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XXXI. 
NOTES ON THE GEOLOGY OF WESTERN HERTFORDSHIRE. 
By Henry Kidner,' F.G-.S. 
Read at Watford , 27th March, 1911. 
Heading Outlier at Croxley .—The gravel-pits in Long Yalley 
Wood, Croxley, were visited by Mr. G-. J. Roberts and the writer 
last April, when a very fine section of the Reading Beds was 
seen. They occur here as an outlier overlaid by Pleistocene 
gravel. The section showed, in descending order : G-reen sandy 
clay, 1 ft. 6 ins. ; bed of flint-pebbles in a matrix of greenish 
sandy clay above and brown sand below, 3 ft.; green, brown, 
and reddish sand with scattered flint-pebbles in places, 6 ft. ; 
total 10 ft. 6 ins. The section was seen to extend as described 
about 50 yards, approximately east and west, but the sand could 
be traced for a further 50 yards, proving a horizontal extension 
of the outlier for at least 100 yards. The floor of the gravel-pit 
was approximately along the top of the sand, and the sand was 
exposed in places by excavations below the floor of the pit. 
Heaps of the sand, which had been dug out of these, were seen. 
About 14 or 15 ft. of gravel overlaid the outlier. 
Brick-field at Hill Hnd, St. Albans .—With the permission of 
the proprietor, the writer visited some large pits in a brick-field 
at this place, where interesting beds of considerable thickness 
are to be seen. One section showed about 18 feet of beds, 
including 10 feet of stratified gravel, with brick-earth and clay 
full of flints and flint-pebbles above. In another part of the 
brick-field a section showed about 10 feet of boulder-clay at the 
top, overlaying six or seven alternating beds of sand, gravel, and 
loam of varying thickness, the whole making a total thickness of 
35 feet or more. 
Trans. Hertfordshire Nat. Hist. Soc., Vol. XIV, Tart //., July, 1912. 
