TRM3 Other Minerals Kent County Council Contents 1 Introduction 1

Home , Brickearth, Funton, Geology of Kent

Kent Minerals and Waste Development Framework

Planning for the future of minerals and waste in Kent

Evidence Base for the Minerals and Waste Core Strategy Strategy & Policy Directions consultation

Minerals Topic Report 3: Other Minerals

May 2011

TRM3 Other Minerals Kent County Council Contents 1 Introduction 1

2 Other Minerals 3

3 Clay 5 3.1 National Policy 6 3.2 Brickearth 7 3.3 Brick Clay 10 3.4 Engineering Clay 14 3.5 Specialist Uses 15

4 Chalk 17 4.1 Cement 17 4.1.1 National Policy 17 4.1.2 Cement 17 4.2 Agricultural Lime 18 4.3 High Purity 20

5 Silica Sand 24

6 Energy Minerals. 25 6.1 Coal 25 6.1.1 East Kent Coalfield 25 6.1.2 Coal Bed Methane 26 6.2 Oil 27 6.3 Natural Gas 29

7 Natural Building and Roofing Stone 30 7.1 Policy 30

8 References 34

Appendix 1 1

Appendix 2 2 Kent County Council TRM3 Other Minerals Contents TRM3 Other Minerals Kent County Council 1 1

1 Introduction Introduction

1.0.1 This topic paper considers all the economic minerals(1) in Kent that are not exploited for construction aggregates. Consequently it is a report that covers a wide variety of minerals and an equally wide variety of potential uses.

DA ME GR TH SW

CA SE TM MA DO Solid Geology of Kent Lenham Beds Bagshot Beds Claygate Beds London Clay Superficial (Drift) Deposits of Kent Blackheath / Oldhaven Beds AS Landslip Woolwich Beds TW Blown Sand Thanet Beds Marine Beach / Tidal Flats Bullhead Bed Storm Gravel Beach Deposits Upper Chalk SH Marine (/Estuarine) Alluvium (Clay Middle Chalk (Sand (Sand & Gravel) Melbourne Rock Lower Chalk (Glauconitic Marl) Calcareous Tufa Upper Greensand Alluvium Gault Clay Dry Valley & Nailbourne Deposits Lower Greensand Folkestone Beds Peat Sandgate Beds Brickearth Hythe Beds Undivided Flood Plain Gravel Atherfield Clay 1st Terrace River Gravel Weald Clay 2nd Terrace River Gravel Sand in Weald Clay (/Sandstone) 3rd Terrace River Gravel Large 'Paludina' Limestone 4th Terrace River Gravel Small 'Paludina' Limestone 5th Terrace River Gravel 'Cyrene' Limestone 1st/2nd Terrace River Gravel Clay Ironstone 2nd/3rd Terrace River Gravel Undifferentiated Clay & Limestone 4th/5th Terrace River Gravel Hastings Beds Taplow Gravel Upper Tunbridge Wells Sand Boyn Hill Gravel Upper Head Cuxfield Stone Coombe Deposits Lower Grinstead Clay Ardingley Sandstone ¯ Head Brickearth 0 5 10 20 Lower Tunbridge Wells Sand Head Brickearth (Older) Kilometers Tunbridge Wells Sand Head Brickearth 1st Terrace Clay in Tunbridge Wells Sand Head Gravel (C) Crown Copyright. All rights reserved 100019238, 2010 Grinstead Clay Plateau Gravel Wadhurst Clay Clay-with-Flints Sand in Wadhurst Clay Sand in Clay-with-Flints Geology of Kent Ironstone in Wadhurst Clay Disturbed Blackheath Beds Ashdown Beds

Source: British Geological Survey

1.0.2 The geology of Kent consists of the solid geology(2) that forms the bedrock to the county and is responsible for the major landscape features such as the North Downs (Chalk), Greensand Ridge (Hythe Beds) and the High Weald. This is overlain by the superficial (or drift) deposits(3) that form an intermittent veneer over the solid geology.

1.0.3 Kent once had four principle industries based on the wealth of minerals in the County, construction aggregates, coal mining, brickmaking and cement. The construction aggregate industry remains a force in the County but the other three have declined in the latter part of the 20th Century. Coal was mined in East Kent, brickmaking was based on the various clay deposits and cement on the chalk horizon.

1 Appendix 2 Glossary. 2 Appendix 2 Glossary 3 Appendix 2 Glossary 2 Kent County Council TRM3 Other Minerals

1.0.4 These industries have substantially declined to the point where there is only one brickworks remaining, one dormant and one for sale. There is one permitted reserve of chalk for a cement plant at Holborough that is yet to be built. There are no longer any operational coal mines or cement works in Kent.

1.0.5 In the late 19th Century, Kent had 17 operational cement works along the Introduction Medway alone between Aylesford and Frindsbury (4) By 1966 Kent’s cement industry 1 had reduced to 7 works but the capacity was still an impressive 3.5 million tonnes per year with the Northfleet works at nearly 1.9 million tonnes per year, probably the largest production unit in Europe at the time (5). Though Lafarge has permission for a new cement works at Holborough, north of Snodland, it has recently opened (2008) an import cement terminal on the former site of Northfleet cement works. This cement terminal has the import capacity to effectively match the production capacity of the former works. It currently imports cement from a number of European cement works.

