Seasonal dating terms
Richardson, professor of geology at Iowa State University (based on the glossary in Earth: An Introduction to Geologic Change, by S. It followed the Hadean, and lasted from around 3.8 to 2.5 billion years ago.During this time prokaryote life appeared and flourished, and the Earth was characterised by a reducing (anaerobic) atmosphere. Atom The smallest unit that has the chemical characteristics of a particular chemical element.To be most useful, an index fossil must have broad, even worldwide distribution and must be restricted to a narrow stratigraphic range.International Commission on Stratigraphy (ICS) a subordinate body of the International Union of Geological Sciences (an international non-governmental organization devoted to international cooperation in the field of geology) that concerns itself with stratigraphy, geological, and geochronological matters on a global scale. The second era of the Phanerozoic eon, lasting from 251 to 65.5 million ago, and characterised by the dominance of archosaurian reptiles on land, and marine reptiles in the seas. Metamorphism The heating of rocks over long time periods at temperatures which are hot enough to change the crystal structure but not hot enough to completely melt the rock.[den., science] Ice cores can be dated by multiple independent means, with the oldest published date of 140,000 ± 15,000 years for the Vostok core from Antarctica. The other two types of rock are sedimentary, formed by the cementing together of soil or sand, and metamorphic rocks reformed by heat over long periods of time.Index fossil A fossil that identifies and dates the strata in which it is typically found.This website is published by News Corp UK & Ireland Limited, 1 London Bridge Street, London, SE1 9GF. : The following is taken from several on-line sources, chiefly Illustrated Glossary of Geologic Terms by Steven M. Richardson (Englewood Cliffs, NJ, Prentice Hall, 1995); definitions conform generally, and in some cases specifically, to definitions given in Robert L Bates and Julia A Jackson (editors), Glossary of Geology, 3rd ed., American Geological Institute, Alexandria, Virginia, 1987.), and Radiometric Dating A Christian Perspective Dr. Wiens Division of Geological & Planetary Sciences California Institute of Technology reprinted from Graham Kendell archives. Elsberry's Archean The second oldest eon in Earth history.
The term Ediacaran was replaced for a while by Vendian, but now it seems that Ediacaran is back in fashion.Atomic mass number remains constant because the total number of protons and neutrons is unchanged.