A marble statue is left exposed to the weather. Within a few years, the details on the statue have begun to weather away. This weathering probably is caused by

Granite lasts a long time when it is used for building in areas where

The most important factors in determining the rate of weathering are

When earthworms add their wastes to the soil, then die and decay in the soil, they are contributing to the formation of

Most of the work of mixing humus within the soil is done by

Plowing removed the grass from the Great Plains and exposed soil. What effect did this have when a drought struck the Great Plains during the 1930's?

What kind of weathering causes the mineral composition of rocks to change?

Frost wedging causes mechanical weathering of rock by means of

The agent of mechanical weathering in which rock is worn away by the action of other rock particles is called

A hot and wet climate causes weathering to take place

A permeable rock weathers easily because it

Soil formation begins with the weathering of

Soil that is rich in humus has high

In which soil layer would you find loam that is rich in humus?

The texture, or particle size, of soil determines

Living organisms in soil help to

What term describes the management of soil to prevent its destruction?

The practice of plowing field along the curves of a slope is called

In conservation plowing, why are dead weeds and stalks of the previous year's crop left in the ground?

After chemical weathering, the chemical makeup of the weathered rock is ______________ that of the original rock.

The movement of rock particles by ice, wind, water, or gravity is called

The rate of chemical weathering is __________ in hot, wet climates than in cold, dry climates.

______________ are tiny worms that live in soil.

To restore soil's fertility, a farmer might plant legumes as part of a soil conservation technique called

Water and wind can _________________ soil, or carry it away.

Two factors that determine the rate of weathering are the type of rock and the __________________.

Sandy topsoil is said to be ______________ because water drains quickly through the spaces between the sand particles.

Rapid chemical weathering can be caused by _______________, which is rain combined with pollutants.

One agent of chemical weathering is ___________________, which combines with water to form carbonic acid.

A rock that contains tiny, connected spaces through which water can move is said to be ________________________.

You would probably find the most decomposers in the soil layer called the _____________________.

Humus makes soil _____________, or rich in nutrients that plants need to grow.

Bacteria and fungi in soil are called __________________ because they break down dead plants and animals.

In the 1930's, an area in the southern Plains states was named the ________________ because the topsoil turned to dust.

Which layer of soil in the diagram would you find humus? What is this soil called?

Which layer of soil is made up only of partly weathered rock? What is this layer called?

Which layer in the diagram provides one of the main ingredients in soil? What is it made of?

Which layer of soil in the diagram contains clay and other particles of rock, but little humus? What is this layer called?

The top three layers in the diagram are the three soil horizons. Which of the soil horizons forms last?