1.0.6 In 1947 there were 36 brickworks in Kent producing bricks from Brickearth in the north of the county and from the Gault Clay and Weald Clay in the centre and south of the county. In addition there were 16 registered tile works though some were tied to the aformentioned brickworks(6). There is currently 1 brickworks still operating in Kent utilising brickearth, another that has used brickearth is currently on a care and maintenance programme, whilst the brickworks based on the former Tilmanstone colliery site has closed and is for sale. The latter used colliery spoil mixed with either Weald or Gault Clay depending upon the brick style it wished to manufacture. Another former operator has closed its Kent works and has transferred manufacture of its ‘London stock’ brick to another brickworks in East Sussex to where it intends to transport its remaining Kent brickearth reserve.

1.0.7 Although there is currently no commercial interest in mining the coal deposits of Kent, there remains interest in investigating the potential oil and gas deposits of Kent, including coal bed methane extraction from the coal seams. Applications for permission to undertake geophysical and borehole exploration continue to be made.

4 http://www.medwaypilots.co.uk/page2.htm 5 C. Clear, Dr. Forty Years of UK Cement Manufacture - 1966 to 2006 (July 2006) Concrete 6 Directory of Quarries, Clayworks, Sand & Gravel Pits, etc. 11th Edition 1948 TRM3 Other Minerals Kent County Council 3 2

2 Other Minerals Minerals Other

2.0.1 The range of minerals found in Kent that fall within the umbrella of this report are illustrated in the following tree diagram. The diagram also illustrates the major uses to which these minerals are put. 4 Kent County Council TRM3 Other Minerals Other Minerals 2 TRM3 Other Minerals Kent County Council 5 3

3 Clay Clay

3.0.1 There are four principle clay horizons in Kent

London Clay. Gault Clay. Weald Clay. Wadhurst Clay.

DA ME ! GR TH D SW D " ! ! CA SE TM MA D DO " ! " " " "" AS TW

Existing Clay Permissions and Brickworks

3.0.2 In addition brickearth will be considered within this section of the report where it is dealt with in relation to its brickmaking qualities.

3.0.3 In the past all these deposits have been used to produce bricks. London Clay is considered a good engineering clay but its use as a brick clay has declined to nothing in Kent as its mineralogy makes it a difficult medium to use for this purpose. Similarly Gault Clay has declined in value for brickmaking for similar reasons though in some parts of the outcrop it does have properties that make it useful for producing bricks of a yellow colour.

3.0.4 Weald Clay still supports a large brickmaking industry in the Wealden district (which covers parts of Kent, Surrey, East and West Sussex). 6 Kent County Council TRM3 Other Minerals

3.0.5 Wadhurst Clay was historically worked for iron but is also recorded as a suitable brickmaking clay with references to brickworks in several of the local Clay geological memoirs(7)(8). The geology of the Weald with its heavily faulted centre(9) 3 possibly discouraged its use in modern brickmaking due to the limited size of individual outcrops of the clay. However, where it has been used for brickmaking the heavy iron content of the clay has produced a distinctive Sussex red hue to the bricks.

3.0.6 In addition to the brick industry, tiles and ceramic pipes including terracotta products may be made from clay of suitable quality.

3.0.7 London Clay has been extensively used as an engineering clay particularly for sea defence works around the North Kent Marshes.

3.1 National Policy

3.1.1 National Policy

MPS1: Planning for Minerals(10)

3.1.2 National policy in relation to Clay is set out in Communities and Local Government (November 2006) Minerals Policy Statement 1: Planning and Minerals Annex 2. Brick Clay (paras 2.1- 3.4):

i. To maintain and enhance the diversity of brick clay produced by making appropriate provision for supply; ii. To provide and make available brick clays at a level that reflects the high initial investment in, and high levels of capital expenditure required to maintain and improve, new and existing brick making plant and equipment. This will normally be sufficient to provide for 25 years of production at each manufacturing plant; iii. To safeguard and where necessary stockpile supplies of clay; iv. To have regard to the need for clay supply for local use and repair of heritage buildings (in Kent brickearth is used to make "stockbricks", a distinctive and specialist product. Kentish stockbricks are used extensively for conservation work, particularly in London); and v. To extract clay as close as practicable to the brickworks that it is supplied to.

7 E. R. Shepherd-Thon et al (1966) Geology of the Country around Tenterden 8 C.R. Bristow and R.A.Bazley (1972) Geology of the Country around Royal Tunbridge Wells. Geological Survey of Great Britain 9 C.R. Bristow and R.A.Bazley (1972) Geology of the Country around Royal Tunbridge Wells. Geological Survey of Great Britain 10 Communities and Local Goverment (2006) Minerals Policy Statement 1 : Planning and Minerals Annex 2 Brick Clay (paras 2.1 - 3.4) TRM3 Other Minerals Kent County Council 7 3 3.2 Brickearth Clay

DA ME GR

Smeed Dean Brickworks TH Quinton Road SWClaxfield Farm Hempstead House Ospringe Brickworks

CA Hammill SE TM

MA DO

AS TW

Brickearth Deposits and Planning Permissions.

3.2.1 Brickearth is a superficial deposit that overlies the Chalk and Tertiary deposits of North Kent. The deposits are wind formed loess and have a high quartz content. The deposits of brickearth also contain calcite which is the reason for the yellow hue of bricks manufactured from it. If calcite is absent or low in content the brickmakers added ground chalk readily available to maintain the yellow colour. The deposits are not very thick but cover extensive swathes of land from the Medway to the English Channel. Elsewhere in Kent there are horizons identified as Brickearth but they have not been developed for brickmaking to the same extent as the northern deposits.

