Look up quartary or quaternary in Wiktionary, the free dictionary.

The Quaternary is a geologic period.

Quaternary (an adjective meaning "fourth in order" or "composed of four items") may also refer to:

• Quaternary (chemistry) (see also Quaternary compound and Quaternary phase)
• Quaternary structure of proteins
• Quaternary sector of the economy, which encompasses knowledge-based services
• Quaternary care, health care that includes highly specialized or experimental treatments
• Quaternary numeral system (base-4) in mathematics
• Quaternary counting system, as used in some human languages
• Quaternary (EP), an album by Mötley Crüe
• Quaternary star system, a star system that contains four stars

• All pages with titles beginning with Quaternary
• All pages with titles containing Quaternary
• Quinary, positional number system with base 5
• Ternary (disambiguation)
• Tertiary (disambiguation)

This disambiguation page lists articles associated with the title Quaternary.
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