38
*
Company onPa large scale that concern having a programme of eighty bore- holes over the next four years. Many of these will be carried to a depth of as much as 2,000 feet. We agree that geologically the ground is favourable but stress that even if boring trials disclose the presence of new ore bodies much underground work will be required to establish their size.
171. Similarly at Hodbarrow, new ore bodies may be found immediately adjacent to existing workings. A relatively favourable area not yet fully pros- pected lies outside the present sea wall, but exploration by boring would be difficult since it underlies the Duddon Estuary and prospecting by cross- cutting would carry the risk of tapping large quantities of water. T
?
172. It is generally agreed by local experts and accepted by us that the prospects of finding any large body of ore in Furness, are exceedingly remote. Both in Cumberland and Furness, however, there exist certain small areas of ground not yet tested by boring where concealed Carboniferous Limestone may occur. While such areas cannot yet be considered as potentially ore- bearing, it might be worth while incurring a limited expenditure of money at some future date to obtain more precise geological information, although such ventures would have to be regarded as purely speculative. Meantime, however, it is most important that prospective areas are not ill-advisedly sterilised by surface development such as new towns, roads, or factories until the prospects have been examined more closely and, if necessary, explored by boring.
+
*{
י
173. We have obtained evidence of several attempts which have been made in recent years to locate haematite ore bodies by geophysical means. Generally, these attempts have been unsuccessful, although in certain instances; in the case of known ore bodies near the surface, some success has been achieved. It is felt, however, that the possibility of applying geophysical methods to assist exploration merits further study and research.
SOUTH WALES
174. From the beginning of the present century Llanharry Mine (10 miles west of Cardiff) has been the main source of haematite iron ore in this area, production having been as follows:-
31
1901 1902-7
TABLE XV
(tons)
HAEMATITE IRON ORE PRODUCTION-LLANHARRY MINE
1,200 1933 Inactive 1934
•
...
1910-25
...
820,000
1935
1926
32,945 1936
103,976 1941 144,251 1942 146,110 1943 229,938 1944
... 209,818
164,403
125,739
120,221
1929
206,871
1937
259,684 1945
104,646
1930
...
136,801
1938
...
188,135 1946
101,008
1931 1932
....
15,969 1939 60,954 1940
204,853 1947 233,743
95,152
175. We are informed that within an area of 237 acres at present being worked, the Company concerned state that they have ore reserves of 1.7 million tons fully and partially developed, with good prospects of further reserves in depth. In the next twelve months output is to be raised to a rate of about 130,000 tons a year.
FOREST OF DEAN
176. We have not examined this area in detail since the information avail- able suggests that for all practical purposes the iron porodeposits can be considered as exhausted. Most of the main areas from which the bulk
39:
IE
Summary
of production was obtained in the past are now flooded, and any attempt to re-open themmesbo carry out large exploratory Schemes would bet very costly. Geological evidence suggests that new deposits of any large size are unlikely to be found on see aunt ganod ti nava Jamli 2018 onde visdi reiluses of banhupen od fliw How brorobou Court to run a bod ein wen Bottsdicht is halimi i 177. In West Cumberland ore reserves equal to at least ten years' supply at the present rate of output are known. In one or two places in this area geological indications suggest that further exploratory work would be worth while. The estimate of about 13 million tons of reserves in the limited area being worked by the Glamorgan Hematite Iron Ore Co. in South Wales, is sufficiently large for confirmation of this estimate to be made and it is suggested a detailed resurvey of this field with, perhaps, additional exploratory work would be worth while.
}
anh bieuwen 15% krinko zaspu down slid suvor gen AT LEAD AND ZING ORES DV od tryim # gaituod
199100 ivno story nisidy ok. sub 1910 amor da 178. Ores of lead and zinc are usually associated in all the chief base. metal fields in this country, most of the lead mines having also produced zinc ore. The history of the mining of both of these ores and the position with regard to future possibilities, therefore, are similar and for present purposes it will be convenient to deal with the two minerals together
!
•
lazo
: 179. The chief districts which have contributed significant tonnages of these ores are listed below, together with estimates of total quantity of concentrates which have been produced since 1850. Figures are not avail- able for most of the mines prior to that date. In most of the areas mining (though generally on a much smaller scale) was in progress often for cen turies earlier, and the figures must therefore be taken more as an indication of the relative importance of the various districts than of the total tonnage of concentrates produced. Districts which produced less than 50,000 tons lead concentrates are not included.
