My thanks to both him and other critics for motivating me.Much of the Earth's geology consists of successional layers of different rock types, piled one on top of another.
Fundamental to stratigraphy are a set of simple principles, based on elementary geometry, empirical observation of the way these rocks are deposited today, and gravity.
Most of these principles were formally proposed by Nicolaus Steno (Niels Steensen, Danish), in 1669, although some have an even older heritage that extends as far back as the authors of the Bible.
In this situation, the cave contents are younger than both the bedrock below the cave and the suspended roof above.
However, note that because of the "principle of cross-cutting relationships", careful examination of the contact between the cave infill and the surrounding rock will reveal the true relative age relationships, as will the "principle of inclusion" if fragments of the surrounding rock are found within the infill.
The principle of superposition therefore has a clear implication for the age of a vertical succession of strata.