A fossil that is useful for dating and correlating the strata in which it is found.
〔地质〕标准化石
Example sentencesExamples
These rocks are interbedded in Emsian marine sedimentary successions that are well documented by index fossils.
Possibly the species will prove to be an index fossil for the lower Frasnian and uppermost Givetian of the Sauerland and the Maider in Morocco, ‘Ait Ou Amar’.
This ‘dating’ is based on the presence of the ammonite index fossil Dactylioceras tenuicostatum.
Carboniferous and Permian strata often contain useful index fossils belonging to this group.
They are very abundant in some Paleozoic formations and include useful index fossils.
Stratigraphic occurrences of Carcineretes in the Caribbean Province suggest that this crab should be regarded as an index fossil for the early Maastrichtian.
Definition of index fossil in US English:
index fossil
noun
Geology
A fossil that is useful for dating and correlating the strata in which it is found.
〔地质〕标准化石
Example sentencesExamples
They are very abundant in some Paleozoic formations and include useful index fossils.
Possibly the species will prove to be an index fossil for the lower Frasnian and uppermost Givetian of the Sauerland and the Maider in Morocco, ‘Ait Ou Amar’.
These rocks are interbedded in Emsian marine sedimentary successions that are well documented by index fossils.
This ‘dating’ is based on the presence of the ammonite index fossil Dactylioceras tenuicostatum.
Stratigraphic occurrences of Carcineretes in the Caribbean Province suggest that this crab should be regarded as an index fossil for the early Maastrichtian.
Carboniferous and Permian strata often contain useful index fossils belonging to this group.