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Excursion to netley heath and newlands corner
EXCURSION TO NETLEY HEATH AND NEWLANDS CORNER. SATURDAY, AUGUST 11TH,
1900.
Director: W. P. D. STEBBING, F G.S. Excursion Secretary: H. A. HINTON, B.Sc., F.G.S. (Report 0)' THE DIRECTOR.)
THE chief object of the excursion was to examine the gravel. sands, and ironstone at Netley Heath, to prove the fossiliferous character of the ironstone and to show the similarity of the beds to those occurring at points farther eastward on the North Downs. The party assembled at Gomshall Station, and walked by way of Colekitchen Farm to Netley Heath, traversing the outcrop of the Gault and Upper Greensand. A fine section in the Folkestone Beds was seen outside the station, and another section at the top of these sands was examined j also road sections in the Gault, Upper Greensand, and base of the Middle Chalk were noted in passing. Netley Heath consists of a tract of ground with a northerly slope, mainly covered with heather. The sands and ironstones are shown by a red colour on Sheet 8 of the Geological Survey Map, and extend from a level of about 600 feet O.D. almost au the top of the North Downs (as at Headley Heath) to a level of about 570 feet O.D. This patch of sand and ironstone forms one of a series which is found along the top of the North Downs from Netley Heath to Paddlesworth, north of Folkestone. The fossiliferous pipes at Lenham, range from 500 to 620 feet O.D., and the sands on Headley Heath occur at 628 feet O.D. But although of a far more recent age than the Eocene outliers, which are often in close proximity, these sands occur at much the same level or even below them. This is undoubtedly due to their porous nature, which allows water to pass through and dissolve the chalk below. The attention of geologists was first drawn to this series by Prestwich in 1857 (Quart. Journ. Geoi. Soc., vol. xiv, p. 322), and details of all the patches will be found in our President's Memoir on the London Basin (Whitaker, Mem. Geol. Survey, vol. iv, 1872, pp. 339-34 2 ) . As early as 1854 fossils were found in one of these patches at Lenham, in Kent, but their evidence as to the age of the sands was considered doubtful, although Prestwich assigned them to the Crag. In 1886 Mr. Clement Reid made a careful investigation of the deposit at Lenham and its fossils, and satisfactorily proved the deposit to be of Pliocene age (Nature. PROC, GEOL.
Assoc.,
VOL. XVI, PART 10, NOVEMBER, 19oo.J
EXCURSION TO NETLEY HEATH AND NEWLANDS CORNER.
525
vol. xxxiv, p. 34 I). A full account of Mr. Reid's work will be found in his Memoir on the Pliocene Deposits of Great Britain, 1890 (Man. Ceo!. Survey). At page 48 he remarks: "Westward, towards Merstham and Guildford, some of the outliers mapped by the Survey may really be Pliocene as suggested by Prof. Prestwich, but at present there is such an entire absence of positive evidence in favour of this view that it is needless to describe them." This sentence is quoted to show the great interest which attaches to the imperfect fossils found now apparently for the first time at Netley Heath. The patch in which they are found is not mapped as Eocene or Pliocene, but as of doubtful age. The fossils are in the form of casts in af erruginous sandy grit with occasional flint pebbles. The grit much resembles the ferruginous sandstone of the Folkestone Beds, but the presence of the flint pebbles is sufficient distinction. Fragments of fossils referable to the genera Modio!a, and possibly Cyprina, were found by members during the excursion, and fragments of Nassa, Trochus, Cardium, Pedunculus, Tellina, and Thracia have since been found, but in such a poor state of preservation that they cannot be specifically determined. These genera indicate beds of a marine origin, and although they do not enable us to correlate these deposits with those at Lenham with certainty, I am inclined to think that the beds will prove to be of the same age. AlI the above genera except frfodiola have been found at Lenharn, where, on the visit of the Geologists' Association in 1892, 31 species of fossils belonging to 27 genera were obtained. It was remarked by members who had visited Lenham, that the mode of occurence of the fossils and the appearance of the matrix greatly resemble the conditions obtaining at Lenham, The following sections were visited: A sand-pit on the east of a road from Gomshall to East Horsley, showing about 10 feet of yellow and bleached sand, above the sand are some patches of mottled clay and gravel consisting almost wholIy of rolIed fragments of chert and ironstone from the Lower Greensand. Level, about 570 feet. 2. A small pit about 5 feet deep, at a level of rather over 600 feet; the section shows highly ferruginous yellow sand with a few small pebbles and much concretionary iron ore, with chert and patches of rolled flints above. The fossils came from this pit. 3. A sand-pit half-a-mile west of the first pit, showing about I Z feet of yellow sand with a few small pebbles, and in one place a patch of small pebbles above the sand. Level about 600 feet. I.