TABLE XVI
PRODUCTION OF LEAD AND ZING CONCENTRATES SINCE 1850
·OFT}IKOR Lead on! Zinc-
fer Concentrates
Concentrates
(Average 75-80% (Average 45%
Pb)
Zn).
District
(tons)
Northern Pennines, Durham, Nor-
1,366,000
267,000
Derbyshire
thumberland, Alston Moor.
Flintshire and Denbighshire
Cardiganshire and Montgomeryshire
N.W. Yorkshire
Isle of Man
678,000
80,000
658,000
342,000
$479,000
151,000
30,000 EVOD
268,000
256,000
CornwallTM
Shropshire
Lake District
Devonshire
Page 65:
64.000
253,00085,000/
237,00000 20,000
183,000
165 of 6624,000
Wal
38,000
Approximate totals ⠀⠀
4,500,000
1,200,000 old
e do ke art ent
Jeneriks
40%
32
Mars
180. It will be seen that by modern standards lead-zinc production in England and Wales has been relatively small. Supposing each district could .be revived to the extent that production reached atrate corresponding to that at the height of lead mining prosperity in the UK sảy, 1850-1870, it would not satisfy more than about one quarter of present domestic requirements. Even in comparatively recent years, however, largely due to the success attending the relatively large-scale development of three mines (Mill Close, Halkyn and Greenside) domestic production of lead ore has made a significant contribution to requirements and fifteen years ago amounted to about 15 per cent or around 40,000 tons per annum in terms of metal content. Halkyn Mine suspended production in 1941 and Mill Close in 1944. Thereafter, Greenside Mine, with small contributions from wa few other mines in different parts of the country, has supplied the bulk of home-produced lead concentrates. Annual production has steadily de- creased since 1939, in 1941, it was 10,000 tons and is now (1948) about 3,000 tons, of which Greenside supplies over 2,500 tons. Valodi di do
of founa paroda
な
.
181. The decline in the prosperity of the country's lead and zinc mining industry dates from about 1880 and has been ascribed by the industry to various factors the chief of which are (i) taxation, (ii) the mstability of metal prices, (iii) the influence of competition from lead mining undertakings overseas. While these reasons may have had an important influence on the decline, it is usually accepted by responsible authorities today that the richer and more accessible deposits have been largely exhausted. Further- more, present-day conditions are not usually sufficiently attractive to en courage mining enterprise to finance the search for new ore bodies, which, in general, would mean exploration at greater depth and with less chance of success than GITE QERORGUL IN DE OALA TO Casi
in OTE
Resources M) noite
וי
182. Apart from a few relatively minor occurrences referred to below, it can be stated that there are no proved resources of lead and zinc ores of importance in any mineral district. A few attempts are at present being made, no doubt encouraged by the present high metal prices, to re-open small mines with the object of carrying out limited exploration and develop- ment. Some lead ore is being obtained as a by-product of fluorspar mining in West Durham and in Derbyshire. So far as the future is concerned, however, any real attempt to increase production of lead and zinc ores would have to be preceded by an extensive exploratory campaign with the object of discovering and developing large new ore deposits, if they exist. While there are geological and other reasons indicating that such a campaign would have a reasonable chance of success in specific cases, the work could not be regarded as other than highly speculative. The main evidence available at the moment which would be helpful in planning such prospecting campaign and which at least draws attention to not unpromising geological factors, has been obtained by the Geological Survey during the course of recent surveys in the mineral fields, and by other leading authorities, on
es on which evidence has been presented to the Committee. (See especially Dunham, K.C., Trans. of the Institution of Mining and Metallurgy, Vol. liii, p. 181, 1944.)* *
a
i
MensTXO OM JEA
183. The position of the various mineral districts is briefly reviewed below.
NORTHERN: PENNINES.
Proved Reserves, dideng. You brhub bawio
:184. Exploration carried out in 1938-1939 proved the existence of about 100,000 tons of 10 per cent lead ore at Coldberry Mine, near Middleton-in- * See also" Geology of the Northern Pennine Orefield, Vol. 1, Mem. Geol. Survey, 1948. (H.M.S.O. Price 17s. 6d.)
41.
A
Teesdale. A company has recently been formed to operate this mine. Else-
lead
are known although small tonnages of zinc ore am economic importance
Mine, near Alston (about 54,000 tons with 8.75 per cent. zinc) and at Etters- gill Mine, near Middleton-in-Teesdale (25,000 tons with 10 per cent. zinc).
