upon

The climate of an area, the type of rock, the amount of vegetation in the area.

In the Andes Mountains of South America, entire towns of thousands of people have been buried suddenly when snow fell from high on a mountain side, melted on impact, and then mixed with loose materials that traveled downhill as a viscous fluid. This type of catastrophic event is known as

Debris avalanche.