Excursion to Erith. Saturday, March 30th, 1912 - Geologists' Association excursion

Geologists' Association Circular No. 142. Session 1911–1912. p.4-6

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Excursion to Erith. Saturday, March 30th, 1912. (Transcription from GA Circular No. 142. Session 1911–1912. p.4-6)

DIRECTORS: R. H. CHANDLER AND A. L. Luwat, F.G.S.

EXCURSION SECRETARY: MISS E. CADMORE, 4, Ulundi Road, Blackheath.

Meet the Excursion Secretary at Charing Cross (under the clock), not later than 1.15 p.m , to obtain cheap return tickets, 1s, 8d. Leave Charing Cross 1.32 p.m. by train due at Erith 2,30 p.m. Meet the Directors at Frith 2.30 p.m.

Examine (by permission of Messrs. Parish, Ltd.), a fine section of the Lower Tertiaries (Thanet Sand, Woolwich Beds and Blackheath Beds), in the great pit at Frith. Chalk is shown on the floor of the pit, and the base of the London Clay was shown, until recently, on the south face of the pit; the section therefore includes the whole Lower London. Tertiary group. The junctions between the various members are well exposed. A great feature of the pit at the present time is the contrast between the eastern and southern faces; on the former up to 40 ft. of Woolwich Beds are seen beneath a mere trace of Blackheath Beds, while on the south face a thick Blackheath Pebble-bed, charring strong diagonal bedding, rests on the bottom bed or green loam of the Woolwich series. The Woolwich Beds include both mottled clays and Cyrena shell-beds.

Sections in ballast pit near Erith Railway Station.

Nos. 1, 2, and 3, South side, No. 4 West side.—R. H. Chandler.

Blackheath Beds

a = Soil and "trail," 1–7 ft.

b = Evenly-bedded clean sands, brown and yellow, resting in hollows of the pebble. beds, 7 ft.

b1 = Dark brown clayey sand, resting in hollows of the pebble-beds, 10 ft

d = Strongly false-bedded pebble-beds in sandy matrix, resting erosively in the Woolwich Beds, 27 ft.

Woolwich and Reading Beds

e = Brown shell clays, Cyrena, etc., 14 ft.

e1= Pale-coloured clays, unfossiliferous, 4 ft. 6 in.

f = Light-brown coated flint pebbles in sandy matrix, 3 ft.

g = Green clayey sand.18ft

g1= Pale yellow sand, only distinguishable from Thanet Sand by the presence of pebble-bed "j," 12ft.

g11 = Clean pale-buff sand (almost white), 16 ft.

h = Green clayey sand with ferruginous concretions, 3 ft.

j = Black-coated flint pebbles in sandy matrix, splashed into Thanet Sand below and scattered into the sandy Woolwich Beds above, 6 in. to 2 ft. Sometimes divisible into two beds separated by sand, as 2 and 4 (6 ft. thick in section 2). Resting erosively on the Thanet Sand in section 1.

T.S.=Thanet Sand, 40–50 ft. to Chalk.

From the Ballast Pit the party will walk to the brick-earth pits in the Middle Terrace (Crayford) River Drift, near North End. Since the Association last visited these pits in 1905 they have been much enlarged and excellent sections are shown. Some Pleistocene shells and palmolithic flakes may be obtained, but they are net common. If time permit the Drift in both Stoneham's and Ratter's pits will be examined.

Return to Erith for tea.

Total walking distance 4 miles.

Train leaves Erich 7.5 p.m, and arrives at Charing Cross 8.9 p.m.

REFERENCES.

Geological Map, 1-in. scale. London District (Drift Edition). Sheet 4. 1s. 6d

1889. WHITAKER, W.—"Geology of London," vol. i. Mem. Geol. Survey.

1905. SALTER, DR. A. E.—"Superficial Deposits of Central and Parts of Southern England." Proc. Geol. Assoc., vol. xix, pp. 1–56.

1905. LEACH, A. L.—"Excursion to Erith and Crayford." Proc. Geol. Assoc., vol. xix (1905), p. 137.

1908. LEACH, A. L.—"Excursion to Charlton and Erith." Proc. Geol. Assoc., vol xx (1908), p. 505.

Images

Excursion to Erith, March 30th 1912

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  Section at south side of the Ballast Pit, Erith.
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  Section at the west end of the Ballast Pit, Erith.
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  Sections of Thanet Sand at south side of Ballast Pit, near Erith Railway Station.
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  Sections of Thanet Sand at south side of Ballast Pit, near Erith Railway Station.
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  Norris's Pit. Brickearth resting upon an eroded slope of Chalk and Thanet Sand.
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  Norris's Pit. Brickearth on Chalk.
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  South side, Ballast Pit, near Erith Station. Blackheath Pebble Beds in sandy matrix resting erosively on the Woolwich Beds.
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  Ballast Pit, Erith. Blackheath pebbles.

List of photographs

Excursion to Erith, March 30th 1912

Page 81	P805488	Section at south side of the Ballast Pit, Erith. Excursion to Erith, March 30th 1912. Added note: Thanet Sand; Woolwich and Reading; Blackheath beds. [Bottom to top.].
Page 81	P805489	Section at the west end of the Ballast Pit, Erith. Excursion to Erith, March 30th 1912. Added note: Thanet Sand; Woolwich and Reading; Blackheath beds; Soil and hillwash with possible base of London Clay. [Bottom to top.].
Page 81	P805490	Sections of Thanet Sand at south side of Ballast Pit, near Erith Railway Station. Excursion to Erith, March 30th 1912.
Page 81	P805491	Sections of Thanet Sand at south side of Ballast Pit, near Erith Railway Station. Excursion to Erith, March 30th 1912. Added note; Thanet Sand, 40 to 50 feet in thickness, resting on chalk; Woolwich and Reading; Blackheath beds. [Bottom to top.].
Page 83	P805492	Norris's Pit. Brickearth resting upon an eroded slope of Chalk and Thanet Sand. Excursion to Erith, March 30th 1912. Added note; Chalk; Thanet Sand; Brickearth. [Bottom to top.].
Page 83	P805493	Norris's Pit. Brickearth on Chalk. Excursion to Erith, March 30th 1912.
Page 83	P805494	South side, Ballast Pit, near Erith Station. Blackheath Pebble Beds in sandy matrix resting erosively on the Woolwich Beds. Excursion to Erith, March 30th 1912.
Page 83	P805495	Ballast Pit, Erith. Blackheath pebbles. Excursion to Erith, March 30th 1912. [Specimens.].