We sometimes imagine the editor of some new caving club
journal putting a sheet of paper into his typewriter and, while he waits for
inspirations to arrive, typing Volume I, Number 1 at the head of the paper.
Statistically speaking, the chances of his reaching g Volume
II are not very good. It is therefore
with some degree of pride that we present this two hundredth issue of the
B.B. The B.B. has had its fair share of
ups and downs in the past and, on two occasions at least, it would have not
been surprising if its publication had ceased but somehow, in the general
manner of the B.E.C., it seems to have survived in spite of circumstances.
The B.B. has been called a lot of things in its time, not
all of them complimentary. This, to some
extent, may be due to its rather odd position amongst the Journals of
Mendip. It is not a completely serious
Caving Journal although from time to time it does publish articles which can
stand comparison with anything that is produced elsewhere an example of which
appears in this issue. It is not, on the
other hand, simply a newsletter. The
present editor likes to think of it as a club magazine which, like the club it
serves, does good work from time to time but does not take itself too
seriously.
As far as the future is concerned however, 1965 will see
some new innovations in the field of caving journals with the advent of
nationally distributed properly printed glossy magazines like the
Speleologist. Whilst welcoming this and
other magazines of its type we feel that it would be a bad thing if the club
journals were to decline into newsletters as a result. To a great extent, this will depend on the
relative amount of serious authorship which the club journals can still attract
in the face of temptation to authors of better presentation and more widespread
distribution which the national journals will be able to offer. It thus becomes of some importance to the
club to improve the layout and all round appearance of the B.B. and steps are
being taken to effect this type of improvement.
It is hoped that, starting in the New Year, the B.B. will be
produced by offset litho process which should result in a neater looking
appearance, enabling drawings to be included with fine detail and headings etc.
to be more evenly printed. At a later
stage in the year, it is hoped to be able to get the B.B. actually typeset and,
in conjunction withy the use of a better grade of paper, this should result in
a professional appearance
As mentioned in the recent A.G.M., all this will cost the
club rather more than the present magazine, which is produced on a shoestring
budget, and it will be largely wasted unless articles of all types, but of a
high standard, are forthcoming. During
the last few months, there has been a good steady flow of material for
inclusion in the B.B. Let us see
whether, in 1965, we can improve both the appearance and the standard, and
eventually the size, so that the chances of the B.B. reaching its Four
Hundredth Edition are not impaired by us.
Alfie
*****************************************
Dont forget you may purchase B.E.C. CAVING REPORTS from
Bryan Ellis. He also has a number of
surveys and other caving literature. Why
not get in touch with him and treat yourself to some interesting reading
matter???
Contents
A.G.M. & Dinner
The 1964 Annual General Meeting of the B.E.C. opened at
2.45pm, there being over 50 members present. Dan Hassell was elected as Chairman unanimously. The Chairman then called for the ballot
papers and any members resolutions. Mo
Marriott. Spike Rees and Nigel Hallet were elected as tellers for the ballot. The tellers retired to count the votes
(presumably so that they could take their socks off and count up to
twenty). Meanwhile, the Chairman read
the minutes of the 1963 A.G.M., which were accepted by the meeting.
The Hon. Secretary then gave his report. There had been 31 new acceptances for
membership during the year. Thus intake
of about 30 new members per annum was typical of the last few years, but as
fewer members were leaving the club, the total membership was rising and now
stood at 172. The Dinner was being held
in
year. Members were sorry to hear of the
deaths of two members during the year Lionel Williams and Ian Dear. Ian had left £150 and all his caving and
climbing equipment to the club and had in addition left a further sum of £300
to assist junior members who wished to cave abroad. The remaining point the Secretary wished to
bring to the attention of members was that during the year, a National Caving
Organisation has been suggested, but this suggestion is not acceptable to
Mendip clubs, who are forming a body with the object of maintaining the status
quo. The adoption of the Secretarys
report was proposed by R.A. Setterington and seconded by Gordon Tilly.
The Hon. Treasurer then gave his report. For some reason, the traditional pretence of
surprise at finding this was the same bloke was absent this year. He apologised for the incomplete nature of
his financial statement but explained that £29 had been received from the Hut
Warden too late for inclusion. Receipts from
Redcliffe and from membership fees have increase this year. He reminded members that he had said last
year that the expenditure of £5 on tackle was, in his opinion, too low. However, £60 spent this year was probably too
high to be continued at this rate (cries of Stop-Go economy!). The Belfry Expenditure includes the cost of
the water heater and the new mattresses but not the £29 receipts. We now have paid our share of the C.C.C.
legal expenses and the deficit on club ties means that a large stock now exists
for people not wearing them. To sum up,
the clubs financial position is adequate and should be further improved when
the legacy is received.
