Latest Petrological Database of the Ocean Floor Stories
SAN FRANCISCO, January 7, 2014 /PRNewswire/ -- Elsevier [http://www.elsevier.com/wps/find/homepage.cws_home ], a world-leading provider of scientific, technical and medical
Researchers at Columbia University's Lamont-Doherty Earth Observatory recently resolved a long-standing contradiction about the workings of the deep Earth. For years, many geochemists have argued that parts of the deep mantle remain unchanged since the formation of the Earth, whereas many geophysicists and geodynamicists have held that the entire mantle has been convecting (moving and mixing) over geological time.
- A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.