Biostratigraphy Flashcards
What is a zone?
A fundamental division recognised by biostratigraphers, using fossils to date and correlate. On regional scales
What is a biozone?
Rocks that are characterised by one or more specified types of index fossils. On global scales.
What hierarchy do zones fit into?
Zones<Stages<Series
Give five characteristics of good zonal fossils
Short time range with rapid evolution.
Distinct morphology.
Wide distribution.
Facies independent.
Highly abundant.
What four assumptions must be true for biostratigraphy to be viable?
Each species has its own unique geological range and one species lives for a finite time, has not evolved twice, and its extinction in permanent. Rocks that contain a species were deposited at the time that the species existed. The principle of faunal succession is correct.
What is a Lazarus taxon?
A taxon that disappears from the fossil record close to an extinction horizon but then reappears laters. Such as the coelacanth fish
What would have to be disproved in order to disprove the principle of faunal succession?
Evolution
What can affect the requirement for rocks to be deposited at the same time as the species fossilised inside them lived?
Sediment reworking