Oliver Lloyd asked how would the legacy be invested? The Hon. Secretary replied that it would be
invested in Savings Bonds. Mike Luckwill
asked how it was intended to be used. The Chairman said this subject would be coming
up later. Gordon Tilly then proposed
that the report be adopted and this was seconded by John Ransom and carried.
The Caving Secretary being still occupied with the counting
of votes, the Climbing Secretary gave his report next. Trips have been run as announced during the
year in the B.B. and elsewhere. These
have been mainly to North Wales, but
and
amount of local climbing has also been carried out. There have been quite a few requests for
information but now many new recruits have been forthcoming. There was no questions, and the adoption of
the report was proposed b y Gordon Tilly (who could not in any case equal Mike
Luckwills record for proposing reports at the A.G.M. since he will not be able
to propose the acceptance of his own Hut Wardens report later in the
proceedings!) and seconded by Kangy King.
The Tackle Officers report followed. He stated that this year, no tackle had been
lost. We are now the proud possessors of
410 feet of ladder and 780 feet of lifeline. We have 16 tethers, ranging from 18 inches to 27 feet and we should
finish up, when the present ladder building programme is completed, with 630
feet of ladder. Dave Irwin asked whether
the expenditure quoted by the Hon. Treas. Covered all the remaining ladder. The
Tackle Officer said that it did all except the wire. A vote of thanks was recorded to the Tackle
Officer for his work in producing so much tackle. The adoption of the report was proposed by
Mike Luckwill and seconded by Gordon Tilly and carried.
The Editor of the B.B. then gave his report. Since most of what he said is in the forward
to the issue of this B.B., it will be omitted here. John ransom proposed the report be
adopted. This was seconded by Gordon
Tilly and carried.
The Hut warden announced that bed nights were again very
high and stood at approximately 1800. Very
few breakages had occurred at the Belfry. The hot water system has gone a long way towards dealing with the
washing up situation, but has proved expensive to run. He suggested that it was enough for the time
being. The Hut Warden concluded his
report by saying that he would like to express his thanks to club members for
their co-operation and particularly to Sett and Jan. Kangy asked why the hot water system was held
to be expensive. He wondered if Gordon
could enlarge on this point. Gordon
replied not particularly. Some
discussion on the cost followed. Alan
asked if this years committee could do an analysis of the cost. The Chairman suggested that this be left to
the Committee to decide whether they considered this to be necessary. Alan Thomas asked if the heat from the Belfry
Stove could be utilised in some way. Alfie thought that this was not really practicable. Frank Darbon then proposed that the report be
adopted. This was seconded by Alan
Thomas and carried.
The Hon. Sec. then read a note from Bryan Ellis who stated
that no Caving Reports had been published during the year, but that the sales
of the previously published reports continue. A balance amounting to £4.17.8 is in hand towards the cost of publishing
a further manuscript. Alan Thomas asked
whether anyone knew if a further manuscript was in the course of
preparation. Alfie replied that he
thought one was being prepared by Dave Irwin on the Long Chamber area of St.
Cuthberts. This was confirmed by the
author. The Chairman suggested that continued publicity be given to the sale of
caving Reports in the B.B. This was
noted by the editor.
The Hon. Librarians Report followed. Borrowing was sporadic amongst the older
members but continues amongst the younger members. There had been some 114 borrowings during the
year. Ian left the library all his books
and surveys and maps of caving areas. As
a result we have new maps of all the caving areas in
bound. There were no questions and Alfie
proposed that the report be adopted. This was seconded by Frank Darbon and carried.
The Belfry Engineer then gave his report. A coal and coke bin had been made in the
Belfry and two large lockers which were big enough to take rucksacks. The leaks have been repaired in the
roof. A urinal had been built out at the
back. The Belfry had been creosoted, the
ceiling had been done, the asbestos panel for the chimney is being fitted and
the car park extended. There were no
questions and Gordon Tilly therefore moved that the report be adopted. This was seconded by Sett and carried.
