Salt content of brine.
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dows of galbimo viloma TABLE XVIII. brommouss cals W JED
XVIII®d: Page 73 of 662PRODUCTION OF SALT IN 190 73 of 6622 amriell
918 eidghieronim
Gintben. Bilanobrir as Östle all bulair blonia wasiojuq sklz di-
(tons)
Cheshire Lancashire Durham S. Staffs. Worcester: Isle of Man
...
...
...
...
winca ora hi
*Salt in Brine
Dried Salt
voleb godtiw bas Rock Salt Total sw
!
1,858,667
665,438
39,997
2,564,102
316,066
316,066
72,544
79,946
152,490
72,274
72,274
33,321
33,321
1,046
1,046
Resources
2,247,277
852,025 39,997 3,139,299
· Other than for Salt-making.my
Ask quesmob to readin... odt
217. The chief producing salt fields of Great Britain are:
bomson
(a) Cheshire (with extensions into Shropshire). This is by far the most
important.
(b) Lancashire.
(c) South Durham-N. Yorkshire (The Teeside area).
These are dealt with in this order below, followed by shorter descriptions of several occurrences which are known, and from some of which smaller quantities of salt are obtained.
-
I
JULAnon
CHESHIRE-SHROPSHIRE o vi: arton toit
218. The major salt field of Great Britain is found in these two counties and occupies a broad syncline stretching some 50 miles southward from Wilmslow in Cheshire to Wem in Shropshire. It contains two salt beds. the Top and Bottom Beds, or "Rocks", separated by the Middle Marl. The salt beds reach their greatest development near Northwich where a thick- ness in each of at least 90 ft. has been recorded. Brine is drawn from the whole salt formation through bore-holes.
!
219. The total area underlain by salt has not been defined, but it is known to amount to many square miles. Quite recently extensions have been proved in the neighbourhood of Mobberley by test bore-holes sunk in connection with the New Towns Act.
:
220. At the Meadow Bank Mine of I.C.I. Ltd., near Winsford, rock salt is worked at a depth of 450 ft. from the lowest 15 ft. of the Bottom Bed · which contains less marl and for this reason is the only part mined. This is the only mine now operating in the U.K.
LANCASHIRE
221. Salt deposits occur at Preesall, near Fleetwood, and in Walney Island, near Barrow-in-Furness, where they have been proved by boring..
222. At Preesall, the salt formation occurs as a lens about 1,500 yards across and 300 ft. thick at its maximum. It has been worked underground, but is now subject to extraction solely by brine-pumping. An attempt to work the Walney Island salt was made many years ago (circa 1895) but was unsuccessful... The salt in this area probably occurs in two lenses, one of which age beanofe6orded as up to 237 ft. thickage saltofs Gusually mixed with marl. The top of the deposit is at a depth of around 500 ft.
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bstalosi. Inone A
SOUTH DURHAM-NORTH YORKSHIRE bankroom Page 7400P DURHAM NORTH YORKS Page 4 of 662
ecoupage 74 223. In the Fees estuary, an area of some 20 square miles around Billing. ham and Middlesbrough is underlain by salt deposits overlying anhydrite. The latter mineral is worked underground by Imperial Chemical Industries, Ltd., but the salt is obtained to the east of the anhydrite mine by brine- pumping from a bed having an average thickness of about 100 ft) to zabol
224. Important discoveries of salt beds at depths of over 3,500 ft. have the North Riding of Yorkshire as a result of an oil-prospecting bore-hole, which also proved potash salts at various depths. A nearby bore-hole made recently expressly in search of potash-bearing brine and s solid- potash salts is understood to have confirmed the earlier findings of common salt and potash minerals (para. 209).
been made.
