ASBOG Practice Exam

What features do map symbols relating to folds typically include?

1. A line tracing the fold axis

2. An indication of the fold's age

3. A color gradient for elevation

4. A description of rock type

The correct answer is: A line tracing the fold axis

Map symbols relating to folds primarily include a line tracing the fold axis. This line represents the central axis of the fold, which is critical for understanding the geometry and orientation of the fold structure within the geological formation. It provides essential information regarding how the layers of rock are bent and how they behave in response to tectonic forces. While other features like indications of the fold's age, color gradients for elevation, or descriptions of rock types can be part of geological maps, they are not specifically representative of folds themselves. The age of the fold can be inferred from the surrounding geology or stratigraphy, color gradients relate to elevation changes, and descriptions of rock type provide information on the material rather than the structural features of the fold. Thus, the line tracing the fold axis is the most relevant symbol to identify and understand fold structures in geological maps.