Million Years

Circum-Superior Belt - Geology - Geologic Features
... volcano-sedimentary series, the first ranging from 2,170 to 2,140 million years old and second ranging from 1,883 to 1,870 million years old ... The youngest magmatic series (1883-1870 Ma) contains 1,880 million-year-old carbonatites and lamprophyres. 1,883 to 1,874 million-year-old mafic and a few ultramafic magmas comprise the Willbob and Hellancourt formations and Montagnais sills ...

Saxothuringian Zone - Geology
... sequence is assumed to be continuous from the Ediacaran to the Visean (330 million years ago) ... during the Cadomian orogeny (in the Ediacaran, 650-550 million years ago) and intruded by felsic plutons during the Cambrian and Ordovician (540-420 million years ago) ... of Ordovician to Devonian age (480-360 million years old) and early Paleozoic mid-oceanic ridge basalts ...

Cricetulodon
... close relatives in the Cricetodon-Ruscinomys group, which lived in total for 17 million years from 20 million years ago to approximately 3 million years ago ...

List Of South American Mammals
... the Atlantic from Africa by the Oligocene epoch or slightly earlier, 25 million or more years ago ... having migrated from North America via Central America during the past seven million years as part of the Great American Interchange this invasion, which peaked around three million years ago, was made ... and may have lasted up to several thousand years ...

Stellar Kinematics - Kinematic Groups - Stellar Associations - OB Associations
... short-lived, and will expire as supernovae after roughly a million years ... As a result, OB associations are generally only a few million years in age or less ... The O-B stars in the association will have burned all their fuel within 10 million years ...