Exam 5: Weathering and Soil

When feldspar is attacked by carbonic acid it forms clay minerals.

The term mechanical weathering refers to changes in a rock that are physical; there is little or no chemical change.

Of the many processes that cause rocks to disintegrate, the most effective are ____.

_______ are commonly left after complete chemical weathering.

Sulfuric acid is produced naturally during __.

Transportation is the picking up or physical removal of rock particles by an agent such as running water or glaciers.

_______ refers to the group of destructive processes that change the physical and chemical character of rocks at the Earth's surface.

The most important natural source for the formation of acid for rock weathering at the Earth's surface is dissolved _______.

When feldspar is attacked by carbonic acid it forms _____.

Because of the slow pace of weathering processes, it takes millions of years for a viable soil profile capable of supporting plant life to develop in most areas.

Hydrogen ions given off by natural acids can disrupt the crystal structure of most minerals, making the structure susceptible to further decomposition.

As soils mature, distinct layers called ______ appear.

In arid climates, soils are thin and soil water tends to move ______

Plants and burrowing organisms contribute to soil development by __.

Without chemical weathering, the elevated levels of carbon dioxide in the atmosphere would have long ago made the Earth too hot to sustain life.

The _______ horizon is the uppermost layer of a soil; it consists of organic material.

Ordinary rain has a pH of about 5.5 to 6 from the carbon dioxide in the atmosphere and from natural sources of acidic sulfur gases.

___ are the most common materials precipitated as cement, which binds loose particles of sand into a solid sedimentary rock.

Frost wedging is most effective __.

A ___ soil is one that develops from the bedrock directly beneath it.