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Excursion to Chilworth, Blackheath, and Pitch Hill
EXCURSION TO CHILWORTH, BLACKHEATH, AND PITCH HILL. JUNE 18TH, 1904.
Director: R. S. HERRIES, M.A., F.G.S. E xcursion Secretary: H. WALKER, A.R.C.Se., F.G.S. (Rrporf by
THE
DIRECTOR.)
ON the arrival at 11.7 of the 9.24 train from Charing Cross at Chilworth Station, the party proceeded southwards to Blaekheath, passing through a roadside cutting of typical falsebedded Folkestone Sands. From the top of the heath a good view of the surrounding country was obtained, and the Director made a few remarks on the geology and topography of the district. To the north, standing up in front of the chalk downs , was St. Martha's Chapel on a ridge of Folkestone Sands, resting on pebble beds and Bargate Stone exposed in the well-known section near Halfpenny Farm. The valley between was occupied by Atherfield Clay, cut off on the south by a fault nearly parallel to the Peasemarsh anticlinal, where a local disturbance had brought up the Weald Clay . This fault passed almost through Chilworth Stat ion. Turning south and east, the D irector called attention to the spread of barren Folkestone Sands forming the commons of Black, Farley, Albury, and Shere Heaths. From under them to the south the underlying beds of the Lower Greensand rose in a gradual slope, occupied by Winterfold Heath, and farther east by the Hurtwood, till the crest of the escarpment overlooking the Weald was reached. It had often been pointed out on these excursions that th ere was considerable difficulty in making the Lower Greensand beds of Surrey fit the divisions of Folkestone, Sandgate, and Hythe Beds, so easily made on the coast of Kent and adopted by the Geological Survey as the standard for mapping. In this district the Sandgate Beds have disappeared, and though the Folkestone and Hythe Beds occupy the upper and lower positions respectively between the Gault and Atherfield Clay, the exact line of division between the two and the relationship of the not very frequent exposures to one another have been the subject of much dispute. The difficulty in determining the succession is not made easier by the absence of fossils, which (except sponge spicules and fragments of wood ) do not occur except in the Bargate Stone, which on the evidence of its PROC. GEOL. Assoc., VOL. XVIII, PART 10, Igo~.] 34
47°
EXCURSION TO CHI LWORTH,
fossil contents has been placed by the late Mr. Meyer in the Folkestone Series. In 1894 and 1895 Professor J. W. Gregory acted as Director of two excursions to this district, and in his reports, which he illustrated with the map and section now reproduced, he suggested that in this district the names Folkestone, Sandgate, and Hythe should be dropped altogether, and proposed the following lithological divisions: 5. Upper Ferruginous Sands. 4. Pebble Beds and Bargate Stone. 3. Lower Ferruginous Sands and Chert Beds. 2. Passage Learns. I. Atherfield Clay. The object of the present excursion was to see as much as possible of these beds and to examine the evidence for the succession brought forward by Professor Gregory, particularly with regard to the pebble beds. The calcareous Bargate Stone would not be seen because it did not here occur on the south side of the fault previously spoken of; on the other hand there was on this side a great development of cherty beds which were absent on the north side. These were at a lower horizon than the Bargate Stones, as was proved, according to Professor Gregory, by the position of the pebble beds, which are always found associated with the Bargate Stone when the latter occurs, and when it is absent are considerably above the cherty series. The Director hoped to be able to demonstrate the correctness of this view in the course of the walk. Continuing southwards across Blackheath the hill was descended to a little stream that cuts almost, if not quite, down to the Atherfield Clay. About half way down the pebbles were seen, thrown out of a hole dug by the roadside, which had been filled up since the Director was there earlier in the year. Ascending on the other side of the stream the pebbles are again met with at the entrance of the wood known as Sandhurst Copse, just under the" a" of "Lee Farm," on the r-inch Map (New Series). This wood occupies a ridge running east and west, and is really a spur of the Farley Heath area of Folkestone or Upper Ferruginous Sands. The pebble bed appears to mark the base of these sands, as from the point of outcrop the ground rises sharply to the top of the ridge, and on going round the edge of the wood on the southern slope of the ridge the pebbles were again seen in the upper part of the fields above Shamley Green and Woodhill. Lower down the slopes pieces of chert may be picked up on the fields, but this was not verified owing to the growing crops. Farther down at Woodhill, where are some ponds, the Atherfield Clay fills the bottom of the valley. A halt was made for luncheon in the wood, and the next section examined was the sand pit by the side of the road a
BLACKHEATH, AND PITCH HILL.
