Editing Tamil Nadu (section)

=== Geology ===
Tamil Nadu falls mostly in a region of low seismic hazard with the exception of the western border areas that lie in a low to moderate hazard zone; as per the 2002 Bureau of Indian Standards (BIS) map, Tamil Nadu falls in Zones II and III.<ref>{{cite web|url=http://asc-india.org/maps/hazard/haz-tamil-nadu.htm|title=Tamil Nadu Hazard Zone map|publisher=Amateur Seismic Centre, Pune|date=30 March 2007|access-date=10 September 2012|archive-date=17 July 2011|archive-url=https://web.archive.org/web/20110717015554/http://asc-india.org/maps/hazard/haz-tamil-nadu.htm|url-status=live}}</ref> The volcanic [[basalt]] beds of the Deccan plateau were laid down in the massive [[Deccan Traps]] eruption, which occurred towards the end of the [[Cretaceous]] period, between 67 and 66 million years ago.<ref>{{cite news|url=https://newsoffice.mit.edu/2014/volcanic-eruption-dinosaur-extinction-1211|title=What really killed the dinosaurs?|publisher=MIT|first1=Jennifer|last1=Chu|date=11 December 2014|access-date=28 August 2023|archive-date=26 December 2014|archive-url=https://web.archive.org/web/20141226120208/http://newsoffice.mit.edu/2014/volcanic-eruption-dinosaur-extinction-1211|url-status=live}}</ref> Layer after layer was formed by the volcanic activity that lasted many years and when the volcanoes became extinct, they left a region of highlands with typically vast stretches of flat areas on top like a table.<ref>{{cite encyclopedia|url=https://www.britannica.com/EBchecked/topic/154969/Deccan|title=Deccan Plateau|encyclopedia=Britannica|access-date=1 January 2016|archive-date=1 May 2015|archive-url=https://web.archive.org/web/20150501005236/http://www.britannica.com/EBchecked/topic/154969/Deccan|url-status=live}}</ref> The predominant soils of Tamil Nadu are [[red soil|red loam]], [[laterite soil|laterite]], [[chernozem|black]], [[alluvial soil|alluvial]] and [[saline soil|saline]]. Red soil, with a higher iron content, occupies a larger portion of the state and all the inland districts. Black soil is found in [[Kongu Nadu|western Tamil Nadu]] and parts of the southern coast. Alluvial soil is found in the fertile Kaveri delta region, with laterite soil found in pockets, and saline soil across the coast where the evaporation is high.<ref>{{cite report|url=https://dolr.gov.in/sites/default/files/TAMILNADU%20STATE%20PERSPECTIVE%20%26%20STRATEGIC%20PLAN.pdf|title=Strategic plan, Tamil Nadu perspective|publisher=[[Government of India]]|access-date=1 December 2023|page=20|archive-date=9 March 2024|archive-url=https://web.archive.org/web/20240309100229/https://dolr.gov.in/sites/default/files/TAMILNADU%20STATE%20PERSPECTIVE%20%26%20STRATEGIC%20PLAN.pdf|url-status=live}}</ref>