Editing Reigate (section)

==Geography==
{{see also|Surrey#Climate}}
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===Location and topography===
Reigate is in central [[Surrey]], around {{cvt|18.94|mi|km|adj=ri0|0}} south of central London and {{cvt|9|mi|km}} north of [[Gatwick Airport]].<ref>{{cite web |url= https://www.reigate.ac.uk/job-vacancies/about-reigate-and-orientation/ |title= About Reigate |publisher= Reigate College |access-date= 21 June 2023 }}</ref> The town is in the [[Vale of Holmesdale]], below the [[North Downs]] escarpment. The average elevation in the centre is {{cvt|80|m|ft}} above [[ordnance datum]] (OD) and the area is drained by the Wallace Brook and its tributaries, which feed the [[River Mole]].<ref>{{cite web |title= Reigate Conservation Area appraisal |url= https://www.reigate-banstead.gov.uk/download/downloads/id/2294/reigate_conservation_area_character_appraisal_-_draft.pdf |date= February 2015 |publisher= Reigate & Banstead Borough Council |access-date= 21 June 2023 |archive-url= https://web.archive.org/web/20230621143636/https://www.reigate-banstead.gov.uk/download/downloads/id/2294/reigate_conservation_area_character_appraisal_-_draft.pdf |archive-date=  21 June 2023 }}</ref><ref>{{cite web |url= https://www.gov.uk/government/publications/mole-catchment-abstraction-licensing-strategy |title= Mole Abstraction licensing strategy |author= <!--Not stated--> |year= 2013 |publisher= Environment Agency |access-date= 27 April 2020 |archive-url= https://web.archive.org/web/20190723221117/https://www.gov.uk/government/publications/mole-catchment-abstraction-licensing-strategy |archive-date= 23 July 2019 |url-status= live }}</ref>

===Geology===
Woodhatch lies on the [[Weald Clay]], a [[sedimentary rock]] primarily consisting of mudstone that was deposited in the [[early Cretaceous]]. Much of Reigate is on the [[stratum|strata]] of the [[Lower Greensand Group]]. This group is multi-layered and includes the sandy Hythe Beds overlain by the clayey Sandgate Beds, which together form the high ground of Priory Park.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=47}}</ref><ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=51}}</ref> Reigate Heath and the town centre are on quartz-rich Folkestone Beds<ref name=Dines_1933_11-13>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|pp=11–13}}</ref> and the water-filled part of the castle [[moat]] is dug into narrow band of clay present in the sandstone.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=77}}</ref> To the north of the railway line is the [[Gault|Gault Formation]], a stiff, blue-black, [[shale|shaly]] clay, deposited in a deep-water marine environment.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|pp=80–82}}</ref> At the base of the North Downs is a thin outcrop of [[Upper Greensand Formation|Upper Greensand]], above which lies the [[Chalk Group]].<ref name=BGS_Gallois>{{harvnb|Gallois|Edmunds|1965}}</ref>

[[File:- Barons' Sand Caves and Mine, Reigate (4791117611).jpg|thumb|One of the tunnels excavated through the Folkestone Beds beneath [[Reigate Castle]]]]
Weald clay was dug for brickmaking at Brown's Brickyard in Woodhatch.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=37}}</ref> Building sand was excavated from Barnards Pit, to the west of the town, and at Wray Common Road to the east.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=179}}</ref> [[Stratum|Seams]] of [[silver sand]] which occur in the Folkestone Beds were quarried for glass making and the caves beneath the castle may originally have been excavated for this purpose, before being used as cellars. There is also evidence of [[ironstone]] extraction in the town, although this practice is thought to have ceased by 1650.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=177}}</ref>

[[Reigate Stone]] was mined from the Upper Greensand from medieval times until the mid-20th century<ref name=Michette_2020>{{cite journal |vauthors= Michette M, Viles H, Vlachou C, Angus I |year= 2020 |title= The many faces of Reigate Stone: an assessment of variability in historic masonry based on Medieval London's principal freestone |journal= Heritage Science |volume= 8 |page= 80 |doi= 10.1186/s40494-020-00424-w |doi-access= free }}</ref> and was used in the construction of several local buildings, including the castle, [[Reigate Priory]] and St Mary's Church. To the north of the town are the remains of several old chalk pits<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=100}}</ref> and lime is thought to have been produced at a site at the base of [[Colley Hill]], although the age of the workings is uncertain.<ref>{{harvnb|Dines|Edmunds|Chatwin|Stubblefield|1933|p=180}}</ref>