47 1
little north of Upper Woodhill (near the figure 453 in Prof. Gregory's map). This shows false-bedded yellow sands of the usual Folkestone character, but there are thin beds of small quartz pebbles, lydian stones, etc., near the bottom of the section which run up into the sands in irregular lines and patches. This section, therefore, seems to represent the Upper Ferruginous Sands and the top of the pebble beds. Farley Heath was then crossed to a point a little south of Mayor House Farm, where at the edge of a small copse (indicated on Prof. Gregory's map as an outlier of Upper Sands) there is a very good exposure of the pebble beds, forming quite a fine gravel on the surface of the ground. The Director mentioned that these pebbles spread over the fields north of Mayor House Farm, the slope of the ground towards Farley Green being practically identical with the dip-slope. The succession of the beds is made very apparent at the point where the party were standing. At the foot of the hill about a hundred feet below was Pit House Farm, where the chert beds are developed, which spread away to the south over the high ground forming Winterfold Heath. It is clear, therefore, that if the pebble beds represent the horizon of the Bargate Stone, and their position immediately below the little outlier of Upper Sands mentioned above warrants us in concluding that they do, then the Bargate Stone must be considerably higher in the series than the chert beds. The pebbles themselves are very small, from half to three-quarters of an inch in length, and are mostly quartz, with an admixture of lydian stone, etc. The hill was then descended, and the occurrence of chert noted on the lower part of the slopes and in the lane leading up from Pit House Farm to Winterfold Heath. The latter is a wild barren plateau sloping up to the edge of the Lower Greensand escarpment, whence a fine view of the Weald country was obtained. The party walked eastwards across the heath to Ewhurst Windmill, seeing the quarries of sandstone and chert on the road west of the mill, and then came down to the larger quarries at Pitch Hill visited on an excursion to the same district last year. These were examined, as well as the underlying sands in the large sand pit lower down. These sands differ from the Upper or Folkestone Sands in not being false-bedded. The Director supposed that they represented Prof. Gregory's Passage Loams, but he doubted whether it was necessary to make them into a separate division, though they seemed to occur all along this line of hills below the cherts and sandstones. Miss Spottiswoode had kindly sent her carriage to this point, and gave the ladies a lift back to her house at Drydown, near Shere, whither the rest of the party followed on foot by the road through the Hurtwood. Here the memhers were very kindly entertained to a substantial tea, and after Mr. Whitaker had expressed the cordial thanks of
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FIG, 33 -MAP OF THE NEIGHBOURHOOD OF WOODHIlL, NEAR CHILWORTH,-.7, W, Grtgory.
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FIG . H .- S ECT ION FROM S T. MA RT H A'S ACROSS B LACKH EAT H TO S T ROU D F AR M. -J .
Vert ical S cale, r inc1l=/oo f eet.
W . Gregory .
H orizontal Scale , / in ch=2 miles.
Shading as below. T he black band to the left is Barga te stone; and a
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includes the Weald Clay.
