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VIII. — Observations on a Well dug on the South Side of Hampstead 



Heath. 



By NATHANIEL THOMAS WETHERELL, Esq., F.G.S. 



[Read June 4, 1834.] 



A. WELL dug at Lower Heath, Hampstead, in 1833, yielded a considerable 

 number of fossils, and in consequence of the London clay having been cut 

 entirely through, and the plastic clay to some depth, it became an object of 

 interest to the geologist. 



It is well known that a great part of the heath is covered with sand, which 

 has been described as belonging to the upper marine formation*. At the 

 southern part, however, the sand gradually disappears, and the clay is met 

 with on the surface, and it is at this part that the well was made. 



The following is a section of the well. 



London Clay 285 feet. 



Rock 5 



Plastic Clay 40 



330 feet. 



The London clay for the first thirty feet, was of a loose texture and reddish 

 brown colour, and contained a good deal of decomposing pyrites and selenite. 

 From 30 feet to 200 feet it varied in colour from blue to dark brown, and 

 contained many septaria. The lower part was as usual very sandy. At 260 

 feet there were a few fruits and seeds, the former being of the same descrip- 

 tion as fruits found at Sheppy, and the latter being similar to the seeds ob- 

 tained at the Highgate Archway. I have a cylindrical piece of pyrites, radia- 

 ting from the centre, very like that which occurs in the chalk. I mention this 

 circumstance, because the pyrites 1 had hitherto met with in the London clay 

 were irregular nodules, or flat masses, without any radiation internally. It 

 was found 265 feet from the surface. Between the last-mentioned depth and 

 285 feet, the bottom of the formation, the clay abounded with vegetable re- 

 mains in a compressed and decomposing state. The fossil copal, or Highgate 

 resin, I believe was not met with. 



* Outlines of the Geology of England and Wales, p. 14, 1822. 



