Feature Depth Top

The depthTop of a Feature is the measured depth where you first encountered it as you dug down — the level at which the stain, fill, or stones of the feature appeared. Paired with depthBottom, it brackets the feature's full vertical extent, which matters because the depth at which a feature begins is a clue to its relative age: features that appear higher are generally later than those that only emerge deeper. Recording depthTop consistently against your unit datum lets you reconstruct the stratigraphic sequence and correlate a feature with the StratigraphicLayer it cuts into. The field is optional, used when a meaningful top can be measured.