474
EXCURSION TO HOLBOROUGH AND BURHAM.
the party to Miss Spottiswoode for a second time making the Association welcome, they proceeded across the fields to Gomshall Station, and returned to London by the 6.59 train. REFERENCES. Geological Survey Map, Sheet 8. Ordnance Survey Map (new series), Sheet 285. 1866. MEYER, C. J. A._" Notes on the Correlation of Cretaceous Rocks." Geol. Mag., vol. iii, p. 13. 1868. MEYER, C. J. A.-liThe Lower Greensand of Godalming." Geologists' Association. 1875. TOPLEY, W._" Geology of the Weald." Mem. Geol. SU1·vey. 1894. LEIGHTO!'l, T.-" The Lower Greensand above the Atherfield Clay of East Surrey." Quart. :!ourn. Geol. Soc., vol. Ii, p. 101. 1894. GREGORY, J. W.-" Excursion to Guildford and Shalford." Proc, Geo!. Assoc., vol. xiii, p. 377. J895. GREGORY, J. W.-" Excursion to Chilworth.' Proc, Geot. Assoc.,. vol. xiv, p. 120. 1903. HERRIES, R. S.-" Excursion to Felday, Holmbury Hill, and the Hurtwood." Proc. Geo!. Assoc., vol. xviii, p. 297.
EXCURSION TO HOLBOROUGH AND BURHAM. JULY 2ND, 1904.
Director and Excursion Secretary: G. E. DIBLEY, F.G.S. (Report by THE DIRECTOR.)
UPON arriving at Halling Station the party proceeded to Upper Halling, and crossing the Pilgrim Road descended to the large pits belonging to Messrs. Lee & Co. The upper workings are in the Rhynchone/la cuuieri-zcme, and the two larger pits in the Holaster subglobosus. Not many fossils were seen on this occasion. After leaving these extensive pits the members were hospitably entertained at The Cedars, Holborough, by Mrs. Raven. The valuable collection of antiquities derived chiefly from the neighbourhood by Mr. Raven was much appreciated, as also the collection of chalk fossils from Messrs. Lee's pits, which serve to well illustrate the fauna of the various zones. Halling churchyard was visited en route to the ferry, and Mr. F. J. Bennett, F.G.S., drew attention to the quaint ornamentation of certain headstones, and compared them with drawings made from others in the vicinity. Messrs. Peters' pits were next visited. These workings cover a large area, and consist of one large quarry in the Holaster subglobosus-zone, another includes the upper part of this zone and the Aainocamax marls, while the third is in the
Director: R. S. HERRIES, M.A., F.G.S. E xcursion Secretary: H. WALKER, A.R.C.Se., F.G.S. (Rrporf by
THE
DIRECTOR.)
ON the arrival at 11.7 of the 9.24 train from Charing Cross at Chilworth Station, the party proceeded southwards to Blaekheath, passing through a roadside cutting of typical falsebedded Folkestone Sands. From the top of the heath a good view of the surrounding country was obtained, and the Director made a few remarks on the geology and topography of the district. To the north, standing up in front of the chalk downs , was St. Martha's Chapel on a ridge of Folkestone Sands, resting on pebble beds and Bargate Stone exposed in the well-known section near Halfpenny Farm. The valley between was occupied by Atherfield Clay, cut off on the south by a fault nearly parallel to the Peasemarsh anticlinal, where a local disturbance had brought up the Weald Clay . This fault passed almost through Chilworth Stat ion. Turning south and east, the D irector called attention to the spread of barren Folkestone Sands forming the commons of Black, Farley, Albury, and Shere Heaths. From under them to the south the underlying beds of the Lower Greensand rose in a gradual slope, occupied by Winterfold Heath, and farther east by the Hurtwood, till the crest of the escarpment overlooking the Weald was reached. It had often been pointed out on these excursions that th ere was considerable difficulty in making the Lower Greensand beds of Surrey fit the divisions of Folkestone, Sandgate, and Hythe Beds, so easily made on the coast of Kent and adopted by the Geological Survey as the standard for mapping. In this district the Sandgate Beds have disappeared, and though the Folkestone and Hythe Beds occupy the upper and lower positions respectively between the Gault and Atherfield Clay, the exact line of division between the two and the relationship of the not very frequent exposures to one another have been the subject of much dispute. The difficulty in determining the succession is not made easier by the absence of fossils, which (except sponge spicules and fragments of wood ) do not occur except in the Bargate Stone, which on the evidence of its PROC. GEOL. Assoc., VOL. XVIII, PART 10, Igo~.] 34
47°
EXCURSION TO CHI LWORTH,
