Site Name: Emmer Green (Hanover) South Chalk Mine
Jct. Peppard Road & Kiln Lane
Sub Brit site visit 2nd November 2003
[Source: Paul Sowan]
This is a report (with supplementary information) on a Subterranea Britannica 'fringe' event, organised and attended by individual members and led by Graham Old, of the local caving club, to whom we are most grateful. Access, arranged via the caving club, is via a 50 ft fixed steel ladder in a narrow vertical shaft below a locked iron cover.
GEOLOGY AND MINING IN AND AROUND READING
The whole of Reading and its immediate area is underlain at a shallow depth by the Upper Cretaceous Upper Chalk, usually covered by the sandy clays of the Lower Tertiary Reading Beds and, frequently, also by the Thames floodplain and terrace gravels. All these geological deposits have been exploited more or less intensively in opencast pits and, in the case of the chalk, also by mining. It has been suggested (Peake, 1913, and Shepherd, 1980) that there were prehistoric flint mines in the chalk at Peppard Common, about five kilometres to the northwest of Emmer Green, but a recent review of English Neolithic flint-mining (Barber, et al., 1999) has discounted this claimed mining site as unproven and in their view unlikely.
The Reading district, renowned for its brickmaking industries, has in common with extensive parts of north Kent, south-east London, and other areas such as the Sudbury district in Suffolk, numerous chalk mines worked below, and in conjunction with, brickfields. A percentage of chalk was added to the brick clays before firing, to counteract shrinkage. Whitaker, et al. (1872) noted that 'In brickmaking chalk is often used, being ground up and run into the other materials in a liquid state,' presumably meaning a chalk-water slurry, which would imply a need for a reasonable water supply and thus (before mains water was laid on) a substantially yielding well. Such a well, passing through 61 feet of Reading Beds into the Chalk, is noted by Blake (1903.)
Apart from Emmer Green, chalk mines (often if not always below brickfields) are known at various places in and around Reading (Carter, 1979.) The partial collapse of those at Field Road, Coley (SU 711728) in western Reading, caused extensive damage in the first two years of the 21st century, followed a year later by further ground collapses in Palmer Park (SU 737732) on the east side of the town. Further into Berkshire, chalk mines in the Newbury district, especially at Yattendon, have been investigated in recent years.
The chalk below the Emmer Green outlier is described in modern terms
(Mathers and Smith, 2000) as 'white soft and nodular chalk with abundant
flint seams' of the Seaford Chalk Member. The same authors refer to
the overlying Woolwich and Reading Beds, the Lambeth Group in modern
terminology, with the Upnor Formation at its base. The Upnor Formation
is a condensed marine sequence, usually less than 1 metre thick, containing
highly glauconitic, green, blue, and grey sands and clays, containing
fossil fish, oysters, etc .. with large irregularly shaped glauconite-coated
flint nodules and rounded flint pebbles [the Bullhead Bed] The old Chalk
sea bed is irregularly and extensively bored. The overlying clays are
generally of the order of 20m thick.
Photo:There is a marked difference in the floor level in some parts of the mine
Photo by Nick Catford
EMMER GREEN AND ITS AREA
Reading, from its commencement as a town on the river Kennet, has expanded over the years and now has within its boundaries parts of former Berkshire, south of the Thames, and Oxfordshire, north of the river. Former brickfields worked at what were once the edges of the built up area (and the chalk mines below them) have thus been built over as Reading expanded. This expansion of the built up area reached the Rose Hill brickfields site in Emmer Green in the late 1970s. Emmer Green (spelt Emmir Green in earlier sources) is some five kilometres north-east of the Caversham Bridge, and reached via the Peppard Road (B 481). From Caversham, this road ascends the hill beside Caversham Park, crossing a prominent river terrace half way up, and levelling out at Emmer Green, where there will be found a pond, two public houses, and a few shops at the heart of what is now a suburb of Reading.
The hamlet was too small to be noticed in The Parliamentary Gazetter
of 1840 - 41 (1842) and fell within Caversham parish. The entire parish
of Caversham had 1,069 inhabitants in 1801, and this had grown to only
1,369 (occupying 260 houses) by 1831. Most of these people lived in
Caversham itself, beside the Thames. Caversham, including Emmer Green,
was transferred from Oxfordshire to Reading in 1911.
Photo:The highest section of the mine, here the height is over 20 feet
Photo by Nick Catford
THE LOCAL DEMAND FOR MINERALS
Heavy soils on the clay outcrops, and acid soils on the gravels, probably called for the use of either raw chalk or of lime to lighten or neutralise them for agricultural uses. Both chalk and flint might well have been in demand for road-making, or simply for rendering rutted farm trackways between clay fields passable.
