Geological history of Earth Reference Libraries

Page 1 of about 6 Articles
2013-04-19 19:33:20

Rainforests are forests that are characterized by high levels of rainfall, with definitions based on a minimum usual annual rainfall of about 68 to 78 inches. The monsoon trough, or otherwise known as the intertropical convergence zone, holds an important role in producing the climatic conditions that are essential for the Earth’s tropical rainforests. About 40 to 75 percent of all biotic...

2013-04-02 09:46:56

Desertification is a form of land degradation in which a comparatively dry land area becomes more and more arid, normally losing its bodies of water along with its wildlife and vegetation. This is a result of a variety of factors, such as climate change and human activities. Desertification is an important global, ecological, and environmental issue. There is substantial controversy over the...

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...

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...

Hadean Eon
2012-06-26 19:51:17

The Hadean is the unofficial geological period of time that lies just before the Archean time period. The Hadean began with the formation of the Earth roughly 4.5 billion years ago (Ga) and ended about 3.8 Ga; the latter date varies according to different sources. Hadean is derived from Hades, Greek for “underworld,” referring to the hellish conditions on the planet at the time. The term...

Wegener Alfred Lothar
2013-03-16 00:00:00

Alfred Lothar Wegener (November 1, 1880 "“ November 2, 1930) was a German scientist, geologist, and meteorologist. He is best known for establishing the theory of the continental drift. His 1915 theory of continental drift surmised that the continents were slowly floating around the Earth. Most of his basis was strictly circumstantial evidence, and further he was not able to exhibit a...

Word of the Day
  • In Roman antiquity, the return of a person who had been banished, or taken prisoner by an enemy, to his old condition and former privileges.
  • In international law, that right by virtue of which persons and things taken by an enemy in war are restored to their former status when coming again under the power of the nation to which they belonged.
The word 'postliminy' comes from a Latin word meaning 'threshold'.