every summer, pollens fly past Lake Van in Turkey. Pollens scattered in the air by various means get deposited on the lake's bed. Then a layer of mud covers it. This phenomenon repeats itself every year. An inch-thick layer of lime
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/turkish-pollen-deposited-lake-bed-helps-track-climate-history
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/down-earth
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lakes
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/history
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/turkey
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate