368 MB. H. B. WOODWAED ON DISTUEBANCES [Allg. I903, 



No doubt the pit has been considerably enlarged since that 

 section was recorded, and other features have been made manifest ; 

 but I cannot help thinking that the illustration drawn by Penning 

 was what the Rev. J. F. Blake would call an ' interpretation-section,' 

 rather than an actual representation, because the picture does not 

 strictly accord with the explanation : for instance, the scattered 

 flints in the Upper Chalk are shown as a continuous band of 

 nodules, in the midst of even bands of Chalk. 



(4) North of Reed, east of the main road., about 2 miles 

 from Royston. [This chalk-pit is 500 feet above sea-level.] 



Here, at first sight, we seem clearly to have an ordinary gentle 

 anticlinal disturbance. 



The beds appear to arch over slightly towards the south, and 

 there is a small dislocation. A thin clayey seam occurs in place 

 towards the base of the pit, and in the Chalk below is an irregular 



Fig. 7. — Section north of Heed. 

 N. 



— — -. ^ y— 



*• 





s. 



Boulder. c •* «*^-^^' ** „ * J^ " ■ — «' 



-Clay • -^ ^ • ^^ * ., , - 



' « ' +' st? ./< 



<v 



\ 



N 

 > 

 \ 



s 

 ~" it ' — \ 



j&sP ■ Fhn \ s Clayey 



6- \\t^" irregular seam 

 pC c^C>^ 







Clay- 

 gall 



[Scales, vertical & horizontal : 1 inch = 44 feet.] 



gall of brown clay. Regular bands of flint, both nodular and tabular, 

 appear at higher horizons dipping northward. 



The lowermost of the bands becomes broken towards the north. 

 At some little distance above it is a band of shattered Chalk- 

 Rock, the mass for 3 or 4 feet in thickness having the ap- 

 pearance of a chalk-breccia, or of broken beds. Still higher up 

 there is a thin continuous layer of tabular flint, showing slight 

 irregularities. 



Boulder-Clay occurs at the northern end of the pit ; and both 

 here and at Smith's End, Messrs. Penning & Jukes-Browne observed 

 that this drift rested ' on a surface of the beds nearly parallel to 

 their stratification,' as if ' the disturbing force had acted on the 

 beds in post-Glacial times.' l 



1 'Geology of the Neighbourhood of Cambridge ' Mem. Geol. Surv. (1881) 

 p. 67. 



