Keywords: The Quarterly journal of the Geological Society of London (13071167613).jpg 396 <br> PROCEEDINGS OF THE GEOLOGICAL SOCIETY June 19 <br> don Clay capped by tlie Lower Bagshot sand and Bagshot pebble- <br> beds and when in tbe indentations and inlets so eroded a thick- <br> ness considerably less than the mass of this formation further to the <br> north in Norfolk Suffolk and north Essex had been accumulated <br> Pigs 1-3 ” Diagram Sections showing the relations of the Middle <br> and Upjper Glacial deposits to the Valley of the Thames <br> Valley of the <br> Chelmer <br> Nortli side of the Valley of the <br> Thames valley Chelmer <br> 5 Middle Glacial beds <br> 6 Upper Glacial clay occasional patches <br> of shingly gravel The horizontal <br> lines indicate the sea-level of each <br> successive stage <br> North side of the <br> Thames yalley <br> 1 Chalk <br> 2 Lower London Tertiaries <br> 3 London clay <br> 4 Lower Bagshot sand <br> 4' Bagshot pebbles <br> Fig 2 shows the commencement of the submergence which with <br> a total change in the sediment introduced the Upper Glacial forma- <br> tion or Boulder-clay During this incipient submergence and <br> after the change of sediment had occurred the coast-erosion car- <br> ried the shore back from the points marked a at which it stood <br> at the close of the Middle Glacial formation to the point marked <br> h ; the new deposit of Boulder- clay was spread over the interval <br> being underlain here and there only by a feeble bed of shingly <br> gravel 6' very distinguishable from the thick sands and gravels <br> of the Middle Glacial period and marked in figs 2 and 3 Fig 3 <br> shows the stage when complete submergence had been etiected and <br> a thickness of Upper Glacial clay spread over the entire area As <br> this deposit where it has most escaped denudation still retains a <br> thickness of 160 feet as in Cambridgeshire and Huntingdonshire <br> and presents so uniform a character of slow and steady accumulation <br> by the outspread of water-borne clay- sediment accompanied by the <br> dropping of chalk-debris from ice there is but little room to doubt <br> its having spread over the counties of Surrey and Kent as weU as <br> Essex in great thickness although from its attenuation by denu- 36345151 112028 51125 Page 396 Text v 23 http //www biodiversitylibrary org/page/36345151 1867 Geological Society of London Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 23 1867 Geology Periodicals Smithsonian Libraries bhl page 36345151 dc identifier http //biodiversitylibrary org/page/36345151 smithsonian libraries Information field Flickr posted date ISOdate 2014-03-10 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/13071167613 2015-08-26 13 52 46 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1867 Photos uploaded from Flickr by Fæ using a script |