Surrey's Extractive Industries
Total Page：16
File Type：pdf, Size：1020Kb
SURREY’S INDUSTRIAL PAST 7 EXTRACTIVE INDUSTRIES [Page 4] Chapter 2 SURREY’S EXTRACTIVE INDUSTRIES Extractive industries — the digging of chalk, clay, sand English Channel and northern France, and a ridge of and gravel, flint and building stone, fullers earth and high land ran across what is now London. A tropical iron ore — and the lime works, brick works, iron and swampy river delta, in which dinosaurs lived, extend- glass works which depended on them, have been the ed into Hampshire and material washed into this area most widespread of Surrey's industries. Most are now became the Hastings Beds and, overlying them, the extinct. The Wealden iron and glass industries have Wealden Clay. The sea overran the Weald and sedi- long since disappeared and at the end of the twenti- ments which settled on the bottom became our pre- eth century stone quarrying, fuller’s earth and chalk sent Lower Greensand, Gault Clay and Upper Green- extraction are about to join them. Environmental con- sand. The Chalk came next, laid down in seas far from siderations limit sand and gravel digging and even land as a white calcareous mud. Chalk as we know it brick works are declining in number. Despite this, dis- today is composed mainly of calcium carbonate de- turbed ground, lakes, tracks, place names, workers’ rived from the calcite plates which protected micro- cottages and even whole villages will for long provide scopic planktonic algae, the rest being made up of a reminder of these once significant industries. Count- microscopic fossils or shell fragments. The Upper Cre- less small pits, ponds and scars on the landscape date taceous period, during which the chalk was laid down, back as far as history. ended 65 million years ago. The Rocks In the Tertiary era which followed, the Weald was on the fringe of the earth movements which produced Surrey encompasses part of the Weald and part of the the Alps and the Himalayas. The chalk rose from the Thames valley. At the end of the Jurassic period, sea as a dome or anticline, over the present Weald, about 140 million years ago, a trough filled with fresh and a complementary trough or syncline formed in water covered what is now south-east England, the SURREY’S INDUSTRIAL PAST 8 EXTRACTIVE INDUSTRIES what became the Thames valley. The land was erod- sold for housing development. A novel way of win- ed, principally by water, and the softer clay for- ning gravel has been adopted by the Thames Water mations were eroded most. In Surrey this produced, Authority by digging out the bottom of the Queen from north to south, the line of the North Downs, a Mary reservoir, doubling its capacity and financing Gault Clay valley, the Lower Greensand ridge, the the work by the sale of the gravel. Wealden Clay lowlands and the Hastings Beds of the In the west of the county, near the Hampshire border, High Weald. the river gravels of the Blackwater valley have been [Page 5] extensively worked. There is now an almost continu- Strata laid down in the Thames valley during the ous series of flooded pits, mainly preserved as nature Tertiary period include the sands, loams and clays of reserves. The last extraction in this area was near the Thanet, Woolwich and Reading beds, the London Tongham, where a new pit was opened to provide Clay, a thick uniform deposit laid down in a shallow ballast for the building of the Blackwater Valley Relief tropical sea, and the sands and gravels of the Road in the 1990s. Claygate, Bagshot, Bracklesham and Barton beds. Further south, the Farnham area was well dug over Apart from the London Clay, these were not laid for sand and gravel by the end of the nineteenth cen- down over the whole Thames valley and, unlike the tury. Today the gravel has been largely worked out strata of the Weald, they do not come to the surface but sand extraction from the Lower Greensand con- in any simple pattern. Some of them would once have tinues apace with applications for new licences being covered the eroded surface of the Weald, but little made in both the Wey valley to the west of the town remains because of later erosion. There are also su- and the Runfold area to the east. The earliest work- perficial ‘drift’ deposits, formed locally by erosion and ings were small pits in the river gravel terraces ex- deposition in the last million-and-half years. These tending upwards on the north and south valley sides. include the river gravels of the Thames and Blackwa- There is some evidence for prehistoric use for flint ter valleys in north and west Surrey, deposited on a implements, particularly to the