At this stage the result of the ballot became known and was
read out by the Chairman. Voting was as
follows: –
Total number of members voting
87. Votes cast for Bob Bagshaw (79); Norman Petty
(78); Roy Bennett (75); Alfie (74); Alan Thomas (65); Kevin Abbey (64); Dave
Irwin (63); Gordon Tilly (53); Keith Franklin (47); Mike Palmer (44); Sett
(43); John Ransom (38); Phil Kingston (20). The Committee therefore consists of Bob Bagshaw, Norman Petty, Roy
Bennett, Alfie, Alan Thomas, Kevin Abbey, Dave Irwin, Gordon Tilly, and Keith
Franklin
After an adjournment for light (non-alcoholic) refreshments,
the Caving Secretary gave his report. He
said that the general level of caving had shown an increase, with Cuthberts
overshadowing all other caves in popularity. There had been no major discoveries outside Cuthberts. However, activity was increasing in digging
projects. Castle Farm Swallet was being
energetically pursued, also Hunters Hole. B.E.C. members has also been active in work on the S.E. Inlet Series in
Swildons. The level of co-operation
amongst cavers was good, but there was some room for improvement. A practice Rescue had been held in
Cuthberts. The New Entrance was now in
full commission and the Old Entrance had been filled in. He concluded with a plea for some serious
scientific studies in Cuthberts. Questioning the Caving Secretary, Roger Stenner asked why the work on
new caves in
included? The Caving Secretary said that
he thought this work had occurred last year, and asked whether more recent work
had been written up in the log. Gordon
Tilly proposed that the report be adopted and this was seconded by Alan and carried. A vote of thanks to the Caving Secretary was
proposed by Kangy King and carried.
Under Members Resolutions, Alfie proposed that No person
under sixteen may stay at the Belfry without the previous consent of the Hut
Warden and the presence of Parent or Guardian. This was seconded by Gaff and carried (38 for, 3 Against)
A resolution that every effort again be made to install the
new shower system within the next six months was proposed by Jill Tuck and
seconded by Alfie. Alan Thomas reported
that work was in hand but was being delayed at present due to a general
shortage of copper pipe. The motion was
carried nem. com.
A further resolution by Jill Tuck that more blankets be
acquired for the Belfry was seconded by Roger Stenner and defeated (1 for, 38
against).
Another resolution by Jill Tuck that a new telephone line
be laid out on Cuthberts was discussed and an amendment was proposed by Mo
in view of the technical possibilities that a communications system be
installed in St. Cuthberts The
amendment was seconded by Alfie and the amended resolution was carried
unanimously.
The meeting went on to discuss the terms of Ians bequest.
Since this will be the subject of a separate announcement, it is omitted from
these notes. There being no further
business the Chairman declared the meeting closed.
The Annual General Meeting was followed by the Annual Dinner
which was held for a change this year in Fairfax House, and the Co-op
Headquarters, in
B.E.C. uncanny knack of anticipating the next government is not clear but, at
any rate, those who feared that they might have to drink Wheatsheaf beer were
soon put at their ease. It is reported
that the actual meal (which the writer personally regards merely as serving the
function of blotting paper at these functions) was not adequate for some of our
growing lads! The general feeling seems
to have been that it was not bad, but should have been better for the extra
money.
The speeches went off well, Alan Thomas new gimmick this
year being the use of a tape recorder to enable absent friends to reply in
person. Unfortunately the volume was not
as high as the size of the gathering warranted. The speeches (including the presentation of a useful present to Kevin
Abbey) were followed by one of Kangys floor shows. This time it took the form of a pageant of
Caving through the Ages. This
commenced with a wonderful spectacle of Barry Wilton as Homo Speleogenesis
and Early Homo, who demonstrated the origin of painting by numbers. Next we saw Frank as a Celtic Caver (complete
with A.O.I.F.L. which he waved triumphantly). This was followed by an Elizabethan Caver portrayed by Keith Franklin
and showed us Sir Fancy Cake nonchalantly playing shove hapenny while the Wessex
were invading Cuthberts. Having won his
game, he then pulled the plug out of the dam and drowned them. This was followed by a Victorian Caver in the
person of Gaff Fowler engaged in robbing caves of stal. and oppressing the
working classes (played by Roy Bennett). Finally, we had a glimpse into the future and saw a Super Caver in a
topless wet suit. Keith Franklin played
this part as well as the City Gent Type Caver who followed. I have, of course, missed out the touching
scene which came between the Victorian Caver in which Balch meets Martel in
Celtic embrace.
