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Supercontinents Reference Libraries

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North America
2013-02-18 15:40:12

North America is a continent completely within the Northern Hemisphere and almost completely within the Western Hemisphere. It’s also considered a northern subcontinent of the Americas. It’s bordered to the north by the Arctic Ocean, to the west and south by the Pacific Ocean, to the southeast by South America and the Caribbean Sea, and to the east by the Atlantic Ocean. This continent...

Paleoproterozoic
2012-11-18 19:08:04

The Paleoproterozoic is the first of three subdivisions of the Proterozoic Eon (occurring from 2.5 billion to 1.6 billion years ago (Ga). This period is marked by the first stabilization of the continents, and also when cyanobacteria--a type of bacteria that uses biochemical processes of photosynthesis to produce oxygen--evolved. Experts have found paleontological evidence that during at...

Archean
2012-10-22 14:17:38

The Archean (formerly Archaeozoic) is a geologic eon between the Hadean and Proterozoic eons. The Archean Eon begins at roughly 3.8 billion years ago (Ga) and ends at about 2.5 Ga. But unlike all other geological ages, which are based on stratigraphy, The Archean eon is defined chronometrically. The lower boundary of 3.8 Ga has also not been officially recognized by the International Commission...

Word of the Day
bretelles
  • In dressmaking, straps running from the belt in front over the shoulders to the belt in the back, with more or less elaboration of trimming and outline. They usually broaden at the shoulder and narrow toward the waist.
The word 'bretelles' comes from a French word meaning 'braces'.