Palaeos: | Geosphere | |
THE EARTH | Geosphere |
By "geosphere" is meant in the broad sense the inanimate part of the Earth. In a sense the moon (or any other lifeless world) is a geosphere.
Planet Earth is distinguished from all other geospheres in this solar system (and probably in many others as well), in that it also contains life (biosphere) and intelligence (noosphere).
The geosphere or rocky Earth formed from collisions of planetoids. During the turbulent Priscoan/Hadean era, heavy metallic elements sink down to become the inner core, lighter ones rise to be the mantle. Formation of the crust as a sort of "scum" floating on the mantle. There was a reducing atmosphere through outgassing from volcanoes, and a planetary ocean.
During the Archean there is the formation of the continents and the archaic regime of Continental drift.
The Proterozoic era saw several Ice Ages, and the start of the modern regime of Continental drift.
Plate Tectonics |
Palaeogeography |
plate tectonics and continental drift icons from This Dynamic Earth:The Story of Plate Tectonics, by W. Jaquelyne Kious and Robert I. Tilling, (on-line edition)
Links |
Dynamic Geological Time Scale by Bob Beatty. See also his RAB diagrams. Planetology based on engineering principles - very interesting!
On-line essays in Earth Sciences - heaps of stuff on Properties of the Solid Earth, Dynamics of the Solid Earth and Other Planets, Space Sciences, Atmospheric Sciences, Hydrology, and Ocean Sciences. Part of the American Geophysics Union site
Geology Glossaries - lists of links to on-line glossaries of geological terms.
Recalibration of the geomagnetic polarity timescale - J.E.T. Channell - an on-line hypertext on Geomagnetism and Paleogeomagnetism. Very technical. Deals mainly with the period from the late Jurassic to the present.