Keywords: The Quarterly journal of the Geological Society of London (13958812853).jpg 1866 <br> FISHER WARP <br> 561 <br> subsoil This I believe to be the sections of channels of drainage <br> and that the drainage carries forward some material with it Some <br> such action as this may account for the flat-topped elevations like <br> the tenons in the framework of a dissected puzzle which often occur <br> in or near the line of junction of the warp with the subsoil espe- <br> cially if I mistake not where the latter contains calcareous matter <br> and has suffered partial solution The erosion at the bottom of two <br> contiguous subterranean channels would leave an elevated ridge be- <br> tween them and the superincumbent soil sinking in a general mass <br> would then flatten the crest of the ridge By a continuance of such <br> a process with slightly shifting directions in the drainage those <br> complicated foldings would be formed the cause of which at first <br> sight seems so incomprehensible <br> Fig 8 Section of a Pit in Victoria Road Cambridge <br> e '° <br> a Warp <br> b White sandy brick-earth <br> c Yellowish sandy earth <br> d Fine sandy gravel <br> e Yellowish brick-earth <br> / Fine gravel more contorted than the <br> layers above and below <br> g Sand <br> The sands contain Bythinia c <br> Contortions of the kind alluded to when occurring in gravel-beds <br> are sometimes explained by the action of floating ice ; but that cause <br> can only have operated under water These contortions have in some <br> way or another resulted from subaerial causes ; and though I see <br> difficulties I think this explanation may be the right one <br> In the instances from the Cambridge gravel-pits the percolation <br> and consequent erosion seem to have taken place in the layer be- <br> neath the ductile clay which is folded into such remarkable forms <br> Had it been on its upper surface the layer must have been cut through <br> It must be recollected that slight inequalities slowly formed in the sur- <br> face of the ground by such subsidences would be continually levelled <br> by the action of rain herbage and worms <br> The next question which I propose to enter upon relates to the <br> age of the warp The causes to which I have attributed its forma- 36165014 111477 51125 Page 561 Text v 22 http //www biodiversitylibrary org/page/36165014 1866 Geological Society of London NameFound Bythinia NameConfirmed Bythinia EOLID 4814421 NameBankID 4097537 NameFound Victoria NameConfirmed Victoria EOLID 34123 NameBankID 897688 Biodiversity Heritage Library The Quarterly journal of the Geological Society of London v 22 1866 Geology Periodicals Smithsonian Libraries bhl page 36165014 dc identifier http //biodiversitylibrary org/page/36165014 smithsonian libraries Information field Flickr posted date ISOdate 2014-04-21 Check categories 2015 August 26 CC-BY-2 0 BioDivLibrary https //flickr com/photos/61021753 N02/13958812853 2015-08-26 06 54 33 cc-by-2 0 PD-old-70-1923 The Quarterly journal of the Geological Society of London 1866 Photos uploaded from Flickr by FÌ using a script |