• journal_title：Journal of the Geological Society
• Contributor：ALAN G. SMITH ; KEVIN T. PICKERING
• Publisher：Geological Society of London
• Date：2003-
• Format：text/html
• Language：en
• Identifier：10.1144/0016-764902-115
• journal_abbrev：Journal of the Geological Society
• issn：0016-7649
• volume：160
• issue：3
• firstpage：337
• section：Short Communication

We propose a unifying explanation for the four major icehouses during the past c.620 million years: earliest Oligocene to Present; early Carboniferous to early Permian; late Ordovician and late Vendian (the ‘snowball Earth’) all of which appear to have been initiated as a result of two plate-tectonic processes. The first moved some continents into polar latitudes; while there the second process opened and closed oceanic low latitude gateways that changed global oceanic circulation from one with important circum-equatorial currents (greenhouse) to one with inhibited circum-equatorial deep-water currents (icehouse) and more restricted oceanic gyres.