CAB129-36 — Page 59

34

148. Sussex and East Kent. The gypsum of Sussex and East Kent occurs in the Purbeck Beds (top of the Jurassic) which come to the surface as three small infiers through the overlying Lower Cretaceous Strata on the crest of the Wealden anticline about midway between Tunbridge Wells and Hastings.The Purbeck Beds consist of shales and thin limestones with, in the lower part, beds of gypsum.

A

149. The present workings are confined to the middle inlier situated a mile from Mountfield near Robertsbridge. Four seams are known. section is as follows:

29

TOP SEAM

sochhet

15 FT. SEAM

MIDDLE SEAM

frolmlue BOTTOM SEAM Pand

08

ft.

Gypsum grey, with white mb patches, 21

945

Gypsum grey; ital

5

DOA

Shale,

4

54

6

limestone. ili veizo so

14 a

Gypsum grey with some

shale and limestone.. Shale.

Gypsum, with shale and

The Top and Middle (sometimes known as Lower) seams have received most attention. The Top Seam was worked longwall but pillar-and-stall method has now been adopted.

"

150. Robertsbridge mine has recently been mechanised and re-organised for a rate of production of 400,000 tons per annum. The reserves of mineral have not been precisely estimated but are understood to be well in excess of 10 million tons.

up

16 no calor 151. Cumberland. An important source of supply at the present time is the Cocklakes Mine about 5 miles S.E. of Carlisle, where there are 2 beds of gypsum each about 8 ft. thick separated by 5-7 ft. of anhydrite and dipping northwards at a small angle from an old quarried outcrop. The annual rate of production, decreasing in the war years, is now back at the 1939 level. There are believed still to be large reserves, principally in the upper gypsum bed..

152. The one other active mine in Cumberland is in the Long Meg area near Lazonby where there are two gypsum beds separated by anhydrite at much the same geological horizon as that at Cocklakes, although the gypsum here has thinned down to about 5 ft. in each bed and the anhydrite thickened to 9-10 ft. No positive estimate of mineral reserves is available, the only indication being that in the Geological Survey Memoir* the possi- bility of the gypsum and anhydrite strata continuing to the north and south of the present mined area is mentioned, but with a predominance of anhydrite down dip.

..

153. In West Cumberland, gypsum was formely worked with anhydrite near St. Bees Head (Barrowmouth). The area likely to carry workable gypsum covers about 5 square miles and in the old Barrowmouth mine the thickness of the bed is said to have been 15 ft. and even 25 ft. in places. The anhydrite is present in considerable quantities, however, and the degree of inter-mixing is such as to reduce the importance of the area as a source of gypsum for plaster-making owing to the difficulty of separating the

PSpesialReyfri62Vol. III, Gypsum and Anhydritege1838 of 662

65268

35

B 4کا کیا

minerals in mining. We are advised that B. & A. Collieries Ltd. recently carried out some exploratory boring in this area. The National Coal Board is now engaged in boring at St. Bees Head with a view to proving the

100 coalfield to the south of Whitehaven and while additional information on the presence of gypsum and anhydrite may be revealed, the Northern Division Authorities of the Board do not consider it would be possible to work the coal and gypsum conjointly. EDEL

MEST

berentis quini, sibbing set of brailing sin avidiow Insconq siff QUI 154. Westmorland. In the Kirkby Thore area two mines are at present working; that at Stamp Hill has been much extended during the war years. There are 4 gypsum beds here aggregating about 12 ft. of mineral, the top bed being 6 ft. thick and the others each about 2 ft. The extent of these beds has not bear closely defined, but it is known that on the margins of the working district anhydrite progressively replaces gypsum and sets a definite limit to the exploitable area in the direction of the northwards dip.

stude

155. Staffordshire. The Fauld district, about 2 miles NW of Burton- on-Trent, has been famous for centuries past as a source of alabaster. The mineral is found in the horizon known as the Tutbury Gypsum Bed and is usually 8-10 ft. thick. In view of the extremely limited amount of geological information which exists in this district, it is not possible to comment on the gypsum resources.

ink caure (ismod to avond zeruança) SILSIM Ona goT srT madelig bo Hagnol badow eww fansé qul ofT · obnesla wom Minor Areas

.bsigobe nood voo ead bodism 156. (a) Derbyshire. The Tutbury gypsum horizon carries workable mineral here as in Staffordshire, although there is now practically no pro- duction and the area is of little importance. The mineral in the form, of alabaster has been quarried extensively from a 10 ft. thick bed

bed in the Chellaston and Aston districts, a few miles S.W. of Derby. There appears to be no information as to the extent of the deposit which is near the surface and broken into pillars by infillings of glacial drift, da smile 29Malfood w bas sinted. To a 52 gd Lotsvagon Maid 3 & woods ifoso muzeqve ho 157. (b) Somerset. Recent boring and excavation at Hurcot, near Somer- ton, have shown the existence of some 6,000 tons of gypsum, and indicate that the deposit may extend considerably beyond the proved area: The mineral occurs in bands of varying thickness and is expected to amount to about 25 per cent. of the quarrying face when fully opened up. No market- able production has as yet been obtained, and there is an overburden which is large for quarrying but too thin for mining proper. The deposit is not well situated for economic distribution.

E MINE AND NORMI 18 howaid: asd mur mureq.2

· 158. (c) Other Occurrences. Gypsum has been worked in a small way in the Yate district of Gloucestershire, in Dorset, and in Leicestershire (in the area adjoining the main Nottinghamshire field). The reserves of mineral in these areas are not believed to be important by present-day standards of production.

qib n vob gráuvdná

159. The presence of gypsum has also been proved in the Long Fryston area of the North Riding of Yorkshire, and in S. Cumberland and Furness.

Summary

i

160. We conclude that the resources of gypsum in the U.K estimates of which exceed 100 million tons, are such as to ensure all foreseeable demands for many years.