3.2.2 Brickearth deposits of Kent have been worked in various areas of the county but particularly north of the chalk escarpment in the Faversham – Sittingbourne area. These deposits produce a yellow brick that was used extensively during the Victorian period in London and north Kent. Its ubiquitous use in London resulted in it becoming known as the ‘London Yellow Stock’. The high quartz content was probably the reason for its durability in the harsh weathering conditions that prevailed in Victorian and post Victorian times.

3.2.3 There are currently two brickworks in Kent, Smeed Dean (Wienberger) in Sittingbourne, which is still operating, and Ospringe (W. T. Lamb) in Faversham which is under a care and maintenance programme. This follows the closure of Funton (Ibstock Brick) between Lower Halstow and Iwade and Hammill (Hammill Brick Ltd.) near Eastry. Ibstock Brick the owners of Funton have transferred their 8 Kent County Council TRM3 Other Minerals

production to their Ashdown brickworks near Bexhill in East Sussex, where they claim to be able to utilise the brickearth from their permitted reserves in Kent to Clay continue manufacturing the London stock brick. 3 3.2.4 It would appear from discussions with industry that the ongoing recession and corresponding downturn in the construction industry will continue to adversely affect brick production, for example the Smeed Dean works have had enforced shutdowns in an effort to reduce their stocks of bricks.

3.2.5 The two remaining brickworks, Smeed Dean and Ospringe, will need further reserves of brickearth to be permitted if production is to be maintained into the future. Ibstock Brick will also need further reserves if they wish to continue manufacturing the ‘London yellow stock’ brick in East Sussex.

3.2.6 Smeed Dean (Sittingbourne) Brickworks

1. Information supplied in 1987 in support of application SW/86/1052 at Claxfield Farm estimated the volume of brickearth available there at 222,000 m3. In 1998 the operator anticipated an annual output of 20 million “Smeed Dean” yellow London stockbricks. “At an annual production rate of 18.5 million green bricks, the brickearth available would be sufficient for 9.67 years production”. On this basis, with 800 m3 being needed to produce 1 million bricks, an output of 20 million bricks would require some 16,000 m3 of brickearth per year. 2. Current permitted reserves are at:

i. Quinton Road, Sittingbourne (SW/78/1342). These are considered to be almost exhausted; the only remaining reserves are a small landlocked area south of the Staplehurst Road link; ii. Claxfield Farm, Teynham (permission SW/86/1052, with new conditions determined by SW/04/823). A revised working and restoration scheme submitted in 2002 stated that the remaining extraction area of 11.5h had been assessed to contain 175,000 m3 of extractable brickearth. This would yield an 11 year supply, so lasting to about the end of 2012.

To secure a 25 year supply from the beginning of 2008 would mean identifying resources for a further 20 years, 360,000 m3.

A Potential Brickearth Working at Paradise Farm, Newington, believed to be under the operator’s control, could yield some 465,000 m3 of brickearth (see Table 1).

3.2.7 Ospringe Brickworks

The works, until recently, produced some 1.8 million red stockbricks per year. On the basis that about 1,500 cubic metres of brickearth is needed to produce 1 million bricks, the annual brickearth requirement for Ospringe would be about 2,700 m3. TRM3 Other Minerals Kent County Council 9 3 The permitted sites and potential brickearth workings identified at Ospringe in Clay the Kent Minerals Subject Plan Brickearth Written Statement May 1986 have been worked out. A recently permitted reserve at Ospringe, west of the Western Link Road, between the A2 and the railway (SW/94/967 and with new planning conditions determined by SW/98/251) gave only a very few years supply. That permission had estimated reserves at 5,000 m3 and they have been fully excavated. The operator has no permitted reserves of brickearth and the brickworks are on a care and maintenance programme for the foreseeable future. To secure a 25 year supply from the beginning of 2012 would mean identifying resources for a further 67,500 m3. In the Swale Borough Local Plan (Adopted February 2008) the brickworks site has been included within a proposed employment site known as the Western Link, Faversham with attached Policies B2, B14 and B15. Swale Borough Council, subject to new brickearth resources being identified, would support the continued use of the brickworks at the current location or some other suitable location appropriately located to the new raw material source.

3.2.8 In addition to the “dedicated” permitted reserves and potential additional resources identified in para 3.2.6 and 3.2.7 above, there are a number of “freestanding” “potential brickearth workings” (all are identified in Table 1). Set against current and expected useage, together they constitute a very considerable resource, and subject to operator interest account will be taken of them as part of the assessment of future brickearth requirements.

Table 1: Potential Brickearth Workings in Kent(11)

Location Estimated Reserves (all in Swale borough)

Newington Area

BE1. Libbetwell North 135,000 m3

BE2. Libbetwell South 185,000 m3

BE3. Mill Hill * 300,000 m3

BE4. Paradise Farm 465,000 m3

Bobbing Area

BE5. Bobbing Kennels/Quinton Farm 345,000 m3 House*

Teynham Area

11 Includes: those identified in the Kent Minerals Subject Plan Brickearth Written Statement May 1986 which remain unworked as at the beginning of 2011, a registered dormant site, and earlier permissions for brickearth working which have now lapsed. 10 Kent County Council TRM3 Other Minerals

BE6. West Tonge Farm * 45,000 m3

Clay BE7. Claxfield Farm 30,000 m3 3 BE8. Barrow Green(12) 205,000 m3

BE9. Barrow Green Extension(13) 120,000 m3

BE10. Hempstead House 35.000 m3

Total 1,865,000 m3

Source: Brickearth Subject Plan, Proposals Map and MPA estimates.

