ASBOG Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

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.