ASBOG Practice Exam

According to the Rule of V's, what does a wider V indicate about the dip of the bed crossing a valley?

1. It is horizontal

2. It is steep

3. It is shallow

4. It is variable

The correct answer is: It is steep

The Rule of V's is a fundamental principle used in geology and hydrology to interpret the relationship between valley shapes and the dip of rock layers. When examining a valley formed by a river or stream, the shape of the valley and the width of the V formed at the valley's bottom can indicate the dip of the underlying rock layers. A wider V typically suggests that the bedrock or strata crossing the valley is dipping steeply. This occurs because the rapid erosion of steeper slopes forms a narrower valley, while wider valleys often form when the underlying layers dip at a more acute angle. Consequently, the wide V shape points towards the presence of steeply dipping beds. In contrast, a horizontal dip would likely produce a more level valley bottom with less pronounced V formations, and a shallow dip might not create a very sharp or wide V shape either. Therefore, when interpreting valley shapes through the Rule of V's, recognizing that a wider V indicates steep dips is crucial in geological assessments and mapping.