Editing Epsom (section)

===Geology===
Like many of the towns and villages between [[Croydon]] and [[Guildford]], Epsom is a [[strip parish]] and [[spring line settlement]]. The areas to the south and east of the town lie on the [[Chalk Group|chalk]] of the [[North Downs]] and the centre, north and west are on the [[London Clay]]. Separating the two, and running in parallel bands along a north–south axis, are narrow [[outcrop]]s of [[Thanet Formation|Thanet Sands]] and the [[Lambeth Group]].<ref name=Abdy_2001_p1/><ref name=Geology_map>{{cite web |url=https://www.epsom-ewell.gov.uk/sites/default/files/documents/residents/planning/planning-policy/SFRA%20APPENDIXH.pdf |title=Strategic Flood Risk Assessment: Appendix H (geology and groundwater) |author=<!--Not stated--> |date=May 2008 |publisher=Epsom & Ewell Borough Council |access-date=30 July 2021 |archive-date=1 August 2021 |archive-url=https://web.archive.org/web/20210801202615/https://www.epsom-ewell.gov.uk/sites/default/files/documents/residents/planning/planning-policy/SFRA%20APPENDIXH.pdf |url-status=live}}</ref><ref name=Lee_1849>{{cite report |url=https://eehe.org.uk/?p=64347 |title=Report to the General Board of Health |last=Lee |first=William |year=1849 |access-date=30 July 2021 |archive-date=22 June 2021 |archive-url=https://web.archive.org/web/20210622160317/https://eehe.org.uk/?p=64347 |url-status=live}}</ref> The chalk is a natural [[aquifer]] and [[tributary|tributaries]] of the [[Hogsmill River]] rise at several points along the boundary between the [[permeability (Earth sciences)|permeable]] and impermeable rock types. During the late 17th and early 18th century, the spring on Epsom Common was thought to have healing properties and the waters were later found to be rich in [[magnesium sulfate|magnesium sulphate]], which became known as "[[Epsomite|Epsom salts]]".<ref name=Lee_1849/><ref>{{harvnb|Osbourne|Weaver|1996|p=52}}</ref>