CLARB Soils and Geology 3

Question 1

Which publicly available resource provides detailed soil survey data, including soil limitations and suitability ratings, for landscape site analysis?

Accepted Answer

USDA Web Soil Survey (WSS)

Answer

The USDA Web Soil Survey (websoilsurvey.sc.egov.usda.gov) provides county-level soil maps, taxonomic data, and interpretive ratings for construction, planting, and drainage suitability.

Question 2

Karst topography — characterized by sinkholes, caves, and internal drainage — develops primarily in areas underlain by which rock type?

Accepted Answer

Soluble carbonate rocks such as limestone and dolomite

Answer

Karst landscapes form when slightly acidic groundwater dissolves soluble carbonate rocks (limestone, dolomite), creating caves, springs, and sinkholes over time.

Question 3

Hydric soils serve as a primary indicator for identifying which regulated landscape feature during site analysis?

Accepted Answer

Jurisdictional wetlands

Answer

Hydric soils formed under prolonged waterlogged conditions exhibit mottling, gleying, and low chroma colors that indicate wetland conditions, and are one of the three required criteria for jurisdictional wetland delineation.

Question 4

What geological term describes fine-grained sediment deposited by flowing water in river floodplains and deltas?

Accepted Answer

Alluvium

Answer

Alluvium is sediment deposited by flowing water; alluvial soils are typically fertile and well-sorted, but may be compressible and subject to flooding.

Question 5

Which of the three major rock types is formed through the cooling and solidification of magma or lava?

Accepted Answer

Igneous

Answer

Igneous rocks (e.g., granite, basalt) form from the cooling of molten rock; they are typically hard, durable, and used extensively as landscape paving and wall materials.

CLARB - Council of Landscape Architectural Registration Boards Practice Test

CLARB - Council of Landscape Architectural Registration Boards Practice Test

CLARB Soils and Geology 3