There is a fourth section on the Heath rather lower than the others, which was not visited. This pit contains a mixture of
LONG EXCURSION TO KESWICK
sand and rolled flints of all sizes, and is exactly similar to one seen on Headley Heath in 1895, at about the same level. The Director remarked that the difference in these three sections on Netley Heath is surprising considering their short -distance apart; but if we suppose that they were formed on a submerged reef away from the coast line-which is Mr. Reid's theory-those portions of the reef near the sea-level would be most affected by the action of the sea, which would prevent shells from accumulating on those portions, and which would have a rounding action upon any loose stones; a state of things which might explain section 1. Leaving Netley Heath, the members followed the track along the top of the North Downs to Newlands Corner, and visited the extensive gravel workings there at about 500 feet O.D. The gravel, which otherwise is similar to that which occurs in most of the sections on Headley Heath, is characterised by the large size of the flints of which it is chiefly composed. Mr. Monckton's explanation of it is that it is probably a very old river gravel, but no doubt newer than the sands and ironstone of Netley Heath. Leaving these sections, the party made their way to Chilworth for tea. After the Director's reply to a most cordial vote of thanks, the geologists returned by the 7.56 train to London. REFERENCES. Geelogical Survey Map, Sheet 8 (Drift Edition). Or dnance Survey i\lap, New Series, Sheet 285, rs. 1862. "V. 'VHITAKEI'.-" On the Western End of the London Basin, etc.," Quart, Journ. Ceo]. Soc., \"01. xviii, p. 273. 188j. H. H. FHEl\'CH.-" Excursion to Con.shall, Netley Heath and Clandon," Proc. Ceol. Assoc .. \"01. x, p. r82.
LONG EXCURSION TO KESWICK. lVloNDAV,
AUGUST
Director:
aoth,
JOHN
to
SATURDAY,
AUGUST
25th,
r90o.
E. MARR, M.A., F.R.S., F.G.S.
Excursion Secretary: FREDERICK i\1EESON.
(RejJort "" THE DIRECTOR.) [PLATES XIII, XIV.]
fifty and sixty members of the Association and their friends assembled at E.. eswick, making the Park Hotel their headquarters. In addition to the official programme, unofficial excursions were conducted on days preceding and succeeding those announced in the official circular, under the leadership of Mr. J. Postlethwaite, F.G S. lIfo71day, Au,!;ust 20tlt.-The day was mainly devoted to an examination of the characters of the Falcon Crag and Bleaberry
BETWEEN
PROC. GEOL. Assoc., VOL. XVI, PART 10, l'\OVEMBER, 1900.J
1900.
Director: W. P. D. STEBBING, F G.S. Excursion Secretary: H. A. HINTON, B.Sc., F.G.S. (Report 0)' THE DIRECTOR.)
THE chief object of the excursion was to examine the gravel. sands, and ironstone at Netley Heath, to prove the fossiliferous character of the ironstone and to show the similarity of the beds to those occurring at points farther eastward on the North Downs. The party assembled at Gomshall Station, and walked by way of Colekitchen Farm to Netley Heath, traversing the outcrop of the Gault and Upper Greensand. A fine section in the Folkestone Beds was seen outside the station, and another section at the top of these sands was examined j also road sections in the Gault, Upper Greensand, and base of the Middle Chalk were noted in passing. Netley Heath consists of a tract of ground with a northerly slope, mainly covered with heather. The sands and ironstones are shown by a red colour on Sheet 8 of the Geological Survey Map, and extend from a level of about 600 feet O.D. almost au the top of the North Downs (as at Headley Heath) to a level of about 570 feet O.D. This patch of sand and ironstone forms one of a series which is found along the top of the North Downs from Netley Heath to Paddlesworth, north of Folkestone. The fossiliferous pipes at Lenham, range from 500 to 620 feet O.D., and the sands on Headley Heath occur at 628 feet O.D. But although of a far more recent age than the Eocene outliers, which are often in close proximity, these sands occur at much the same level or even below them. This is undoubtedly due to their porous nature, which allows water to pass through and dissolve the chalk below. The attention of geologists was first drawn to this series by Prestwich in 1857 (Quart. Journ. Geoi. Soc., vol. xiv, p. 322), and details of all the patches will be found in our President's Memoir on the London Basin (Whitaker, Mem. Geol. Survey, vol. iv, 1872, pp. 339-34 2 ) . As early as 1854 fossils were found in one of these patches at Lenham, in Kent, but their evidence as to the age of the sands was considered doubtful, although Prestwich assigned them to the Crag. In 1886 Mr. Clement Reid made a careful investigation of the deposit at Lenham and its fossils, and satisfactorily proved the deposit to be of Pliocene age (Nature. PROC, GEOL.
Assoc.,
VOL. XVI, PART 10, NOVEMBER, 19oo.J
EXCURSION TO NETLEY HEATH AND NEWLANDS CORNER.