fossil contents has been placed by the late Mr. Meyer in the Folkestone Series. In 1894 and 1895 Professor J. W. Gregory acted as Director of two excursions to this district, and in his reports, which he illustrated with the map and section now reproduced, he suggested that in this district the names Folkestone, Sandgate, and Hythe should be dropped altogether, and proposed the following lithological divisions: 5. Upper Ferruginous Sands. 4. Pebble Beds and Bargate Stone. 3. Lower Ferruginous Sands and Chert Beds. 2. Passage Learns. I. Atherfield Clay. The object of the present excursion was to see as much as possible of these beds and to examine the evidence for the succession brought forward by Professor Gregory, particularly with regard to the pebble beds. The calcareous Bargate Stone would not be seen because it did not here occur on the south side of the fault previously spoken of; on the other hand there was on this side a great development of cherty beds which were absent on the north side. These were at a lower horizon than the Bargate Stones, as was proved, according to Professor Gregory, by the position of the pebble beds, which are always found associated with the Bargate Stone when the latter occurs, and when it is absent are considerably above the cherty series. The Director hoped to be able to demonstrate the correctness of this view in the course of the walk. Continuing southwards across Blackheath the hill was descended to a little stream that cuts almost, if not quite, down to the Atherfield Clay. About half way down the pebbles were seen, thrown out of a hole dug by the roadside, which had been filled up since the Director was there earlier in the year. Ascending on the other side of the stream the pebbles are again met with at the entrance of the wood known as Sandhurst Copse, just under the" a" of "Lee Farm," on the r-inch Map (New Series). This wood occupies a ridge running east and west, and is really a spur of the Farley Heath area of Folkestone or Upper Ferruginous Sands. The pebble bed appears to mark the base of these sands, as from the point of outcrop the ground rises sharply to the top of the ridge, and on going round the edge of the wood on the southern slope of the ridge the pebbles were again seen in the upper part of the fields above Shamley Green and Woodhill. Lower down the slopes pieces of chert may be picked up on the fields, but this was not verified owing to the growing crops. Farther down at Woodhill, where are some ponds, the Atherfield Clay fills the bottom of the valley. A halt was made for luncheon in the wood, and the next section examined was the sand pit by the side of the road a
BLACKHEATH, AND PITCH HILL.
47 1
little north of Upper Woodhill (near the figure 453 in Prof. Gregory's map). This shows false-bedded yellow sands of the usual Folkestone character, but there are thin beds of small quartz pebbles, lydian stones, etc., near the bottom of the section which run up into the sands in irregular lines and patches. This section, therefore, seems to represent the Upper Ferruginous Sands and the top of the pebble beds. Farley Heath was then crossed to a point a little south of Mayor House Farm, where at the edge of a small copse (indicated on Prof. Gregory's map as an outlier of Upper Sands) there is a very good exposure of the pebble beds, forming quite a fine gravel on the surface of the ground. The Director mentioned that these pebbles spread over the fields north of Mayor House Farm, the slope of the ground towards Farley Green being practically identical with the dip-slope. The succession of the beds is made very apparent at the point where the party were standing. At the foot of the hill about a hundred feet below was Pit House Farm, where the chert beds are developed, which spread away to the south over the high ground forming Winterfold Heath. It is clear, therefore, that if the pebble beds represent the horizon of the Bargate Stone, and their position immediately below the little outlier of Upper Sands mentioned above warrants us in concluding that they do, then the Bargate Stone must be considerably higher in the series than the chert beds. The pebbles themselves are very small, from half to three-quarters of an inch in length, and are mostly quartz, with an admixture of lydian stone, etc. The hill was then descended, and the occurrence of chert noted on the lower part of the slopes and in the lane leading up from Pit House Farm to Winterfold Heath. The latter is a wild barren plateau sloping up to the edge of the Lower Greensand escarpment, whence a fine view of the Weald country was obtained. The party walked eastwards across the heath to Ewhurst Windmill, seeing the quarries of sandstone and chert on the road west of the mill, and then came down to the larger quarries at Pitch Hill visited on an excursion to the same district last year. These were examined, as well as the underlying sands in the large sand pit lower down. These sands differ from the Upper or Folkestone Sands in not being false-bedded. The Director supposed that they represented Prof. Gregory's Passage Loams, but he doubted whether it was necessary to make them into a separate division, though they seemed to occur all along this line of hills below the cherts and sandstones. Miss Spottiswoode had kindly sent her carriage to this point, and gave the ladies a lift back to her house at Drydown, near Shere, whither the rest of the party followed on foot by the road through the Hurtwood. Here the memhers were very kindly entertained to a substantial tea, and after Mr. Whitaker had expressed the cordial thanks of
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FIG, 33 -MAP OF THE NEIGHBOURHOOD OF WOODHIlL, NEAR CHILWORTH,-.7, W, Grtgory.
