Exam 5: Weathering and Soil

As a geologist employed by an engineering firm, your first assignment is to assess the potential for soil erosion on a 2000-acre site.There has been no previous development on the property, which consists of roughly equal portions of farmland, forests that have recently been cut down, and hilly terrain with native vegetation.Briefly outline which areas have a higher potential for erosion problems, and what steps you might suggest to prevent or lessen soil erosion.

Which term denotes the true soil above the zone of partly weathered bedrock?

Which of the following statements concerning humus is false?

What kind of weathering involves only a reduction in the sizes of bedrock, regolith, and mineral particles by external physical forces?

Which one of the following is an important, mechanical weathering process for enlarging fractures and extending them deeper into large boulders and bedrock?

As ________ increases the surface area of a rock or mineral, this allows ________ to occur at a faster rate.

Write a balanced chemical reaction for the acid weathering of calcite or limestone.

Minerals which undergo oxidation must lose electrons during this process.

The B soil horizon is called the zone of leaching.

How do large, spheroidal boulders form from massive bedrock?

The material caliche represents an extensive, concrete-like accumulation of calcite in the B horizon of a pedocal soil.

Compare and contrast soil formation between an arid region underlain by quartz sandstone and a temperate climate in an area composed of granite.

Which of the following best describes the process of eluviation?

Preferential disintegration and decomposition at the corners and edges of blocks of rock describe what form of weathering?

Clay minerals formed from gabbro or diorite bedrock illustrate which kind of weathering?

Quartz weathers readily to aluminum-rich clay minerals.

Which are examples of Earth's external processes?

Weathering only acts on naturally occurring rocks and minerals, not on man made substances like concrete, glass, metal, or plastic.

Which of the following best describes the A soil horizon?

Sheeting parallel to quarry floors, and rock bursts on fresh cuts and tunnels, are caused by unloading.