Probable Reserves
185. At Sipton Mine, East Allendale, which was closed in 1943, a reserve of lead ore has been indicated on the continuation of Esps vein, but the exact quantity would have to be determined by further development. Similarly, at Rotherhope Mine, near Alston, recently closed, probable reserves exist, but an estimation of the exact quantities and grade is not possible.
Prospects
186. There still remain large areas in this district where the Great Lime stone, which is the favourable horizon for ore deposition, is accessible but is as yet unexplored. Dr. Dunham, in the paper referred to, regards an area of about 1 sq. miles near Kilhope, between Nenthead and Allendale, as the most promising, since it is situated directly between the large mineralised fields of Alston Moor and Allendale which have been so productive of lead and zinc concentrates in the past. Two further areas lie between Weardale and Nenthead and between Rookhope and East Allendale, neither of which, however, is as promising as that near Kilhope. All of these areas should be treated as units for the purpose of any exploratory programme. More than one mineral owner is involved.
DERBYSHIRE
2
187. No reserves of lead or zinc ore of economic importance are known, and the history of this district, with one important exception (Mill Close), has shown that all the mines have been relatively small, and that the area was approaching exhaustion by 1860. The development of Mill Close between 1920 and 1944 showed for the first time that mineralisation extended deeper than was orginally believed. Similar geological conditions to those existing at Mill Close are known to exist in certain parts of Derbyshire and thus a potential unexplored area of ground exists at depth where new deposits of lead and zinc ores may well be discovered. Generally speaking, however, such exploration would be costly, and, as in the case of the Northern Pen- nines, attempts at exploration in future would have to be on a large scale and backed by ample resources.
FLINTSHIRE AND DENBIGHSHIRE
188. No proved reserves are known in this area. So far as future prospects are concerned, however, it is generally agreed that the further development of Halkyn Mine holds promise. This mine was one of the three largest pro- ducing lead mines in this country, and operations were suspended in 1941 owing to the exhaustion of most of the ore in the ground developed. The existence of other veins in this area is known, however, and there are reasonable prospects that the extension of workings of Halkyn Mine south- wards would reveal the existence of new ore bodies. We understand that ex- ploration has recently been restarted by Halkyn District United Mines, Ltd.
189. Although strictly speaking not in this district, mention might be made of Parc Mine, Llanrwst, closed during the War, but which has been proved still to contain a small tonnage of low-grade lead and zinc ore. There are some prospects of discovering further deposits in Pageground immediately adjoining it. Trecastell Mine, also in this area, has recently been re-opened.
42
33
CARDIGANSHIRE AND MONTGOMERYSHIRE
190. It hasapeerbestrated that in two or three mileage this area reserves of zinc ore have been proved from which about 30,000 tons of zinc (metal) could be recovered. The mines are now flooded. Apart from this there are no known reserves.
1
:
191. Generally, the prospects for new discoveries of importance are not very promising and on the whole are better for zinc than for lead. The largest areas which offer the best chances are (i) Frongoch, (ii) Cwmystwyth, (iii) the Rheidol Valley and (iv) Bryn Yr Afr. If exploration of these proved successful, development on an economic scale would probably depend on the extent to which mines could be worked in groups based on a central plant.
LAKE DISTRICT
192. Apart from ore developed in Greenside Mine, which is only likely to be sufficient to maintain operations for another year or two, there are no proved reserves. It is stated that probable reserves of lead ore exist in Threlkeld Mine but no estimate is possible of the tonnage. Similarly reserves of zinc ore are reputed to exist in Thornthwaite Mine, but here again no information is available. It is unlikely that either of these mines can be developed on a large scale. Elsewhere in the Lake District prospects for the future are unfavourable. davatse ele na mug w
:
N.W. YORKSHIRE
193. There are no known reserves in this area, and generally speaking, with one or two local exceptions, geological evidence suggests long-term prospects are not favourable.
;
ISLE OF MAN !
194 So far as is known, the lead and zinc veins in the Isle of Man have been exhausted and the prospects of new areas being discovered are not promising.
CORNWALLA
195. There are no known reserves but it has been submitted that the re-opening and development of one or two small mines might be successful. From the long-term point of view, however, it is unlikely that lead produc- tion could be resumed in Cornwall on an important scale.
SHROPSHIRE
196. So far as is known all the mines have been worked out and the prospects generally are unfavourable.
DEVONSHIRE
197. The record of past production in this area does not suggest that it could be regarded as of any importance from the long-term point of view.
Summary
198. There are at present no important proved resources of lead and zinc ores in England and Wales, and if the industry is to be revived it will be necessary for new prospecting and exploratory work to be put in hand. We believe that there are areas in the country where favourable results might be erected of 662