144 Reports and Proceedings — Geological Society of London. 



capable of rising 130 feet above the surface of the ground, and it has 

 a temperature considerably higher than that of the surrounding air. 



This well, the bottom of which, reckoning from the Ordnance 

 datum-line, is now 150 feet lower than that of any other well within 

 the London Basin, has revealed a number of facts which are of the 

 greatest interest to geologists. 



The Tertiary strata passed through present their usual characters. 

 The London Clay has a thickness of 160 feet, the Woolwich and 

 Reading Series of 60 feet, and the Thanet Sand of 23 feet. The usual 

 band of green-coated flints separates the Tertiaries from the Chalk. 



The Chalk was proved to be 671 feet thick under Richmond. 

 Two important horizons, the Chalk Rock and the zone of Behmnites 

 plenus, were recognized in it, and it was thus proved that the Upper 

 Chalk, or Senonian, is 300 feet thick, the Middle Chalk, or Turonian, 

 150 feet, and the Lower Chalk, or Cenomanian (including the Upper 

 Greensand, which is normal in character and about 16 feet thick), 

 less than 250 feet. 



The Gault presents its usual characters, subdivisions, and fossils ; 

 it is 201^ feet in thickness. At its base is the usual band of 

 phosphatic nodules. 



Beneath the Gault was found 10 feet of impure sandy limestone, 

 with but few and imperfect fossils, and a second junction-bed at its 

 base. These beds are probably referable to the Neocomian. 



At this point the boring entered thick beds of oolitic limestone 

 with some subordinate bands of clay. The careful examination of 

 these has revealed the presence of many fossils, Brachiopoda, Bryozoa, 

 and Echinodermata being especially abundant, some of them in a very 

 perfect state of preservation. These fossils prove the strata in which 

 they occur, 87^ feet in thickness, to be of the age of the Great Oolite. 



A careful re-examination of the evidence in the case of the boring 

 made in 1878 at Meux's Brewery, proves that the 64 feet of oolitic 

 limestone, which was there found overlying the Devonian rocks, is 

 also of Great-Oolite age, though deposited under somewhat different 

 conditions from those at Richmond. 



The Great- Oolite strata of Eichmond rest on beds of red and Tariegated sandstones 

 and "marls," the former exhibiting mnch false-bedding. These strata have not 

 yielded any fossils ; but their lithological characters seem to indicate that they belong 

 to the New Eed Sandstone formation. These discoveries have an important bearing 

 on several very interesting geological problems. 



(1) The Great Palaeozoic Eidge beneath the London Basin is shovra to have been 

 overlapped, in part or altogether, by strata of the Lovrer Oolites, the Lias being absent ! 

 That representatives of the Middle Oolites were also present is shown by the derived 

 fossils in the Neocomian strata along the base of the North Downs. 



(2) Pervious beds of the Lower Greensand, which probably underlie part of the 

 Southern Metropolitan area, are proved not to reach so far north as Eichmond. The 

 presence of pervious beds of the New Eed may possibly be found to compensate in 

 some degree for the absence of the Neocomian as a source of water-supply. 



(3) The discussion of these facts throws some new light on the problem of the 

 existence of Coal-bearing strata at workable depths under London. Small particles 

 of anthracite were found in several of the deeper beds at Eichmond, these being 

 probably derived from Coal-seams in the great Palaeozoic axis ; but the presence of 

 Jurassic and Triassic strata shows that a greater thickness of strata will probably 

 have to be pierced in order to reach the coal than was formerly supposed. 



The paper concludes with some notes on the very interesting and beautifully 

 preserved fossils from the Great Oolite beds under London. 