3.2.9 Although brickearth deposits occur south of the Chalk escarpment, they are not currently exploited though there does remain one dormant Interim Development Order permission (I.D.O.). (I.D.O's are permissions granted before July 1948 when the Town & Country Planning Act 1947 came into force).

3.3 Brick Clay

3.3.1 There is one tile works (Babylon Tile Works) that utilises brick clay in the County. The only brickworks that utilised brick clay in recent times was the Tilmanstone Colliery site which closed in 2010. At the time of writing this report the site is for sale.

12 Known to be under the control of a brick manufacturer. 13 Known to be under the control of a brick manufacturer. TRM3 Other Minerals Kent County Council 11 3 Tilmanstone Brickworks Clay

3.3.2 Tilmanstone brickworks was a modern facility that was built at the former Tilmanstone Colliery pit head. It utilised the on-site colliery shale as one of its ingredients blended with Weald Clay from Pluckley or Gault Clay from Aylesford dependent on the colour of brick it wished to produce. However it has suffered from the recent recession and the plant has closed and been put up for sale. As in the case of the brickearth deposits, this facility transported its Weald clay over 40 kilometres to the factory and Gault Clay over 60 kilometres. Substantial reserves of Weald clay remain in the ground at the Pluckley site but no in situ reserves of Gault Clay, there are though some reserves of both currently stockpiled at Tilmanstone.

3.3.3 The reserves of Weald Clay at Pluckley were estimated to be in excess of 1 million m3 in January 2008, with an annual consumption projected at 20,000 m3 per annum, reserves should last beyond the plan period.

3.3.4 If the brickworks were to re-open additional Gault Clay reserves may need to be identified and allocated to enable the long term continuation of yellow brick production at Tilmanstone to compliment the red brick produced from the Weald Clay from Pluckley. 12 Kent County Council TRM3 Other Minerals

3.3.5 The tile works situated south of Maidstone utilises Weald Clay. This is a small ‘cottage‘ industry that manufactures traditional hand made Kent peg tiles. The current Clay planning permission requires extraction to cease by April 2022 and for Kent Peg tile 3 manufacturing to cease after a further year. Permitted reserves are sufficient to supply the tile works beyond 2022. The operator has expressed an interest in the tile works continuing in production beyond 2022.

Kiln at Babylon Tile Works

3.3.6 Substantial permitted reserves of brick clay remain in 4 dormant sites associated with former brickworks that are now closed. These sites are situated at Naccolt, near Wye, Chiddingstone, Frittenden and Staplehurst (I - Gault Clay and 3 - Weald Clay), though doubt exists as to whether any of these sites will be worked again.

Table 2 : CLAY FOR BRICK, TILE, ETC. (Tonnes sold in Kent)

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

91,000 124,000 **** 103,000 85,000 -*

Source - National Statistics, Business Monitor PA1007, Table 8. (Note: the National Statistics Business Monitor does not identify Medway in its list of Authorities for South East England, it is therefore possible that the figures in the table include some production from Medway, although this is unlikely as there are no operational brickworks in Medway) TRM3 Other Minerals Kent County Council 13 3 * withheld to avoid disclosure Clay

- nil or less than 500 tonnes

3.3.7 Other Sources of Clay

3.3.8 In addition to the permitted reserves for the works identified in paras 3.2.1 to 3.2.5 above and in chapter 4 below as a cement making material, Kent has a number of “freestanding” clay working permissions (Table 3). Set against current and expected useage, together they constitute a very considerable resource, and account will need to be taken of them as part of any assessments of future clay requirements.

Table 1

Table 3

TABLE 3 OTHER PERMITTED CLAY RESERVES IN KENT ¹

Quarry Geology Permitted Reserves at 1/1/2011 (cubic metres)

North Kent

CL1. Norwood London Clay 100,000 (Swale) (Engineering)

East Kent

CL2. Naccolt Gault Clay 1,790,000 ² Brickworks (Ashford)

CL4. London Clay 1,000,000 Winterbourne (Engineering) (Swale)

Mid and South West Kent

CL5. Weald Clay 270,000 ² Chiddingstone (Sevenoaks)

CL6. Frittenden Weald Clay 650,000 ² (Tunbridge Wells)

CL7. Greatness Gault Clay Clay at this site is required for the (Sevenoaks) engineering of the landfill on its completion. 14 Kent County Council TRM3 Other Minerals

CL8. Staplehurst Weald Clay 200,000

Clay (Maidstone) 3

TOTAL 4,010,000

Source – Planning application files and Kent Minerals Local Plan Chalk & Clay 1997..

¹ Excluding those reserves “tied” to, or currently supplying, specific brick and tile works (see paras 3.3.2 and 3.3.3). Accordingly, a minimum of some 1 million cu metres is potentially available at Pluckley, Ashford . There is also potentially a further 2 million tonnes available at Park Farm Wrotham, Tonbridge and Malling ), a cement clay permission relating to the former Halling Cement works in Medway Authority area. This cement works has permanently closed and the site is being redeveloped for other uses.