Clay for bricks and lime for mortar would have been in demand locally in the last four centuries or so, and chalk blocks and flint nodules are known to have been used as building materials at Emmer Green. Flints were probably also used on the roads.
Before the middle of the 19th century there was nothing but a few scattered houses, the settlement being no more than a hamlet on the edge of Caversham Park, where a large house had been built in the 1590s, and rebuilt in 1723. Several other large houses followed. A brick kiln appears first (Ormonde, 2003) in what records survive in 1645 (or 1654.) Apart from Caversham Park and local cottages, the greatest demand for bricks locally would have been for the erection of Old Grove House, St. Agnes (about 1650), Tudor Cottage (Surley Row (1540) and the White Horse public house in the 16th century. By the end of the eighteenth century, apart from the rebuilding of Caversham Park, bricks had been required for building Blenheim House (1770), Brickwall House, Caversham Grove (by 1761), Rosehill House (1791), and Springfield St. Luke. Brickwall House (early 18th century) stood beside the brickfields in the V between Kiln Road and Peppard Road, and is reported to have been erected for the brickyard foreman. It is now demolished, but there is a length of old brick wall built in rat-trap bond along part of the Kiln Road frontage which appears to be part of the old brickworks. The 19th century saw a rising demand for bricks, with the erection of the Black Horse public house (by 1830), Caversham Hill Chapel (1827), the Emmer Green Parochial School (1877), Grovehill House, and Hill House. Caversham Hill Chapel (1827) is brick, but with a Bath stone tower (the Kennet and Avon Canal, opened through to the Thames in 1810, allowed Bath stone to be brought into the district at a reasonable cost.) The first Anglican church (St. Barnabas (1898) at Emmer Green was an 'iron church' (now the church hall), the new brick church here dating only from 1925.
Interestingly, the older parts of St. Agnes (1650) are of brick and flint, with chalk block wall linings. A number of other local buildings include flint in their structures, such as the 17th century brick and flint house now number 46 Surley Row.
It is probably safe to assume that all of the older brick buildings
of Emmer Green used bricks from the local brickfield, and that the mortar
required was made from lime from the mines below the same source. It
is unlikely that it was economically viable to take bricks down to Caversham
and Reading itself before the advent of surfaced roads and motor lorries,
as these places had ready access to bricks from thriving brickworks
closer at hand with, in some cases, the options of rail or water transport.
Photo:Working face and a miners 'bench'
Photo by Nick Catford
THE BRICKFIELD AND MINES
Emmer Green's principal brickfield and chalk mining site was once generally known as Rose Hill. It lies in the V between Kiln Road and Peppard Road. Already by 1872 (Whitaker, et al.) southern and northern brickyards were referred to at this location. The land has now been built on, accommodating residential development, protected housing, and a scout hut, in Jefferson Close and Wordsworth Court. The site can be conveniently divided into the older southern part, and the newer northern part. There are three distinct accessible sets of mine workings, two of which (the northern mines) partially underlie the land managed by the Scout Association and are connected underground. These northern mines have two extant wide bricklined shafts, which are capped and locked. Harry Pearman (1982) has published sketch plans. One or both of the interlinked northern mines are known to have been used for the secure storage of documents by Reading Council during World War II, and two corrugated iron shelters, a brick-built stove and chimney, and tea-chests are said to remain below ground. One of the shafts reportedly contains timber staging, and one is said to be 70 feet deep. Pearman's (1991) description of the northern mines notes 'passages up to 20 feet high' and averaging 15 feet wide. He recorded that 'piles of chalk and flint debris cover much of the floors .. most of the flint has been left behind' (an interesting contrast with the southern mine.) No stepped working faces or mining 'benches' were noted. Dates and names on the walls were from the 1890s onwards.
The mine visited (numbered 2 by Pearman) is that in the southern part of the site, and closest to Peppard Road, with a shaft in woodland behind the sheltered housing. This is sometimes referred to as the Hannover Mine (the Hannover Housing Trust owns the site.) The shaft now used for access was rediscovered (Anon, 1977) in 1977 by earthmoving machinery in use on the surface. The site and mine was investigated in the following five years (Anon, 1982.)
The geological survey shows Reading Beds outcropping at this site. The overlying London Clay has been mapped nearby, especially at Clayfield Copse on the eastern side of Kiln Road.
Further information and pictures about this site continues here
[Source: Paul Sowan]