Nido Formation

The Nido Formation is a stratigraphic unit of Neogene age in northwestern British Columbia, Canada.

Nido Formation
Stratigraphic range: 7.8–4.4 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Paleogeological map of the Nido Formation at the end of the Nido eruptive period
Type	Geological formation[1]
Unit of	Mount Edziza volcanic complex[2]
Sub-units	Kounugu Member, Tenchen Member[1]
Underlies	Spectrum Formation, Pyramid Formation, Ice Peak Formation, Big Raven Formation, Edziza Formation[1]
Overlies	Raspberry Formation, Armadillo Formation, Little Iskut Formation[1]
Lithology
Primary	Alkali basalt, hawaiite[1]
Other	Fluvial gravel[1]
Location
Coordinates	57.5°N 130.6°W / 57.5; -130.6[2]
Region	British Columbia[1]
Country	Canada[1]
Type section
Named for	Nido Creek[1]
Named by	Souther et al., 1984[3]

Name

The Nido Formation takes its name from Nido Creek, a stream flowing northeast from the eastern flank of Mount Edziza into Nuttlude Lake.^[1][4][5] Nido means "white man" in the Tahltan language.^[5]

Geology

The Nido Formation has a volume of 127 km³ (30 cu mi), making it the second most voluminous geological formation of the Mount Edziza volcanic complex after the Armadillo Formation.^[1][2] It overlies the Raspberry, Armadillo and Little Iskut formations, all of which are Miocene in age. Also underlying the Nido Formation are pre-Tertiary rocks of the Stikinia terrane. Overlying the Nido Formation are the Spectrum, Pyramid, Ice Peak, Edziza and Big Raven formations which are of Pliocene age and younger.^[1]

Two subunits comprise the Nido Formation, namely the Tenchen Member and the Kounugu Member. Both members are separated by the Armadillo Highlands in the middle of the Mount Edziza volcanic complex. The Tenchen Member forms a lava field north of the Armadillo Highlands while the Kounugu Member forms a lava field south of the highlands.^[1]

The Nido Formation consists of alkali basalt and hawaiite lava flows that issued from multiple eruptive centres. K–Ar dating has yielded ages of 7.8 ± 0.3 million years, 5.5 ± 1.6 million years, 4.5 ± 0.3 million years and 4.4 ± 0.5 million years for Nido alkali basalt.^[1]

See also

• Volcanism of the Mount Edziza volcanic complex