² MPA estimate, as set out in the adopted Minerals Local Plan (table 9.1 on page 40). No recent working has taken place.

3.4 Engineering Clay

3.4.1 Engineering Clay is that material used for construction purposes mainly as bulk fill, waterproof capping material or sea/river flood defence work. Historically London Clay has been used in the north as protection against tidal flooding in the river estuaries. Supplies have tended to come from borrow pits close to the area in greatest need of protection but Norwood Quarry (Waste Recycling Group) on the Isle of Sheppey has proved a useful long term reserve that has served landfill restoration and sea defence work as well as providing the bulk fill on the approach to the new Swale Bridge. Reserves at this site for sale off-site are near exhaustion (See Table 3).

3.4.2 Shelford Quarry and Landfill (Brett/Viridor) site has also supplied London Clay as an engineering clay but permitted reserves at this site are now exhausted.

3.4.3 Potential reserves of London Clay exist at Winterbourne Quarry near Canterbury (See Table 3). However this site is poorly located to the highway network and has only been worked intermittently for its sand deposit.

3.4.4 In the past there has been no provision in terms of areas of search, supplies have been met by either applications for small borrow pits, permissions granted as extensions to existing mineral workings where clay occurs as overburden or utilising brick clay. However, the reserves of clay outlined in Table 3 Other Permitted Clay Reserves in Kent would imply there is no need to allocate any further areas of clay for engineering purposes. TRM3 Other Minerals Kent County Council 15 3 3.4.5 From the National Statistics, Business Monitor PA2007 the following table Clay illustrates the level activity of clay used for construction purposes from 2000 to 2009 inclusive:

Table 4 CLAY USED FOR CONSTRUCTION PURPOSES IN KENT. ( SALES IN TONNES)

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

* 22,000 67,000 39,000 57,000 1,000* -1,000 32,000

*withheld to avoid disclosure

- nil or less than 500 tonnes

3.4.6 The figures in Table 4 indicate an average use of approximately 27,400 tonnes per annum for the last 10 years (the * years which were withheld in the above table were not included in this calculation). If these figures were projected for the life of this plan the total clay required would be approximately 500,000 tonnes.

3.5 Specialist Uses

3.5.1 Clay is a general term for a family of minerals that have a variety of forms and composition. The variety of forms has meant that clay minerals may be used for many industrial purposes.

3.5.2 Clay has been divided by mineralogists into 4 groups (14):

Kaolinite Group - with varieties such as kaolinite, nacrite, dickite Montmorillinite/smectite group - with varieties such as pyrophyllite, bentonite talc, vermiculite, sauconite, saponite, nontronitemontmorillinite, Illite Group - with varieties such as illite. Chlorite Group (not always regarded by some as a clay group and has no industrial use).

3.5.3 The kaolinite group of minerals are widely used in ceramics, as a filler for paint, rubber and plastics and the largest use is in the paper industry that uses kaolinite to produce a glossy paper such as is used in most magazines.

14 see http://www.galleries.com/minerals/silicate/clays.htm 16 Kent County Council TRM3 Other Minerals

3.5.4 The montmorillinite/smectite group uses are many and include facial powder (talc), filler for paints and rubbers, electrical, heat and acid resistant porcelain, in Clay drilling muds and as a plasticizer in moulding sands and other materials. 3 3.5.5 The illite group is a common constituent in shales and is used as a filler and in some drilling muds.

3.5.6 London clay is principally a mixture of illite/smectite, Gault clay is principally a mixture of illite/smectite, kaolinite and illite/mica, Weald clay is principally a mixture of illite and kaolinite and Wadhurst clay is kaolinite and illite. These mixtures of clay minerals make these formations useful for bulk processes but not specialist high purity. Therefore Kent clays do not have a major use for specialist industrial use.

3.5.7 However the Fullers Earth deposits around Maidstone were used in the past for their unique properties in the wool and cloth industry.

3.5.8 Fullers Earth was obtained from the Sandgate Beds in Kent. These deposits were analysed for the British Geological Survey in 1956 and found to be pure montmorillinite (15) The last operation to extract Fullers Earth was undertaken near Grove Green in Maidstone by Laporte Industries Ltd. Since the closure of the Laporte site, Fullers Earth deposits are no longer commercially exploited in Kent.

15 see B.C. Worssam (1963) Geology of the Country around Maidstone. Geological Survey of Great Britain TRM3 Other Minerals Kent County Council 17 4

4 Chalk Chalk

4.1 Cement

4.1.1 National Policy

National Policy

MPG 10: Provision of raw material for the cement industry.

4.1.1.1 National policy is set out in Minerals Planning Guidance 10: Provision of raw material for the cement industry (MPG 10)(16). The government recognises the cement industry as being of major importance to the national economy, supplying an essential product to the construction and civil engineering industries. Also, great importance is placed on reducing the level of imports of building and construction materials. To counter the rising import trend and to provide employment, domestic cement production is encouraged, and any export opportunities that may arise should not be discouraged. It is considered to be in the national interest to maintain and increase cement production, and to increase the scope for competition. An adequate and steady supply of raw materials to maintain production to meet the needs of the community is essential (MPG10, paras 2, 3 and 30).