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Salt is also known to occur in the Market Weighton and Barlow districts. 1 botol reed ner som od Uslab yuo ut
Ustab ta ut som bj ontury ich ni ow Minor Areas alt bombest viivide zain
ditos,
koby lo abgunan vaeth (an at [xiom - 1) anos 600 STAFFORDSHIRE
Hutong Jaunch no nody quunto 225 The salt industry is here located at Stafford Common, on the northern outskirt of Stafford, where brine is pumped from bore holes. The salt strata are thin and marly in character, being a southward marginal continuation: of the main Cheshire beds from which they have been separated as the result of folding.mob, derne) oder black su to pray vodoo adi akawa intædio
WORCESTERSHIRE
sigui au hod
226. Droitwich has long been a centre of salt production and rock salt was mined at Stoke Prior in the latter part of the 18th and early 19th centuries. The pumping of brine has been discontinued at the Spa itself for amenity reasons and concentrated at Stoke Prior: Oro mom TaG JANT
UNO OTHER AREAS
227. Salt is being produced in a small way in the Isle of Man and in 'Somerset. ARY
Summary
:
228. The reserves of salt present in the U.K. is a matter of considerable speculation, but they have been estimated by the late Dr. R. L. Sherlock of the Geological Survey as at least 15,000 million tons. It will be obvious that reserves must be very large because about 1 ft. of salt over a square mile is equivalent to over one million tons, and the Cheshire salt-bearing ground is known to cover more than 20 square miles with two of the main"; beds having a thickness in places of at least 90 ft. Similar arguments sug- gest that in N. Lancashire and Durham ample reserves still exist; further i more, the discovery of potash-bearing salt beds and brines in N.E. Yorkshire points to a new and large supply of salt becoming available should it be feasible to develop this source of potash as a major contributor to the national needs.
ME DHION AD UQMAN HOE WE SINGA
رو
יו.
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229. It is reasonable, therefore, to draw the conclusion that in the three main producing areas alone ample workable reserves exist for all reason- able and foreseeable needs, and that, in addition, large reserves of salt are present in the other areas, indicated. ons bene pavitain, they
We love that rol jud ssl sdf Lomi to Kuni pre vol ze (013 stegi ulimi TIN AND TUNGSTEN ORESTDIEGO BAT nato a wift to echvotales wit to WORE TE WATOTO COLOR Bogn
VA
24.
230: The resources of the tin mineral, cassiterite, and the tungsten minerals,
wolfram and scheelite lig almost entirely in Cornwall and the adjacent parts of Devonshires the ores 8ccurring in veins ("lodes "connected with thei
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38
intrusion of the several granite masses in those Counties. A small isolated occurrence of both the tungsten ores occurs at Carrock Fell, Cumberland, which hap been worked in a small way and was re-examined by the Ministry of Supply during the last War.
Mulo lytsboo
231. Up to the middle of the Nineteenth Century many of the tin-bearing lodes of Cornwall were also worked for copper ore, especially in their upper parts, and with contributions from certain other occurrences (in Anglesey, Cheshire and the Lake District) contributed the bulk of the world supply. of copper. Since then copper mining in the south-west of England has ceased and the chief metalliferous minerals worked have been tin and wolfram ores; there is little prospect of copper mining being revived (paras. 113 to 116).
-232. The history of tin mining in Cornwall is generally well-known, and we do not propose to trace it in any detail. The area has been worked for many hundreds of years. Mining activity reached its zenith in the last century, when an annual production of around 10,000 tons (tin metal in ore) was attained from about 1860-1870. At that time this figure represented 40 per cent. of the total world output. Since then the decline in production on average has been continuous, the overriding reason being the gradual exhaustion of the known and more accessible deposits. In comparison with alluvial workings in other parts of the world the Cornish tin mines have gradually become high cost producers.
TABLE XIX
TIN ORE PRODUCTION-DEVON AND CORNWALL
(tons-in terms of metal content)
1938 1939
...
1,999
1943
1,359
1,738
1944
1,389
1940
1,619
1945
993
1941
1,508
1946
849
1942
1,364
*
1947
802
(For production figures prior to 1938 see page 11)
233. The number of tin mines operating in Cornwall and Devon reached a maximum of 230 in 1874. At the beginning of the twentieth century the number had been reduced to 100, and in 1938 it was 4; only two mines of importance are in operation to-day. Present production of tin from Cornwall is of the order of 800 tons (metal in ore) per annum, equivalent to between 2 and 3 per cent. of current domestic consumption. The annual value of the output at present-day prices is approximately £450,000.
234. Wolfram is the main tungsten ore found in this country. At present only one small wolfram mine is working (in Cornwall) although a little wolfram is obtained from time to time as a by-product in the tin mines. With one or two exceptions it has only been in times of war that mines have been opened for wolfram primarily. The domestic deposits of this mineral are generally relatively small and not able to support anything more than small mines for any length of time. The large but low-grade deposit of wolfram (also containing some tin) at Hemerdon, near Plymouth (para. 250) may be an important exception, particularly in view of the existence of the large and modern treatment plant erected by the Ministry of Supply during the 1939-45- War, and because the deposit can be worked opencast on a large scale.
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