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FIG . H .- S ECT ION FROM S T. MA RT H A'S ACROSS B LACKH EAT H TO S T ROU D F AR M. -J .
Vert ical S cale, r inc1l=/oo f eet.
W . Gregory .
H orizontal Scale , / in ch=2 miles.
Shading as below. T he black band to the left is Barga te stone; and a
f
includes the Weald Clay.
474
EXCURSION TO HOLBOROUGH AND BURHAM.
the party to Miss Spottiswoode for a second time making the Association welcome, they proceeded across the fields to Gomshall Station, and returned to London by the 6.59 train. REFERENCES. Geological Survey Map, Sheet 8. Ordnance Survey Map (new series), Sheet 285. 1866. MEYER, C. J. A._" Notes on the Correlation of Cretaceous Rocks." Geol. Mag., vol. iii, p. 13. 1868. MEYER, C. J. A.-liThe Lower Greensand of Godalming." Geologists' Association. 1875. TOPLEY, W._" Geology of the Weald." Mem. Geol. SU1·vey. 1894. LEIGHTO!'l, T.-" The Lower Greensand above the Atherfield Clay of East Surrey." Quart. :!ourn. Geol. Soc., vol. Ii, p. 101. 1894. GREGORY, J. W.-" Excursion to Guildford and Shalford." Proc, Geo!. Assoc., vol. xiii, p. 377. J895. GREGORY, J. W.-" Excursion to Chilworth.' Proc, Geot. Assoc.,. vol. xiv, p. 120. 1903. HERRIES, R. S.-" Excursion to Felday, Holmbury Hill, and the Hurtwood." Proc. Geo!. Assoc., vol. xviii, p. 297.
EXCURSION TO HOLBOROUGH AND BURHAM. JULY 2ND, 1904.
Director and Excursion Secretary: G. E. DIBLEY, F.G.S. (Report by THE DIRECTOR.)
UPON arriving at Halling Station the party proceeded to Upper Halling, and crossing the Pilgrim Road descended to the large pits belonging to Messrs. Lee & Co. The upper workings are in the Rhynchone/la cuuieri-zcme, and the two larger pits in the Holaster subglobosus. Not many fossils were seen on this occasion. After leaving these extensive pits the members were hospitably entertained at The Cedars, Holborough, by Mrs. Raven. The valuable collection of antiquities derived chiefly from the neighbourhood by Mr. Raven was much appreciated, as also the collection of chalk fossils from Messrs. Lee's pits, which serve to well illustrate the fauna of the various zones. Halling churchyard was visited en route to the ferry, and Mr. F. J. Bennett, F.G.S., drew attention to the quaint ornamentation of certain headstones, and compared them with drawings made from others in the vicinity. Messrs. Peters' pits were next visited. These workings cover a large area, and consist of one large quarry in the Holaster subglobosus-zone, another includes the upper part of this zone and the Aainocamax marls, while the third is in the