4.1.1.2 For these reasons the Mineral Planning Authority (MPA) is expected to make provision for an adequate supply of raw materials for the cement industry. This means assessing likely raw material needs, examining supply options, identifying preferred areas of working to meet needs, and safeguarding mineral resources for future working (MPG10, paras 3 and 30).

4.1.1.3 The MPA is expected to maintain, for each cement works, a landbank of at least 15 years. Where significant new investment in plant is agreed, the landbank should provide for at least 25 years. New plant on a greenfield site should be provided with a landbank lasting more than 25 years. Sufficient land should be allocated to maintain the landbank throughout, and at the end of, the plan period (MPG10, paras 57-59).

4.1.1.4 Most of the region’s cement requirements are now imported. For this reason suitable wharves and rail distribution sites should be protected from inappropriate development, which may constrain their future use.

4.1.2 Cement

4.1.2.1 In Kent the cement industry established itself on the banks of the Thames and Medway estuaries utilising the local resources of chalk and clay (17)

16 Departmentfor Communities and Local Government (1991) Minerals Planning Guidance 10: Provision of raw material for the cement industry 17 See .http://www.cementindustry.co.uk/the_industry/profile.aspx 18 Kent County Council TRM3 Other Minerals

4.1.2.2 The Chalk Marl (Lower Chalk) is the basal layer and is rich in clay minerals as well as calcium carbonate whereas the Middle and Upper Chalk are very pure

Chalk forms of calcium carbonate with the occurrence of layers/seams of flint as discrete

4 nodules. Clay for blending with the Middle and Upper Chalk is principally sourced from either the Gault Clay or the London Clay though the original pioneers also used clay from the estuarine mud banks.

4.1.2.3 The chalk marl is a very consistent mix of calcium carbonate and clay and is the prevalent mineral source of the Medway valley. However, within the main North Downs scarp face the Middle Chalk becomes more significant and as this is a much purer source rock for cement production it requires blending with one of the local clays. In the Medway valley this has tended to be Gault Clay e.g. Paddlesworth Clay Pits near Snodland.

4.1.2.4 On the Thames estuary the Upper and Middle Chalk form the principle calcium carbonate source which requires the addition of clay to create cement through the high temperature calcining process. In recent times London Clay has been used to provide the argillaceous element to mix with the chalk to create the cement.

4.1.2.5 At present there are no productive cement works in Kent, despite there being a planning permission (TM/98/785) for a major new plant near Snodland granted on 26th November 2001. The sustainability of relying on long distance imports for supplying the south east with cement is an issue, though this would be resolved with the construction of the new cement works.

4.1.2.6 If constructed, this cement works would have an approximate life of 35 years producing 1.4 million tonnes per annum (m.t.p.a.) utilising 72 million tonnes of raw material.

4.1.2.7 Lafarge Cement Ltd have replaced their former cement works at Northfleet with a cement import facility based on its Thamesside location (Northfleet Works, The Shore, Northfleet, Gravesend), permission GR/05/561. The facility has a capability of importing 1 million tonnes /annum. The cement is currently distributed by road but a rail connection has been permitted as part of an aggregate importation terminal (GR/09/286) and this has been further reinforced by the recent permission (GR/10/1127) for the cross-rail temporary tunnelling logistics facility on the same former cement works site. Construction of this rail connection for the aggregate wharf and the temporary cross rail facility could be utilised by for cement export in the future.

4.2 Agricultural Lime

4.2.1 The only significant mineral excavated regularly in Kent for agricultural use is chalk. It is used primarily for applying to soils in a crushed/ground form. In 1997 the Kent Minerals Local Plan Chalk and Clay/Oil and Gas assessed future demand for agricultural chalk on the basis of an average useage of some 80,000 tonnes per TRM3 Other Minerals Kent County Council 19 4 year (tpa). At that time it was concluded that, unless large areas of land were to be Chalk permanently removed from agricultural production by set aside or other means, current consumption of agricultural lime was unlikely to alter significantly.

4.2.2 However since then, sales of chalk for agricultural use have been at a much lower level. Table 5 shows sales since 2000 as running at an average of about 43,000 tpa. In 2006 a significant increase in sales over previous years was recorded, however this figure appears to be an abnormal year as the two subsequent years have returned to the 40,000 tpa. If sales were maintained at the 2006 level over the 18 year period 2012-2030, then provision would need to be made for nearly 1,135,000 tonnes of chalk for agricultural use, but using the average of the last 10 years it would need a reserve of 772,200 tonnes.

Table 5

TABLE 5 CHALK – KENT EXTRACTORS’ SALES FOR AGRICULTURAL USE

Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Sales 33,000 ** 48,000 39,000 37,000 63,000 39,000 42,000 47,000

Source – National Statistics, Business Monitor PA 1007, Table 9

Withheld to avoid disclosure.

4.2.3 In Kent, the quarries identified in Table 6 supply, or have supplied, chalk for agricultural use. The estimates of permitted reserves are derived from information about production and reserves given in planning applications and more recently discussions with the relative operators, as detailed in Appendix 1, Table 8.

