Evidence from the magnetic field fossilized in sedimentary rocks suggests that, more than 600 million years ago, ice occupied tropical latitudes. A popular explanation for these findings, the Snowball Earth concept, envisages a fully frozen Earth for millions of years, caused by a runaway ice
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/sedimentary-challenge-snowball-earth
[2] http://admin.indiaenvironmentportal.org.in/category/author/philip-allen
[3] http://admin.indiaenvironmentportal.org.in/category/author/james-l-etienne
[4] http://admin.indiaenvironmentportal.org.in/category/journal/nature-geoscience
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-science