If. J. «. S. vol. xliii.J 



rig. 1. — xionzonrat section from w ellmgton Uollege to Wokingham, Berks. 



[lv /live p. qoo. 



/ ■ 



Cut -f 1U0 B 



(O.D 



ft 



.No. X 



=^-No. 4. 

 Ho. 5. 

 Nos. 7 fe 8. 

 •Nob. 9 & 10. 



100 



> London Clay, 



II ilea i 



i 



i 



l 



Zinc of Railway : the gradients kindly furnished by the Company's Chief Engineer, F. Brady, Esq. 



* Level of mouth of Wellington College Well (287 O.D.), ^ mile E.N.E. of this point. The reference-numbers indicate the corresponding beds in that well 

 (see Q. J. G. S. vol. xli. p. 494). B. Latham, Esq , O.E., F.G.S., has kindly furnished exact levels for the vicinity of Wellington College. 

 Note. — For the Wokingham Outlier the line of section is taken a short distance east of the railway. 

 d. Drift-gravels. 

 /No. 3. Pebble-bed. 



No. 4. Irregularly stratified sandy loam, with green grains, thin seams of white clay, and irony conuretions. 

 | No. 5. Interlaminated clay -seams and green sands. 

 Middle Bagshot ■< [No. 6. In the well-section and in the neighbouring brick-fields a bed of flint-pebbles ; not proved on the railway, beyond a mere line of 



pebbles.] 



| Nos. 7 & 8. Green earths and sands. 



( Nos. 9 & 10. Mixed clays, loams, and coarse ferruginous sands [basement-beds of the middle group]. 

 Lower Bagshot S^ os - H - 13. Fine quartz-sand (in the well-sections carbonaceous, with lignite and pyrites nodules; dark grey-green), with little or no iron 

 \ where cleaned by slow moist oxidation. No. 13=a fine sandy clay [passage bed]. 



London Clat. 



Tig. 2. — Horizontal Section from the River Loddon to Ascot Race-course. 



Ch a I A 



L Upper Bagsbot Sands. 4. Lower Bagshot fine quartz-sand (a few feet only in the outliers ; in some places wanting). 



2. Pebble-beds (occurring at two distinct horizons at Bracknell). 6. Passage-bed. 



3. Middle Bagshot Clays and ferruginous loams (probably = Nob. 9 & 10 of fig. 1). O. Chalk, proved in the deep wells at Bearwood, Wokingham, and Ascot. 



We. — The erosion of the London Clay benedth the Bagshot outliers is known from minor sections ; the boundary in the Ascot region (indicated by the broken line) is inferred. 



