Final answer:
Layers that are densely stratified are considered stable because they have undergone significant deposition and have settled into a consistent sequence over time. This stability is beneficial for dating geological phenomena and understanding the relative positions of different layers.
Step-by-step explanation:
Layers that are densely stratified are considered stable because they have undergone significant deposition and have settled into a consistent sequence over time. As a result, these layers are less likely to experience disturbances or shifting, making them more stable. For example, in geology, if a specific set and sequence of strata is noted in several sites and over a large enough area, it can be assumed that the ages will be the same for the same strata at different locations in the area. This insight enabled scientists to use the structures of soils and rocks to date phenomena throughout a region based on their relative positions.