Exam 12: Weathering and Soil

The B-horizon in soil is the zone of accumulation.

When feldspar is attacked by carbonic acid it forms _____.

The ____ describes the process in which this dominant greenhouse gas circulates among Earth systems.

______,formed as water evaporates inside small spaces in rock,helps disintegrate desert rocks.

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

The reduction of pressure on a body of rock can cause it to crack as it expands.

The single most important agent for the chemical weathering is temperature.

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

As soils mature,distinct layers called ______ appear.

The _____ horizon is the incompletely weathered parent material lying below the B-horizon.

Plants and burrowing organisms contribute to soil development by __.

Sulfuric acid is produced naturally during __.

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

Frost wedging is most effective __.

Under wet and humid tropical conditions the least soluble material is the aluminum oxide called _____.

Plants,such as roots growing in cracks,and animals compacting the soil,have little influence on mechanical weathering.

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.

Olivine weathers rapidly because its isolated silicon-oxygen tetrahedra are held together by _________ ionic bonds to iron and magnesium.

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 dark-colored soil horizon that is rich in organic material and forms just below the surface vegetation.