Excursion to the Pleistocene River Drift at Crayford, and some swallow holes at Barnhurst. Saturday, June 28th, 1913

Geologists' Association Circular No. 156. Session 1912-1913. p.14-15

DIRECTOR: R. H. CHANDLER.

EXCURSION SECRETARY: Miss E. PEARSE, 3, Bessborough Mansions, Westminster, S.W.

Leave Cannon Street Station 147 p.m.. reaching Siade's Green at 2.43 p.m.

Meet Excursion Secretary under clock in station not later than 1.30 p.m. Special return fare 1s.. 8d. Meet Director.at Slade's Green Station.

One of the objects of this excursion is to study the gravel at the base of the Brickearth and to note its junction with the Alluvium. It is suggested that what has been called the Fourth Terrace is, in this district, only an extension of the base gravel belonging to the Crayford (or Second) Terrace.

Figure 4 Diagram from a photograph of prehistoric "hearth " in Norris' Pit.—R. H. Chandler.

1. Soil and subsoil.

2. Burnt flints ("pot-boilers"), charcoal, and black earth.

3. Burnt clay.

4. False-bedded sand and gravel of Crayford Terrace.

All the sections indicated by vertical lines in the diagram (Figure 3) are still accessible and ought to give a clear idea of the formation of the Crayford Terrace. Some fine sections of "Trail" are showing, and it is seen to cut off the Upper Brick-earth, the "Cyrena. (Corbicula) Bed," and then the lower Brick earth, until it rests upon the gravel. This "Trail" still awaits a satisfactory explanation of its formation.

From Slade's Green Station the party will walk to the end of the gravel spit (see Figure 3) and there see the relative levels of the alluvium and the gravel belong- ing to the Brickearth Series. On the return notice Howbury (a. moated farmhouse, of which mention is made in Domesday Book—the present building probably dates from the early 18th Century) ; walk through the adjoining gravel pit (where Mr. C. T. Gatty obtained the supposed pygmy flint implements described in Westminster Gazette for April 24th and 25th, 1912) and cross a tongue of the marsh into all House Farm Gravel pit. Here, by kind permission of Mr. C. H. Norris, the prehistoric "hearth" shown in Figure 4 will be preserved till the visit of the Association. The gravel in Wall House Farm pit contains abundant chalk pebbles towards the base, and, in places, passes into rubbly chalk containing little gravel. Roman and British pottery has been found in removing the soil. Visit Furner's new pit, showing the "Trail" finely contorted, and in Rutter's pit notice the beginning of the" Cyrena (Corbicula) fluminalis Bed." In the new part of Rutter's pit. the Director has obtained several "cores," from which flakes have been struck by palaeolithic man, and also some flakes that fit together, thus proving the existence of a palteolithic flint implement factory on this site. These cores, flakes, and implements will be exhibited, and their relation to the implements from neighbouring beds pointed out. The usual mollus.ca and mammal hones and teeth wilt be found. Walk to Norris's pit and see the Pleistocene River bank against which. the Brick-earths lie.

Tea at "The Harrow Inn," North End, Erith (plain tea 1s., meat tea 1s. 6d.). After tea walk to Perry Street (passing the large pit in which Spurrell found the first palaeolithic flaking floor discovered in this country) and through Perry Street Farm to Barnhurst. The upper part of the valley followed by the railway from Stacie's Green to Barnhurst (known as "Courtleet Bottom") is remarkable for the existence of seven swallow holes within a distance of half a mile. Well marked channels run into some of the holes, and recently water was seen disappearing down one of them, although all are now dry. A roadside section shows the position in which these swallow-holes occur in the Tertiary Beds.

Arrive at Barnhurst Station in time for 7.36 train, reaching Cannon Street 8.26.

Many sections are worth photographing.

Total walking- distance, four to five miles.

REFERENCES.

Ordnance Survey Map, 1 inch, Sheet 271. 6 inch, Kent, Sheet 111 S.W.

Geological Survey Map, 1 inch, London District (Drift Edn.), Sheet 4.

1869. TYLOR, A.—"On Quaternary Gravels". Quart. Journ. Geol. Soc., vol. xxv, p. 57.

1880. SPURRELL, F. C. J.—"On the Discovery of the Place where PaIaeolithic Implements were made at Crayford." Quart. Journ. Soc.,vol.xxxvi, p. 544.

1886. SPURRELL, F. C. J. —"A sketch of the History of the Rivers and Denudation of West Kent, etc."Report of W. Kent Nat. Hist. Soc., p. 1.

1889. SPURRELL, F. C. J.—"On the Estuary of the Thames and its Alluvium." Proc. Geol. Assoc., vol. xi, p. 210.

1889. WHITAKER, W.—"Geology of London." Vol. 1. Memoirs Geol. Survey.

1905. HINTON, M. A. C., AND A. S. KENNARD,—"The Relative Ages of the Stone Implements of the Lower Thames Valley," Proc. Geol. Assoc., vol. xix, p. 76.

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

1909. WOODWARD, H. B.—"The Geology of the London District?' .Memoirs Geol. Survey.

1912. CHANDLER., R. H., AND A. L. LEACH.—"Report of an Excursion to the Lower Tertiary Section and the Pleistocene River Drifts near Erith." Proc. Geol. Assoc., vol. xxiii, p. 183.

Images

Excursion to Crayford, June 20th 1913

Norris's Pit.
Norris's Pit.

List of photographs

Excursion to Crayford, June 20th 1913

Page 61	P804613	Excursion to Crayford, June 20th 1913.
Page 61	P804614	Excursion to Crayford, June 20th 1913.
Page 61	P804615	Norris's Pit. Pleistocene river bank against which the Brickearths lie. Excursion to Crayford, June 20th 1913. Added note: Chalk; Brickearth; river bank. [Bottom to top.]
Page 61	P804616	Norris's Pit. Pleistocene river bank against which the Brickearths lie. Excursion to Crayford, June 20th 1913. Added note: Chalk; Brickearth. [Bottom to top.].

Excursion to the Pleistocene River Drift at Crayford, and some swallow holes at Barnhurst. Saturday, June 28th, 1913 - Geologists' Association excursion

Contents

Geologists' Association Circular No. 156. Session 1912-1913. p.14-15