Editing River Mole (section)

===Lower Mole <span style="display:none">(geology)</span>===
At Leatherhead the river leaves the chalk bedrock, moving onto [[London Clay]].<ref>{{cite journal |author=Green JFN |year= 1936 |title= Field Meeting in the Region of the River Mole |journal= Proceedings of the Geologists' Association |volume= 47 |pages= 11–14 |doi= 10.1016/s0016-7878(36)80018-2}}</ref> The river meanders across an [[alluvial plain]] between {{cvt|400|and(-)|800|m|yd}} wide towards Cobham, where it begins to descend to a lower flood plain, which broadens as the river turns in an axehead meander. At the east end of Painshill Park, the flood plain narrows into a trench about {{cvt|60|m|yd}} wide, in which the river runs northwards for {{convert|6.5|km|mi|abbr=on}} towards Hersham, where the river enters the flood plain of the River Thames.<ref name=physiography/>

Between Cobham and Esher, the Mole's historic courses have deposited gravel on top of the London Clay.<ref>{{cite journal |author=Monckton HW |year=1904 |title=Excursions to the Farnham Gravel Pits on April 23rd and to the Brickfields and Gravel Pits at Dawley, between Hayes and West Drayton on April 30th 1904 |journal=Proceedings of the Geologists' Association |volume=18 |issue=8 |pages=409–414 |doi=10.1016/s0016-7878(04)80055-5 |url=https://zenodo.org/record/1428520 |access-date=5 July 2019 |archive-date=2 January 2021 |archive-url=https://web.archive.org/web/20210102110414/https://zenodo.org/record/1428520 |url-status=live }}</ref> The depth of the deposits generally varies from {{convert|2.5|to(-)|7|m|ft|0|abbr=on}};<ref name=ChertseyGeology>{{cite book |author=Dewey H |title=The Geology of the county around Windsor and Chertsey |series= Memoirs of the Geological Survey |year=1915 |publisher= British Geological Survey |location=London |pages=71–72}}</ref> the lower layers are generally highly compacted and cemented together with brick-red iron oxide, whereas the upper layers are loosely packed with angular flints and sand.<ref>{{cite journal |author= Hudleston WH |year= 1886 |title= On a recent Section through Walton Common exposing the London Clay, Bagshot Beds, and Plateau-gravel |journal= Quarterly Journal of the Geological Society |volume= 42 |issue= 1–4 |pages= 147–172 |doi= 10.1144/gsl.jgs.1886.042.01-04.18 |s2cid= 129839441 |url= https://zenodo.org/record/1448529 |access-date= 5 July 2019 |archive-date= 2 January 2021 |archive-url= https://web.archive.org/web/20210102110415/https://zenodo.org/record/1448529 |url-status= live }}</ref> Remains of a further gravel terrace, containing cherts and flints to a depth of {{convert|4|m|ft|0|abbr=on}}, line the east side of [[St George's Hill]].<ref name=ChertseyGeology/>