north of Farnham at series of terraces, and the thin layer of Clay-with- Caesar’s Camp. Later uses largely revolve around bal- Flints, produced by weathering of the chalk, which last for concrete making and there are small numbers caps the North Downs. The flint itself originated in of houses in the town built of this material in about particles of silica which recrystallised in layers in the 1900. chalk as it formed. [Page 7] [Page 6] Flint, Chalk and Lime: Industries of the North Downs Sand and Gravel in North and West Surrey The minerals of industrial importance in Surrey from FLINT the younger deposits north of the Downs are almost entirely sand, gravel and clay, which sometimes alter- Flint was used to make tools in prehistoric times but nate over short distances. While the digging of clay is most obvious in the landscape as a building materi- for brick-making has long since ceased in the area, al for the picturesque houses and walls of the gravel extraction has continued on an ever increasing chalk districts. Flints were picked from the fields and scale up to the present day at Thorpe, Hersham, and knapped to expose the shiny black interior for visual Staines Moor. This is not welcome to the local popula- effect. Unknapped flints have been widely used in tion and there is generally opposition to the opening road building, and ‘hogging’ — flint fragments em- of new pits. bedded in a clay matrix, found in Tertiary deposits — Worked-out pits have been treated in various ways. is still used for the foundations of drives and car The best-known ones are the flooded pits incorpo- parks. Pits are still being dug for hogging near rated into the Thorpe Theme Park. Another pit, close Warlingham. to the Thames, has been converted into the Penton CHALK Hook Marina. Others have remained dry and have been filled with refuse and others have remained dry Chalk has been used for improving acid soils since and empty and have been landscaped, as at Heather before Roman times. It was dug from bell pits or more Gardens in Windsor Great Park. At Englefield Green, elaborate workings known as dene holes. Narrow local people were allowed to help themselves to shafts were dug through the clay on the crest of the scouring sand for many years until the deposits were Downs into the chalk below. When structurally worked out for the building of the adjacent Royal Hol- sounder chalk was reached at about 60 feet down the loway College. The resulting pits were landscaped as shaft could be extended horizontally, sometimes part of a botanical garden but the site has since been forming elaborate chambers. When it became im- SURREY’S INDUSTRIAL PAST 9 EXTRACTIVE INDUSTRIES Gravel extraction at Weydon Lane, Farnham, early twentieth century. practicable to work a pit, another would be started [Page 8] alongside and so clusters of pits developed. Dene LIMEKILMS holes are common in Kent and occur in east Surrey. Farmers on clay soils even back to the sixteenth cen- There are no open ones in Surrey and they are gener- tury would have their own small limekilns. The name ally difficult to locate, though occasionally alarming Firsfreld or Furzefield may indicate the presence of a craters open up to reveal their presence. kiln because furze was used as fuel. In the type known Lumps of chalk were cast onto fields at the end of as a flare kiln, the chalk was constructed as a dome autumn and left to weather over winter, releasing over the furze or brushwood and fuel and it would calcium carbonate and other trace minerals to the take 24 hours of burning to convert it to quicklime. A soil. The process is known as marling, though the model of such a kiln can be seen in Guildford Museum term is often used loosely for substances other than and it is still possible to find remains in the field. chalk. It did much to improve agriculture but was in- Farmers who lived some distance from the North efficient as chalk needs to be spread as a fine powder. Downs had chalk carted to them but when chalk pits, It will then quickly neutralise acid and cause clay par- equipped with large industrial kilns for limeburning, ticles to coagulate, allowing air into the soil and im- were opened in the nineteenth century farmers were proving drainage, and it will make calcium easily avail- able to dispense with private kilns. The expansion of able to plants. The modern method is to crush and the building trade in the eighteenth and nineteenth dry the chalk into a powder mechanically but it was centuries stimulated the limeburning industry. Brick common practice in the past to apply quicklime to buildings need mortar to bind the bricks together and fields.