Excursion to Henley and Watlington. Saturday, July 13th 1912 - Geologists' Association excursion

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Geologists' Association Circular No. 146. Session 1911–1912. p.3-4[edit]

Excursion to Henley and Watlington. Saturday, July 13th 1912. (Transcription from GA Circular No. 146. Session 1911–1912. p.3-4)[edit]

DIRECTOR: H. L. HAWKINS, M.Sc., F.G.S.

EXCURSION SECRETARY: MARK WINKS, 47, Upper Clapton Road, N.E.

Leave Paddington 50.40 a.m. ; due at Henley 11.58. Meet Mr. Wilks in the Booking Office not later than tool. Cheap return fare 40. 6d. each.

Drive from Henley Station along the valley of the Assendon Spring to Stonor. Cost of drive 1s. 6d. each. Members should notify Secretary in order to ensure room on conveyances.

Walk up the ridge road N. of Pishill Bottom. The sides of the road afford an almost continuous section of Chalk. At first (No. 1 in the section) the chief fossils are thin-shelled Inocerami and occasional Terabratulinae. At about 440 ft. O.D. a shallow excavation (2) shows Chalk Rock. The charactelistic fossils are not uncommon. Beyond the short platform caused by the outcrop of the Rock the road cuttings show Chalk with many tabular, and a few nodular, flint-bands, with iron-stained Sponge casts (3). Echinocorys, uncommon in the higher parts. Probably both the H. planus and M. cor-testudinarium zone are represented. From Hollandridge Farm (4) to the crest of the escarpment the route traverses beech-woods growing on Clay with Flints. This is very thick and ferruginous. Shallow sections will be seen, and in addition certain concretionary ironstone blocks derived from it.

From Christmas Common (789 ft. O.D.) an extensive view of the Chiltern Hills and Upper Thames Valley may be seen.

Ou Wallington Hill it may be possible to see expos of cor-anguinum Chalk (6) and the Chalk Rock (7) in the drainage trenches. Both were visible in, May.

The large chalk pit near the foot of the hill (8) is rich in the fossils typical of the R. cuvieri-zone. R. cuvieri and Conulus subrotundus are the most abundant fossils except for Inoceramus.

Tea at the Hare and Hounds, Wallington. Tea with eggs, 1s,; meat tea, 1s. 9d.

Return train leaves Watlington 6.59 p.m., reaching Paddington 9.0.

Walking distance about 7 miles.

REFERENCES.

Geological Survey Map, 1 in. Sheet 254.

1906. JUKES-BROWNE.—"The Clay with Flints; its Origin and Distribution." Quart. Journ. Geol. Soc.., lxii, p. 132.

1908. JUKES-BROWNE AND OSBORNE "The Geology of the country around Henley-on-Thames and Wallingford." Mem. Geol. Surv.

Images[edit]

List of photographs[edit]

Excursion to Henley, July 13th 1912[edit]

Page 113 P805550 Chalk sections on the Ridge Road to Hollandridge, at 550 OD. Zone of Micraster cortestudinarium. Tabular flint passing obliquely and nearly vertically along joints and sliding planes. Excursion to Henley, July 13th 1912.
Page 113 P805551 Chalk sections on the Ridge Road to Hollandridge, at 550 OD. Zone of Micraster cortestudinarium. Excursion to Henley, July 13th 1912. The lower band consisting of nodular flints are mostly branching forms of sponges encased in flint, but the upper band of tabular flint contains no fossils. Added note: Nodular flints; Tabular flints. [Bottom to top.].
Page 113 P805552 Chalk sections on the Ridge Road to Hollandridge, at 550 OD. Zone of Micraster cortestudinarium. Excursion to Henley, July 13th 1912. For the most part these tabular flints seem to follow the bedding planes but in this section they are all double, the two halves enclosing a layer of white powder of varying thickness largely composed of long sponge spicules. These comparatively horizontal layers of flint separate and converge irregularly so that the amount of Chalk included between two 'tabulars' may be over a foot in one place and almost touching in others.
Page 113 P805553 Chalk sections on the Ridge Road to Hollandridge, at 550 OD. Zone of Micraster cortestudinarium. Excursion to Henley, July 13th 1912. For the most part these tabular flints seem to follow the bedding planes but in this section they are all double, the two halves enclosing a layer of white powder of varying thickness largely composed of long sponge spicules. These comparatively horizontal layers of flint separate and converge irregularly so that the amount of Chalk included between two 'tabulars' may be over a foot in one place and almost touching in others.
Page 115 P805554 Wattington. Chalk section showing faulting and pipes at 450 feet OD. Zone of Rhynchonella cuvieri. Excursion to Henley, July 13th 1912.
Page 115 P805555 Wattington. Chalk section showing faulting and pipes at 450 feet OD. Zone of Rhynchonella cuvieri. Excursion to Henley, July 13th 1912.
Page 115 P805556 Wattington. Wedge shaped jointing in Chalk. Excursion to Henley, July 13th 1912.
Page 115 P805557 Wattington. Wedge shaped jointing in Chalk. Excursion to Henley, July 13th 1912.