index fossil

n. The fossil remains of an organism that lived in a particular geologic age, used to identify or date the rock or rock layer in which it is found. Also called guide fossil.

index fossil

n (Geological Science) a fossil species that characterizes and is used to delimit a geological zone. Also called: zone fossil

in′dex fos`sil

n. a widely distributed fossil, of narrow range in time, regarded as characteristic of a given geological formation and used esp. in determining the age of related formations. [1895–1900]

index fossil

- One useful for dating and demonstrating the relation between strata in which it is found.See also related terms for useful.

Thesaurus

Noun

index fossil - a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is foundguide fossilfossil - the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil

Index Fossil

index fossil

[′in‚deks ‚fäs·əl] (paleontology) The ancient remains and traces of an organism that lived during a particular geologic time period and that geologically date the containing rocks.

Index Fossil

fossil remains of an organism that are typical of the sedimentary beds of a certain geological age and, therefore, are frequently used in identifying related beds from different regions. All index fossils are important in stratigraphy because they typically are of broad geographic distribution and narrow vertical distribution (because the organisms existed for a short time, they form relatively thin deposits). Their skeletons generally have specific characteristics in construction that make identification easy, even under field conditions.

Modern paleontology is based on the study of a whole set of fossil remains, not individual index fossils, because the use of index fossils as the only criterion in establishing the age of deposits may lead to erroneous conclusions. Nevertheless, index fossils are very useful for preliminary orientation in geological surveying, especially under field conditions.

V. N. SHIMANSKII

index fossil

index fossil

index fossil

in′dex fos`sil

index fossil

Index Fossil

index fossil

Index Fossil

index fossil

Synonyms for index fossil

noun a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found

Synonyms

Related Words