More drinking followed this pageant when another series of
interludes occurred. Oliver Lloyd was
persuaded to sing his trilogy of Swildons songs; a man recited a poem and a
slightly shambolic singing act took place. A static exhibition featured various aspects of club activities. Displays of caving and climbing photographs;
recent progress in St. Cuthberts; Castle Farm Dig; the B.B.; Caving Gear and a
collection of finds in cave quarries were arranged round the walls of the
room. The dinner appeared to have been a
success at least, not many grumbles have been heard to date!
Note: This account of the A.G.M. and Dinner is not
an official one or guaranteed free from mistakes.
*****************************************
R.J.
Bagshaw. Hon. Secretary and Treasurer.
N. Petty. Tackle Officer
Roy Bennett. Climbing
Secretary & B.B. Postal Department.
Alfie. Committee
Chairman and Hon. Editor, B.B.
Alan Thomas. Belfry Engineer. Kevin
Abbey. Assistant Caving Secretary.
Dave Irwin. Caving Secretary and Minutes Secretary.
Gordon Tilly. Hut Warden.
Keith Franklin. Assistant Caving Secretary.
Joan Bennett. Hon, Librarian.
State of the parties. Caving Secretaries Party 3, Independents 6.
The Sequence of Development of St. Cuthberts Swallet Part 1
by Derek Ford.
This account is written for fellow members of the Bristol
Exploration club in the hope that it may help them to enjoy their favourite
cave even more. It is based on a study
made there during the summers of 1960 and 1961. This was aimed at determining the mode and sequence of development down
below, which was then compared to similar studies made of Swildons Hole;
the Goughs group of caves at Cheddar, and Wookey Hole.
In many respects St. Cuthberts proved to be the most
complex and interesting of these caves. This is partly because it is the oldest (the sequence for events at
G.B., for example, is much shorter) and partly because, in the past, it drew
its water from an unusually large surface basin with a varied assemblage of
rocks. Today the cave drains something
less than half a square mile of the adjacent parts of Stock Hill and North
hill, but in former times, its took water from well north of the Miners Arms
via Stock Hill North Hill Valley.
This narrative gives a sequential description of the
creation of modern scenery in the cave. It omits almost all the evidence, for the sake of brevity. When typed out with the evidence my account
of the cave ran to over 200 pages, supported by some 30 diagrams. St. Cuthberts is really quite a place.
Its history is divided into phases and sub-phases,
distinguished by greater or lesser changes in the prevailing dynamic
conditions. These phases are can be
grouped into three major stages of development: Phreatic Erosion, Vadose Infill
and Vadose Re-excavation.
MORPHOLOGICAL SUB-DIVISIONS OF THE CAVE
For the purpose of this description, the cave may be divided
into four areas having distinctly different forms.
First is a
central complex of partially collapsed chambers, extending to form Long Chamber
and Coral Chamber in the west, to the September Chambers in the east. These chambers rest on, or close to, the base
of the limestone which are here lying on shaly transitional strata sloping at
about 38 degrees to the S.S.E. The
chambers follow the bedding planes and several systems of joint and fault
fractures, which coalesce in this area creating a very tangled structure.
Second is the
Gour Rift. This is the biggest passage
in the cave, following a major vertical, fault. The original Gour Rift of the explorers is only the South Eastern end of
it. To the
West
are further accessible parts separated from each other by places where stream
laid fill and stalagmite reaches the roof.
Third is the
central complex and Gour Rift Everest Passage; the Fingers; The Rabbit
Warren; The Railway Tunnel; Main Stream Passage; The Warren Extension and The Tin
Mine. All are comparatively small and
were developed to convey water from the big chambers to the north, to the rift
passage.
Fourth are a
series of comparatively recent inlet passages which developed to feed the
Central Complex or underneath it long after it had been expanded by water from
other sources. The inlets are the
Series and High Chamber.
