Frasnian

EtymologyName formalityFormalUsage informationCelestial bodyEarthRegional usageGlobal (ICS)Time scale(s) usedICS Time ScaleDefinitionChronological unitAgeStratigraphic unitStageTime span formalityFormalLower boundary definitionFAD of the conodontLower boundary GSSP, Montagne Noire, France
43°30′12″N3°05′12″E / 43.5032°N 3.0868°E / 43.5032; 3.0868Lower GSSP ratified1986Upper boundary definitionFAD of the conodont Palmatolepis triangularis
LAD of the conodontsAncyrodella and Ozarkodina and the goniatites and BeloceratidaeUpper boundary GSSPCoumiac quarry, Montagne Noire, France
43°27′41″N3°02′25″E / 43.4613°N 3.0403°E / 43.4613; 3.0403Upper GSSP ratified1993

The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from 382.31 million years ago to 372.15 million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage.

Major reef-building was under way during the Frasnian Stage, particularly in western Canada and Australia. On land, the first forests were taking shape. In North America, the Antler orogeny peaked, which were contemporary with the Bretonic phase of the Variscan orogeny in Europe.

The Frasnian coincides with the second half of the "charcoal gap" in the fossil record, a time when atmospheric oxygen levels were below 13 percent, the minimum necessary to sustain wildfires.

North American subdivisions of the Frasnian include

• West Falls Group
• Sonyea Group
• Genesee Group