10 ME. a. W. LAMPLUGH ON THE JUXCTIOJS^ OF [vol. Ixxviii^ 



recently quarried away, as indicated in the figure. When I saw 

 the section in the preceding spring the workmen were breaking 

 through this table of limestone, which was 9 to 12 inches thick,, 

 and 10 or 12 feet long, lying everywhere in one plane immediately^ 

 under the topmost la3'er of iron-grit. The rock was, as usual,, 

 full of fossils, and was similar in all respects to the lenticles seen 

 and described 18 years ago. 



It has occasionally happened since that time that no limestone 

 has been met wath in the pit for three or four years in succession,, 

 but every fresh patch exposed has been on exactly the same 

 stratigraphical horizon, and has presented the same lithological 

 peculiarities. 



The sharp line between the capping iron-grit band and the 

 bottom of the Gault in the above section marks an interval of time 

 and of non-deposition at this spot, on which fresh light was fortu- 

 nately thrown b}^ the workings in Garside's pit immediately on 

 the south, before they were suspended some 15 years ago. These 

 workings will be described next. 



Garside's old She n ley pit. — In 1902 the section in this 

 pit was too near the outcrop of the base of the Gault to show a 

 clear succession, there being only about 4 feet of disturbed and 

 weathered clay overlying the capping of iron-grit and breccia 

 above the ' silver sand.' But, when I revisited the locality in the 

 folloAving summer (1903), fresh sections had been cleared in the 

 western j)''^i''t of the pit, and its north-and-south face revealed 

 the gradual incoming of a wedge of calcareous greensand between 

 the iron-grit floor and the Gault. The sections were practically a 

 southward continuation of those opened up by Harris's pit. The 

 Basement beds sloped down to 20 to 30 feet below their level in 

 the present exposure at Harris's. The following details are from 

 my note-book. 



Section at the west side of Garside's old pit, August IStli, 1903. 

 Surface, about 350 feet O.D. 



Thickness in feet. 



ZY 



-V. Stiff grey-blue claj', with a few stones (probably mostly 'creep') 4 



r Eatlior pale blue clay with ferruginous bands, somewhat disturbed. ") « 



, 3 ' Inoceramus concentricus ' plentiful in one band. ) 



■ 1 Darker blue and ferruginous brownish-blue claj', j-ellowish and 7 , 



L gritty in places at the base (4 a). ) 



3 b. Greensand, yellowish and rather clayey towards the top ; clean, and~) 

 dark sage-green below ; full of worn and broken bits of shell | 

 in the lower 6 inches, but hardly a\\\ fossils in the upper part. }■ 3 

 ' Belemnites minimus,' ' Inoceramus concentricus,' small 'Ostrea,' | 

 ' Cidaris ' spines, teeth of fishes, etc. (See p. 49.) J 



The bed thins out to about 9 inches as we go 7 yards northwards; 

 and at the next working-place, a few yards farther north, has 

 entirely died out ; but at the base of the Gault there is a dark 

 claj'^-band, full of small black pebbles (lydite, etc.), about 6 inches 

 thick, resting on — 

 3, Irregular floor of iron-grit, worn on the knobs, with breccia of 



ironstone, etc. in the hollows. 

 2&1. Lower beds as in the preceding paper, not studied in detail. 



