'The principle of faunal succession, also known as the law of faunal succession, is based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.' (From the Principle of faunal succession article on Wikipedia. See that page for a brief overview of the topic.)
This topic overlaps with many others:
For information about index fossils, relative dating of strata, and related claims of circular reasoning, see the geologic column page.
For resources dealing generally with problems of the claim of a catastrophic global Flood, see the Flood geology page.
For information about the patterns of fossil distribution throughout and within the strata, and also geographically, along with the implications for evolution or the biblical Flood, see the sorting/distribution of fossils page.
For information about the succession of changes through the strata and what they tell us about evolution, as well as resources dealing with claims about gaps in the fossil record, see the fossil record page and the transitional fossils page..