SEQUENCE OF DEVELOPMENT
The Phreatic
Expansion. About two thirds of the
volume of the known cave can be attributed to solution under phreatic
conditions (complete water fill beneath a water table surface) or to collapse
which followed immediately after that fill was drained. There are two distinct phases of phreatic
expansion
(a) Phreatic Bore
Passage Phase. In this phase, water
entered the known cave through Rocky Boulder Series and the collapsed area at
the N.W. corner of Upper Traverse Chamber. The contemporary water table was at, or above 660 feet O.D. A series of long narrow rift chambers was
opened below it, between Coral Chamber and Upper Traverse Chamber. They were drained into Gour Rift by a
remarkable system; the
bore passages. By this trem, I mean a
very efficient conduit, with minimum wall friction and little or no wastage of
the solvent power of the water eroding large blind alleys. The
bores were very efficient, being nearly circular in cross-section (a circular
pipe has least friction) and following fairly direct linear courses. There were four principle bores, all
converging to flow to the E.S.E. and arranged in a tier the highest to the
north. The highest drained the southern
end of Upper Traverse Chamber and may be followed east from the junction of
that chamber and Harem Passage, to a stalagmite choke. The second was the Railway Tunnel draining an
early rift in the area of the Cascade and the southeast part of Boulder
Chamber. It spilled some water south
(down dip) through lesser bore passages. Due to this loss of water, the dimensions of the Tunnel are
progressively reduced. The third bore
was much the smallest. It ran from
Everest Passage, through the Fingers and the centre of the
Plantation Junction. It received many
tributaries from Tunnel Passage and distributed water to the fourth bore. The latter is the oldest part of the Main
Stream Passage. It began at the head of
Everest Passage, drawing water from the precursors of Everest Boulder and
Curtain Chambers, spilled a little into the Rat Run and then meandered E.S.E.
to turn into its discharge the Great Rift at the Dining room. Here the roof of the rift (Cerberus Hall) is
exceptionally high, being driven upwards by the erosive power of waters
delivered into its base with some force. These waters then moved S.E. towards the present termination of the
cave.
The three higher bores all fed into Plantation
Junction. East of their terminal chokes,
the Upper Traverse and Tunnel bores (the two largest) split into a series if
distributaries, which can be seen, almost entirely choked with stalagmite,
crossing the extension passage at its floor level. Beyond it, they turned south, developing the
choked passage which the Plantation Stream follows today and reaching the junction
at some place beneath the great sand and stalagmite bank there. From the junction, the water cut a fine
elliptical bore passage straight to Beehive Chamber, where it turned steeply
upwards (Pyrolusite Series) to enter the Gour Rift more or less directly above
the highest gours. The modern route from
Beehive Chamber to the rift is a subsequent bore passage, also climbing up to
its outlet. As at Cerberus Hall, the
roof of Gour Rift is highest over these points of input.
The dimensions of individual bore passages remain nearly
constant between tributaries or distributaries. Thus, making some assumptions, it is possible to calculate the
velocities of the formative flow through them. Velocities are very low, despite the efficient flow cross sections of
the passages. The picture is one of water
moving slowly through a mesh of pipes from one system of semi-static reservoirs
(the central complex) to another (the Gour Rift). Correspondingly, the water table was
exceptionally flat and stable and the time taken to expand the cave thus far
was possible as long as all its later phases combined.
(b) Phreatic
Disintegration Phase. A change in
the dynamics of flow, or chemistry, of the groundwater then tore much of the
efficient mesh of bore passage apart and greatly increased the volume of the
cave. The water table remained at 600
feet. Most of the bore passages
developed into bedding planes, the line of the plane bisecting the tube. Disintegration took the form of a wide
expansion along the plane, on one or both sides of the tube. Often the lower half of the tube was
destroyed altogether. This can best be
seen along the direct traverse from The Fingers to the Sewer. Most of the Sewer Passage is a result of this
phase. So is the manner in which the
south wall of the extant Railway Tunnel is torn out along the guiding
plane. To the west, the roof of the
tunnel can be traced curving up a great joint surface over the foot of the
Cascade. The floor here was entirely dissolved
away.
There was much expansion in size of the Central
Complex. The most important development
was a direct connection between the complex and the rift, short circuiting the
old flow lines, through Long Chamber and Curtain Chamber, joining the Rift at
roof level at the choked point between
and Mud Ball Chambers. Theses two
chambers are largely a product of the phase.
A new phreatic stream from an independent sink entered the
system during this phase. It opened up
September Series and thus impinged on the Eastern end of the bore passage
mesh. This was overloaded as a result
and the extension passages below Cross Legs Squeeze were developed as
remarkable sub-water table overflow channels. In many parts it will be found that their course is not controlled by
any notable fractures at all.
(c) The fall of the Water Table. At the end of the second phase, the water
table fell from above 660 feet to a little below its present level of 380 feet
O.D. The rate of fall was slow at first
but there were no prolonged stands above 380 feet. The vertical amplitude of the drop at least
200 feet is greater than any detected in the other central Mendip caves that
I have studied and requires explanation.
Fall of the water table in a Mendip inlet cave, such as St.