525
vol. xxxiv, p. 34 I). A full account of Mr. Reid's work will be found in his Memoir on the Pliocene Deposits of Great Britain, 1890 (Man. Ceo!. Survey). At page 48 he remarks: "Westward, towards Merstham and Guildford, some of the outliers mapped by the Survey may really be Pliocene as suggested by Prof. Prestwich, but at present there is such an entire absence of positive evidence in favour of this view that it is needless to describe them." This sentence is quoted to show the great interest which attaches to the imperfect fossils found now apparently for the first time at Netley Heath. The patch in which they are found is not mapped as Eocene or Pliocene, but as of doubtful age. The fossils are in the form of casts in af erruginous sandy grit with occasional flint pebbles. The grit much resembles the ferruginous sandstone of the Folkestone Beds, but the presence of the flint pebbles is sufficient distinction. Fragments of fossils referable to the genera Modio!a, and possibly Cyprina, were found by members during the excursion, and fragments of Nassa, Trochus, Cardium, Pedunculus, Tellina, and Thracia have since been found, but in such a poor state of preservation that they cannot be specifically determined. These genera indicate beds of a marine origin, and although they do not enable us to correlate these deposits with those at Lenham with certainty, I am inclined to think that the beds will prove to be of the same age. AlI the above genera except frfodiola have been found at Lenharn, where, on the visit of the Geologists' Association in 1892, 31 species of fossils belonging to 27 genera were obtained. It was remarked by members who had visited Lenham, that the mode of occurence of the fossils and the appearance of the matrix greatly resemble the conditions obtaining at Lenham, The following sections were visited: A sand-pit on the east of a road from Gomshall to East Horsley, showing about 10 feet of yellow and bleached sand, above the sand are some patches of mottled clay and gravel consisting almost wholIy of rolIed fragments of chert and ironstone from the Lower Greensand. Level, about 570 feet. 2. A small pit about 5 feet deep, at a level of rather over 600 feet; the section shows highly ferruginous yellow sand with a few small pebbles and much concretionary iron ore, with chert and patches of rolled flints above. The fossils came from this pit. 3. A sand-pit half-a-mile west of the first pit, showing about I Z feet of yellow sand with a few small pebbles, and in one place a patch of small pebbles above the sand. Level about 600 feet. I.
There is a fourth section on the Heath rather lower than the others, which was not visited. This pit contains a mixture of
LONG EXCURSION TO KESWICK
sand and rolled flints of all sizes, and is exactly similar to one seen on Headley Heath in 1895, at about the same level. The Director remarked that the difference in these three sections on Netley Heath is surprising considering their short -distance apart; but if we suppose that they were formed on a submerged reef away from the coast line-which is Mr. Reid's theory-those portions of the reef near the sea-level would be most affected by the action of the sea, which would prevent shells from accumulating on those portions, and which would have a rounding action upon any loose stones; a state of things which might explain section 1. Leaving Netley Heath, the members followed the track along the top of the North Downs to Newlands Corner, and visited the extensive gravel workings there at about 500 feet O.D. The gravel, which otherwise is similar to that which occurs in most of the sections on Headley Heath, is characterised by the large size of the flints of which it is chiefly composed. Mr. Monckton's explanation of it is that it is probably a very old river gravel, but no doubt newer than the sands and ironstone of Netley Heath. Leaving these sections, the party made their way to Chilworth for tea. After the Director's reply to a most cordial vote of thanks, the geologists returned by the 7.56 train to London. REFERENCES. Geelogical Survey Map, Sheet 8 (Drift Edition). Or dnance Survey i\lap, New Series, Sheet 285, rs. 1862. "V. 'VHITAKEI'.-" On the Western End of the London Basin, etc.," Quart, Journ. Ceo]. Soc., \"01. xviii, p. 273. 188j. H. H. FHEl\'CH.-" Excursion to Con.shall, Netley Heath and Clandon," Proc. Ceol. Assoc .. \"01. x, p. r82.
LONG EXCURSION TO KESWICK. lVloNDAV,
AUGUST
Director:
aoth,
JOHN
to
SATURDAY,
AUGUST
25th,
r90o.
E. MARR, M.A., F.R.S., F.G.S.
Excursion Secretary: FREDERICK i\1EESON.
(RejJort "" THE DIRECTOR.) [PLATES XIII, XIV.]
fifty and sixty members of the Association and their friends assembled at E.. eswick, making the Park Hotel their headquarters. In addition to the official programme, unofficial excursions were conducted on days preceding and succeeding those announced in the official circular, under the leadership of Mr. J. Postlethwaite, F.G S. lIfo71day, Au,!;ust 20tlt.-The day was mainly devoted to an examination of the characters of the Falcon Crag and Bleaberry
BETWEEN
PROC. GEOL. Assoc., VOL. XVI, PART 10, l'\OVEMBER, 1900.J