Table 6

TABLE 6 KENT - PERMITTED CHALK RESERVES THAT ARE, OR COULD BE, SOLD FOR AGRICULTURAL USES. (tonnes)

Quarry Estimated Permitted Reserves at 1/1/2011

North Kent

CH1. Darenth Road Quarry (Dartford) 200,000

CH2. Pinden Quarry (Dartford) 1,280,000

Mid and South West Kent

CH3. Detling Quarry (Maidstone) 260,000

East Kent 20 Kent County Council TRM3 Other Minerals

CH4. Beacon Hill Quarry (Ashford) 240,000

Chalk CH5. Brabourne (Canterbury) Not known 4 CH7. Crundale Quarry (Ashford) 227,000

CH8. Hegdale Quarry (Ashford) 149,000

CH9. Rowling Quarry (Dover) 66,000

Total Permitted Reserves 2,422,000

Source – planning application files and consultation with the producing companies

4.2.4 Permitted chalk reserves, of more than 2.422 million tonnes at a conservative estimate, are far in excess of anticipated requirements for agricultural chalk during the plan period to 2030. Taking account of the likely modest future requirements for specific parts of Kent, there is also considered to be a reasonable “spread” of permitted reserves across the county as a whole.

4.3 High Purity

4.3.1 The Kent Minerals Local Plan Chalk and Clay/Oil and Gas Adopted December 1997 noted that manufacturing industry will continue to have a need for calcium carbonate (chalk) for a wide range of products. In 2007 the British Calcium Carbonates Federation estimated that for the period up to 2021, demand for calcium carbonate in markets like paper and other industrial markets is expected to increase by about 5% per year.

4.3.2 The statistics identify only a very small amount of chalk as having been sold for construction uses. normally 2,000 -3,000 tonnes per year up to 2004, however since 2005 the pattern of use has changed significantly with figures in the region of 90,000 tonnes per annum being recorded in 3 of the 4 years following 2004. Significantly in the most recent figures produced by the Natonal Statisitics Business Monitor a figure of 349,000 tonnes was recorded though this figure was probably the result of one major road project (A2/M25 junction improvements(as reported by local suppliers in confidence). If this project is discounted from the total for 2009 then the figure would be comparable with the years 2005 -2008.

4.3.3 Utilising the the past 7 years figures from Table 7, but ignoring the sales to the A2/M25 works, the average sales for this period amount to approximately 53,000 tonnes per annum equating to a required tonnage of 954,000 tonnes for the Plan period. At these levels, the amount of reserves identified in Table 6 are considered likely to be sufficient to accommodate demands for chalk for engineering and construction uses for the plan period though some provision for further permissions for engineering chalk may be required towards the end of the plan period. These could take the form of Areas of Search. TRM3 Other Minerals Kent County Council 21 4 Table 2 Chalk

TABLE 7 CHALK – KENT EXTRACTORS’ SALES FOR ENGINEERING USES

Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009†

Sales *** 2,000 3,000 95,000 90,000 81,000 5,000 349,000

Source – National Statistics, Business Monitor, PA1007, table 9

† 2009 appears to be an abnormal year with three construction projects accounting for the large increase including the A2/M25 interchange improvement and infilling of a former chalk quarry to create a development platform.

* Withheld to avoid disclosure.

4.3.4 Today, calcium carbonate powders, precipitated products and dolomite, are among the most important and versatile materials used by industry. It is used as a filler and functional additive in an incredible variety of industrial applications ranging from adhesives & sealants, building products, glass, paints & inks, paper, plastic & rubber to animal feeds, flue-gas desulphurisation, fertilizers, food, personal care, pharmaceuticals and water treatment (18)

4.3.5 Currently 30,000 tonnes a year of chalk is produced for industrial uses in England. However, there is no recorded production in Kent at this time according to the National Statistics Business Monitor 2008, Table 9.

18 http://www.calcium-carbonate.org.uk/calcium-carbonate/caco3-applications 22 Kent County Council TRM3 Other Minerals Chalk

4 DA Darenth Road Quarry ME Pinden QGuaRrry TH SW Holborough Quarry

Detling Quarry CA SE TM Rowling Chalk Pit Hegdale Quarry MA DO Crundale Limeworks Beacon Hill Quarry

Brabourne Limeworks AS TW

Legend Chalk - Cement Chalk - Other

Existing Chalk Permissions and Geology

4.0.6 Chalk is a thick limestone deposit of Cretaceous age that is widespread over the south and east of England. It is divided geologically into three main horizons Lower Chalk (or Chalk Marl), Middle Chalk and Upper Chalk, with two subsiduary horizons the Glauconitic Marl at the base of the Chalk Marl and the Melbourn Rock at the base of the Middle Chalk.

4.0.7 The Chalk horizon in Kent is defined by the North Downs. It forms a major feature across the County from Dover in the east to Westerham in the west. It also forms the main bedrock to the Isle of Thanet.

4.0.8 Chalk is a limestone which is principally the mineral calcium carbonate.

4.0.9 The Lower Chalk or Chalk Marl is an impure limestone that contains a high proportion of argillaceous (19) and arenaceous (20) minerals. At the base of this division of the Chalk is a bed known as the Glauconitic Marl, a horizon that is up to 7 metes thick. The Lower Chalk tends to make up the rising land to the base of the main escarpment of the North Downs. This horizon is up to 76 metres thick.

4.0.10 The Middle Chalk is a massive (21) rock with little contamination being almost entirely calcium carbonate with the exception of the layers of flint nodules. It is marked at the base by the Melbourn Rock and is characterised in its upper part

19 see Appendix 2 Glossary 20 see Appendix 2 Glossary 21 see Appendix 2 Glossary TRM3 Other Minerals Kent County Council 23 4 of the formation by the presence of flint nodules. It is the Middle Chalk that forms the Chalk steepest part of the North Downs escarpment and is up to 72 metres thick. The Melbourn Rock is a very hard chalk that is often recognised in the chalk escarpment by a sharp steepening in the slope of the ground.