Cuthberts is caused by a fall of roughly equal proportions at the outlet. In simplest terms, falls at the outlet caves
such as Wookey and Cheddar, can be attributed to falls in the level of a past
sea filling the Somerset Moors to the south. There have been several such falls from maximum level above 500 feet
O.D. The vertical amplitude of each fall
was around 100 feet or less. Swildons
Hole is a complicated cave to explore because it has developed new systems of
passages in response to each of the four major falls of the water table
transmitted to it by the outlet.
St. Cuthberts shows only one fall, its amplitude as big as
the aggregate of the four in Swildons Hole. This is because its outlet lies amidst an unusual geological complexity,
called the Ebbor Thrust Zone. (F.R.A.
Welch, 1929. Quarterly Journal of the
Geological Society of
Page 45). During the phreatic phases,
St. Cuthberts discharged its water through caves in Ebbor Gorge. Cave remnants can be seen at the steepest
point there (Bridged Pot Shelter, &c). The level of the discharge was above 500 feet. It was held at this height by a block of
impermeable rocks, quartistic sandstones of millstone grit (lower coal measure
age) infaulted across the mouth of the gorge. These functioned as a subterranean dam and held the water up at Ebbor
Gorge during the several falls of sea level on the downstream side. Finally, when the sea level stood at
somewhere around 240 feet O.D., the pressure effected by the groundwater held
above 500 feet caused a leak to develop around the side of the dam. Wookey Hole is the downstream end of this
underground leak. The breakout at Wookey
drained St. Cuthberts via the present terminal stream passage. During the phreatic phases the water probably
left Gour Rift via its impassable narrow southern extension and/or avens in the
roof close by.
When the water table fist began to fall in the cave, a new
swallet developed at the surface, close to the modern entrance. Once underground, its stream bifurcated. The larger part opened the Arête and Wire
Rift Passages, though not to their modern dimensions, whilst the smaller passed
into Maypole Series, joining the accessible passage there at the highest right
hand bend (going upstream). A tall but
very narrow rift was opened, the great potholes being later features.
Three gravitational streams now ran into the Central
Complex. One of these (Rocky Boulders
and Wire Rift Water) flowed through Boulder Chamber into the head of Everest
Passage where it undermined the phreatic honeycomb of the disintegration phase,
causing a great deal of collapse, which remains as the base of a long sequence
of deposits.
The second of these streams (Northwest corner of Upper
Traverse Chamber and Wire Rift) flowed into Cascade Chamber and through The
Fingers to join the first. It too caused
collapse all along its route. The
combined stream entrenched the floor of the lowest bore passage (Main Stream
Passage) but did not follow its old route through the Dining room into the
Rift. Instead, the flow broke laterally
into the Sewer. This lay at lower
elevation, causing a waterfall and the abandoned plunge pool which is now
Stalagmite Pitch. There was also entrenchment
between Plantation Junction and Gour Rift. At the cavers entrance to the rift it is twenty feet deep and thoroughly
choked with later stalagmite. The third
stream (September Series) precipitated much of the collapse there. Rock fall has been so heavy in this part of
the cave that little detail can be distinguished.
2. The Main Fill
Period. The rest of the history of
the cave is a sequence of alternating phases of erosion and various kinds of
deposition by gravitational waters. During the first half, deposition predominated and the cave was pretty
thoroughly plugged up to 640feet O.D. This period may be called the Main Fill. It had many phases and sub-phases.
In the central and south eastern parts of the cave, the
first phase alone was significant. Fast
streams from Boulder Chamber and Upper Traverse Chamber plugged the terminal
stream passage with an assorted mixture of silt, sand, pebbles and good sized
stones. Much of the material comes from
erosion of the north side of Stock Hill and places further north. It filled back to Plantation Junction and
then choked the entire
Everest and Main Stream Passage areas. Much of it can still be seen. For
instance it composes most of the west wall of Everest Passage: a few feet below
Plantation Junction, remains are jammed in the roof, eighteen feet overhead.
The filling of this phase stopped when the accessible parts
of the Railway Tunnel were about a third full. Two later phases of coarse stream deposition can be recognised in the
remains preserved along the north wall there. The central deposit has a few of the larger stone sizes (cobbles) which
distinguishes it from these above and below. At the close of the third phase, the further parts of the Tunnel were
fully choked also.
