Excursion to Northwood and Croxley Green. Saturday, July 24th, 1909 - Geologists' Association excursion
Geologists' Association Circular No. 112 Session 1908–1909
Excursion to Northwood and Croxley Green. Saturday, July 24th, 1909. (Transcription from GA Circular No. 108 Session 1908 1909 p.2)
DIRECTOR : H. KIDNER, F.G.S.
EXCURSION SECRETARY A. C. YOUNG, 17, Vicar's Hill, Lewisham, S.E.
Leave Marylebone (Great Central) 2.15, arrive Northwood 2.42. Special return tickets to Northwood, 1s. 3d. At the Northwood Brickfield examine sections in the Reading series and Basement Bed of the London Clay. In the lower part of the workings is fine pale sand, with Is or 16 feet of mottled clay ; in the upper part, sandy clay 55 feet (Basement Bed), a pebble bed 6 inches, and 3 feet of brown clay. At Northwood take ordinary return tickets to Rickmansworth. Leave Northwood 3.40, arrive Rickmansworth 3.47 ; walk one mile to the Croxley Gravel Pits to examine an Outlier of the Woolwich and Reading Beds, recently uncovered in digging the gravel. The section shows, in descending order, greenish sandy clay 15 feet, pebbles with grey sand 2 feet, pebbles with brown sand (red in parts) 1 foot, brown sand with scattered pebbles 6 feet. A few quartz pebbles occur in the pebble bed. The Reading Section extends several yards, and is overlain with 16 to 18 feet of Pleistocene gravel. Return to Rickmansworth through Croxley Green, where Sir Hugh Beevor and Dr. S. Oddie will exhibit their collection of between 200 and 300 flint implements ; and Dr. Oddie will show a large Sarsen removed from the Croxley Pits. Plain tea, 9d., with eggs, is., at the George Hotel, Rickmansworth, at 6.15. The Herts Natural History Society will take part in the excursion. Total walking distance, 3 miles. Return from Rickmansworth 7.15, arrive Marylebone 7.48.
Geological Survey Map, London District (Drift), Sheet 1, 1s. 6d.
1889 WHITAKER, W.—"Geology of London," Mem Geol. Survey, vol. i.
1907. HOPKINSON, J., and KIDNER, H.—" Excursion to Bushey and Croxley Green, "Proc. Geol. Assoc., vol. xx, p. 94.
List of photographs
Excursion to Northwood and Croxley Green, July 24th 1909
|Page 77||P805346||Northwood Company's Buck pit. Section in lower part of London Clay. Excursion to Northwood and Croxley Green, July 24th 1909. Added note: Floor of pit, tenacious marly clay 2 ft thick forming the top of the Reading Beds and passing into mottled clay below; Sandy clay Basement bed, calcareous with many fossiliferous nodules, 5ft 6 inches thick; Pebble Bed; London Clay 3 ft. [Bottom to top.].|
|Page 77||P805347||Gravel pits, Long Valley Wood, Rickmansworth. 200 ft OD. Excursion to Northwood and Croxley Green, July 24th 1909.|
|Page 77||P805348||Outlier of Reading Beds uncovered in digging away the gravel extending horizontally for upwards of 100 ft. Excursion to Northwood and Croxley Green, July 24th 1909. Added note: Clay and pebbles proved below from 2 to 3 ft resting on Chalk; Bedded black and grey pebbles 6 ft; Greenish sandy clay 1 ft. 6 inches [Bottom to top.].|