part 1] aAULT and lower greensaisd neae leightojvt. 



33 



S.W. 



Section at the s o u t li - w e s t e r n comer of S p i n n e }'■ pit, 

 Grovebury; August 13th, 190i. Surface, 300 feet O.D. 



ZY 



4 

 4. 



about 2 



about 3 



y about 3 



to 1 



Thickness in feet. 

 Top soil, clayey, with flint and quavtzite-pebbles, merging") , 



down into — ) 



Disturbed and rearranged Gault cla}^ with an occasional 7 

 pebble. ) 



Stiff blue Gault, somewhat disturbed, with a few pale-coated 

 phospbatic nodules, dark internally, mostly of tubular 

 shape ; passing down into — 



3b. Rust}^ and greenish glauconitic loam streaked with sai:d3'and"^ 

 clayej'- layers ; sprinkled with polished quartz-grains, 

 lydites, and hard flaky bits of ironstone, abundantly towards 

 tbe base; scattered phospbatic nodules, rather plentiful, 

 becoming a fairl}^ continuous band in the lower part, and 

 there very grittj^ and lydite-shot ; also, near the base, an 

 occasional iron-crusted boxstone with the outside polished 

 and worn. One of the phosijhatic nodules, close to the 

 base, held an imperfect cast of a large smooth sharp-keeled 

 discoid ammonite; another, traces of a crustacean. J 



? 3a Rusty coarse sand, with large calcareous concretions, a few'^ 



ov bits of ironstone, and traces of ferruginous boxstones ; f 



lb. forms the top of the Sands, but lies parallel to the beds X 

 above, and across the current-bedding below^ J 



1. Coarse sharp Sand, rich coft'ee-coloured at the top, but grey 

 below, with dark chocolate-coloured streaks bringing out 

 magnificent cross-bedding and other structures. 



Similar sections were seen in 1906 and 1908 in the more easterly 

 working of the pit; but the cover of Grault was then thinner, and 

 no new features were observed. A year or two later the grittj?" 

 phospbatic nodules began to show in fair numbers, in the detrital 

 top-soil of the next pit on the west (' Eailway ' or ' Eirbank's '), 

 along a straight working-face of nearly 200 yards ; and by 1912 

 this section shoAved a foot or two of weathered gritty clay con- 

 taining nodules of the same kind, beneath the soil. By repeated 

 search I collected from the nodules a fair number of fossils in the 

 form of casts ; but they were fewer here than in the sections 

 exposed later in Pratt's pit (p. 35) and Chamberlain Barn pit 

 (p. 30). The working-face has since been cut back for another 

 50 3^ards or so, and showed in 1920 the subjoined section (fig. 17) 

 in a bay at the south-eastern end, where the Gault is thickest. 



Fig. 



17.— Section of tlie soutli-eastern corner of ^ Haihvay ' pit 

 adjacent to Grovehury JBriclcworlcs (adjoining the nortli- 

 ivestern corner of old Spinney ]?it) ; Septeonher 29th, 1920. 

 Surface, 300 feet O.D. 



N.E. 





Z — -T - o ^. 



o \.* - 



o — - 



10 15 feet 



Scale' Vertical and Horizontal 



Q. J. a. S. No. 309. 



D 