The streams thus clogged their first vadose route to Gour
Rift. As a result, they were spilled
through the abandoned phreatic short circuits into
and Mud Ball Chambers. From here to the
S.E. the floor gradient of the rift was evidently much lower than gradients
elsewhere in the cave. This permitted
sequences of gradation deposits to be laid upon it. The long series of phases and sub-phases of
the main fill is largely derived from analysis and correlation of two exposures
of the rift fill. One is seen in the
S.E. corner of Mud Ball Hall, the other is the climb up from the Dining Room to
Cerberus Hall. These two sections are
more complex than any others that have yet been described at sites deep within
Rhythm is characteristic of their sequence. Any one phase begins with the deposition of
the unsorted, coarse stream fill described above. Then follows a layer of small pebbles and
sand, indicating a reduction of rate of flow of the steam and, almost
certainly, its volume. The next is finer
still, of sand and clay only and this is followed by a layer of stalagmite.
Stalagmite sub-phases are common throughout the vadose
history of the cave. The evidence is
quite clear that, when they occurred, there was no proper stream flow in the
cave. The only water underground was
that permeating tiny cracks, becoming saturated with solutes in them and so
depositing calcite when it reached larger cave spaces. It must not be supposed that calcite
deposition by permeating waters goes on continuously in an air-filled Mendip
cave, spilling into the big stream channels if these are temporarily abandoned
by their erosive waters. Small forms may
be continuous but otherwise the record is again clear, in all of the caves
mentioned. Periods of vigorous stream flow
are periods when the permeating waters erode away the formations that they have
earlier deposited.
The depositional phase described is thus one of
progressively reduced stream flow, terminating in a cessation of flow and
general stalagmite deposition. The next
phase may begin with some vigorous erosion of the stalagmite by a renewed
stream. Coarse deposits follow before
there has been much clearance; then a reduction of flow, with sand deposition,
and so on. In the western half of the
rift, the record shows five of these gradational phases, the first correlating
with that which plugged up the
fill reached the low roof between Mud Ball Chamber and Cerberus Hall. It may be presumed that there were further
depositional phases in the higher parts of the cave, but no certain evidence is
preserved. At its peak, the main fill
extend to choke up most of Wire Rift (remains can be seen in two high false
floors there). There can have been
little open cave below.
The Extension Passage was choked. First by fill carried down the Warren Passage
which crosses it, then by the September Stream itself. The original phreatic passage (Continuation
Chamber to
junction) remains largely choked with coarse fill. In Extension Passage, the most striking
feature of the fill is the great depth of stalagmite layers. The best section can be inspected at the
entrance to Helictite Passage. A
stalagmite floor there is 36 inches thick; it rests on coarse fill burying an
earlier stalagmite. The floor was deeply
entrenched on the west side by a stream which then filled up to the top of the
extant passage (Cross Legs Squeeze). Continuation Chamber was also quite choked. A good stratigraphic section is exposed at the
climb down into it.
No other
cave has been so clogged with stream as St. Cuthberts. This is because it had a much larger
catchment basin during the Main Fill times, including a great deal of easily
erodible Mesozoic rocks.
(To be concluded in
the CHRISTMAS edition of the B.B.)
Editors
Note: lthough
it goes against the grain to have to cut the main article of this B.B., its
total length is such that it cannot at the moment be included in a single B.B.
without some production difficulties.
Caving Log
.for August and September.
Edited by
On the 3rd August, another incident occurred in Swildons
whereby a party was trapped because of the absence of ladders. Fortunately, the rescue was only a case of
Noel McSharry and Alan Thomas taking ladders to the top of the pitch.
On August 15, digging tools were brought out of the S.E.
Inlet Dig in Swildons by Alan Coase,
Lane
a recent breakthrough revealed 15 feet of passage which closes down to an
almost impossible choke.
Dave Irwin was at home in the Marble Hall area of St.
Cuthberts on the 22nd, with Mike Luckwill and Phil Kingston. A choke was pushed at the south end of Coral
Chamber, to a 50 foot pot which was choked at the bottom. Stones were dropped through holes in the
choke and travelled a fair way. A
further look at Marble Hall revealed a boulder ruckle with a very large passage
leading off.
On a trip to Trats
on the 28th, Chris Harvey climbed to a hole high up in the stream way, but
unfortunately slipped. He did not
describe the hole when writing up his trip in the Caving Log!
Tony Meadon and Mike Luckwill investigated the sump at the
bottom of Cone Chamber on 28th, which has earlier been reported dry. Digging
commenced with bare hands and the length of the passage increased by six feet,
revealing a promising dig.
Roger Stenner went down St. Cuthberts on September 2nd to
examine some of Don Coases surveying gear, and brought out his tripod for
cleaning. Roger also requests leaders to
ensure that old surveying stations have not moved or tampered with, as the new
surveys will not make them obsolete. They will also be of great value when other peoples surveys are tied
in.
On the 15th, Alan Thomas and Dave Irwin removed some of the
fill from the bottom of the 50 pot mentioned earlier, which is near Marble
Hall. Alan had some trouble climbing out
which, at the top, is reported to be extremely interesting.
On the 18th, these same two pushed a passage into a chamber
above Long Chamber Extension. A way on
can be seen but needs some enlarging. A
fine set of curtains were noted, also an erratic which grows upwards in the
stal. floor. On the very next day, the
passage was again pushed by Geoff Bull, Tommy Thomas, Pete Hudson and guess
who?, but was found to close down after about sixty feet.
On the 25th of September, Alan Thomas and Dave Irwin
inspected a hole in the roof of Pillar Chamber, near the three runged
ladder. They followed a passage or forty
feet into a reasonably sized chamber which was immediately above the chamber at
the top of Rocky Boulder Passage. Several other holes were noted on route. A hole in the roof of this chamber led to an even larger chamber with a
vertical rift on the left hand wall. This rift is apparently very well decorated. A bedding plane at the lower end of this
chamber seems to have possibilities of connecting with a bedding plane off Long
Chamber.
The Belfry Needs You Too!
What an excellent thing it would be if we had some tools at
the Belfry. If every member of the club
presented one tool, this would make a nucleus of over 170 tools which could be
used to improve and maintain the Belfry. Have YOU an old tool you could give the club? Perhaps your tool is old and worn; perhaps it
is bent or misshapen; perhaps you do not know what it is for or you have grown
tired of it. Perhaps you have two. Whatever its condition we should very much
like to receive it. Tools of every
description come in useful. Tools
donated will be kept under lock and key by the Belfry Engineer so that they
last. A list of all tools and their
donors will be published in due course sharpen chisels, reset saws etc. Please respond to this appeal if you can!
Mendip Sixty Years Ago
by Alan Bonner.
I recently bought a set of bound copies of The Climbers
Club Journal for the years 1898 1904, and, under the heading Kyndwr Club
Notes found the following report which I hope will be of interest to the
caving members.
At the close of 1902, two members, Baker and Bamforth,
accompanied by Mr. Morland and Dr.
Sheldon, went into eight caverns in the neighbourhood of Burrington and Cheddar
in
never been reached before and secured an interesting series of
photographs. A great deal of work
remains to be done at these two spots. Later on Baker and Bamforth joined a party led by Mr. H.E. Balch of
Wells a most persevering speleologist – who has put into practice some ideas
of his own with excellent results. His
speciality is excavation. At Eastwater,
on the top of Mendip, he sunk a shaft into a swallet and so discovered a great
cavern, through which a stream flows on its way to the water caverns of Wookey
Hole. On the occasion referred to, a
party of nine penetrated to a depth of more than six hundred feet below the
surface, and to a distance of two thousand feet from the cave mouth. The cave is exceptionally difficult. Its passages are so narrow as to be almost
impracticable, the explorers having, to give just one instance, to crawl
through an S-bend with a diameter of nine and a half inches. There are awkward vertical drops, with deep
pots lying in wait beneath them; long craggy canyons across slopes of 500 and
worst of all enormous accumulations of jagged rocks, through the midst of
which it is necessary to crawl and wriggle, carrying quantities of ropes and
other apparatus. Though it proved that
the Eastwater Cavern drains in to Wookey Hole, all attempts have so far proved
unavailing to explore the canals and water pipes that lie between.
At Wookey Hole, the upper galleries as well as the water caverns
were explored, with a view to finding the connecting links and since the Kyndwr
man left, Mr. Balch has cut a way into a new cavern of almost unparalleled
loveliness, which promises to lead on into the unknown region between the two
series of caverns.
The report goes on to mention the
is a lot of cave work to be done in
and many promising caves have hardly been touched.
The Kyndwr Club appears to have been formed in
earlier and, from the reports in the Journal referred to, were very active in
the caving and climbing fields.
Setts Mathematical Puzzles.
Pending an answer to the last problem, which will appear in
next months B.B., you may like to try this quickie.
One year, Ben decided to count the total number of pints he
served at the Hunters to cavers, so he kept a tally. On totting up the final figure for the year,
he noticed that it ended with a 4 and that, if he moved this 4 to the other end
of the number, the new number thus produced was exactly 4 times as big as the
one he had got. What was the number?