4.0.11 Overlying the Middle Chalk is the Upper Chalk. This division of the chalk is characterised by the development of layers of flint nodules throughout the horizon. The Upper Chalk is less massive and softer than the Middle Chalk. It is up to 106 metres in thickness.

4.0.12 The Middle and Upper Chalk are much purer forms of limestone than the Lower Chalk. 24 Kent County Council TRM3 Other Minerals

5 Silica Sand

5.0.1 This is the subject of a separate joint topic report with Surrey County Council, written by GWP and published March 2010 (22). Silica Sand 5

22 GWPConsultants (2010) A Study of Silica Sand Quality and End Uses in Surrey and Kent. TRM3 Other Minerals Kent County Council 25 6

6 Energy Minerals. Minerals. Energy

6.0.1 Energy minerals are the natural minerals found in the ground that provide us with heat and power. They generally are carbon based and include the solid fuels of peat, lignite and coal and the hydrocarbons normally present in the form of oil and natural gas.

6.0.2 The solid fuels are normally present in the form of sedimentary rocks interbedded with other sedimentary rocks. Generally these rocks have to be excavated from the ground. Whereas the oil and natural gas deposits are found in porous rocks and strata that can be extracted by boreholes rather than extraction of the rock itself (although this does not apply in the case of oil shales).

6.1 Coal

DA ME GR TH SW Chislet

CA SE TM Betteshanger

Snowdown MA DO Tilmanstone

AS TW

Legend Kent Coalfield ¯ Former Collieries 0 5 10 20 Mineral & Waste Authorities outside KCC Kilometers

East Kent Coalfield and Former Colliery Sites

6.1.1 East Kent Coalfield

6.1.1.1 The East Kent Coalfield was exploited for its coal reserves from 1912 when the first coal was raised to the surface at Snowdown Colliery. It had four main collieries at its peak, Chislet, Snowdown, Tilmanstone and Betteshanger. Chislet was the first to close in 1969, when the rail industry, its main customer, switched from steam to diesel engines. During the 1970’s, the three remaining collieries were producing circa 26 Kent County Council TRM3 Other Minerals

1,000,000 tons of coal per year mainly for the steel industry due to the high burning temperature of Kent coal. However with the contraction of the steel industry, these collieries were closed with Betteshanger being the last in 1989 (23).

6.1.1.2 The East Kent Coalfield covers an area of approximately 157,900 hectares (1578.78 km2) beneath the Kent landmass but it clearly extends to the east and south beneath the English Channel. There have been up to 36 seams of coal identified in one borehole within the centre of the concealed outcrop but these reduce in number

Energy Minerals. towards the periphery of the outcrop due to its synclinal form . Of the 36 seams

6 identified in the West Court Farm borehole 12 were at least 0.4 metres thick with one being logged at 2.36 metres thick (24).

6.1.1.3 Kent coal was bituminous(25) to semi-anthracitic(26) in nature with a high calorific value and generally low sulphur content. The coal met the specifications for coking coal for steel making and was also used in the paper-making industry of Kent, for electricity generation and general industrial use.

6.1.1.4 The depth of the coal (Tilmanstone at 3035 feet and Snowdown at 3020 feet) and the difficult geological conditions made Kent coal amongst the most expensive to mine in the United Kingdom.

6.1.1.5 The Coal Authority currently has no plan to reopen or recommence the mining of coal in Kent and it is unlikely that it will arise during the life of the Minerals & Waste Development Framework.

6.1.2 Coal Bed Methane

6.1.2.1 Coal bed methane (CBM) is natural methane trapped within the coal seams when the beds were forming from the natural degradation of the plant life at the time of deposition. CBM may be extracted from unmined coal seams or from former coal mines where methane is naturally escaping from the coal seams. Coal comes in a number of forms that reflect the degree of compression to which they have been subjected. The main forms of coal (27) are brown, bituminous and anthracite . The 3 density of bituminous coal is between(28) 1.12 and 1.3 tonnes/m whilst anthracitic coal is denser at 1.3 to 1.6 tonnes/m3 . The quantity of CBM generated will vary from coal seam to coal seam.

6.1.2.2 As reported in the previous section, the East Kent Coalfield covers an area of approximately 157,900 hectares (1578.78 km2) beneath the Kent landmass but it clearly extends to the east and south beneath the English Channel.

23 see http://doverdc.co.uk/kentcoal/intro.asp 24 J. G. O. Smart et al (1966) Geology of the Country around Canterbury and Folkestone 25 Appendix 2 Glossary 26 Appendix 2 Glossary 27 See Appendix 2 Glossary 28 Terex Reference Booklet (1978) TRM3 Other Minerals Kent County Council 27 6 6.1.2.3 Current thinking (29) suggests coal seams need to be at least 0.4 metres nryMinerals. Energy thick to be economic to be developed for coal bed methane. The West Court Farm borehole identified 12 seams that met this criteria.

6.1.2.4 It is possible to achieve levels of methane production up to 12.9 m3 from one tonne of coal therefore 1 hectare of a coal seam 0.5 metres thick could yield between 6,500 and 8,000 tonnes of coal equivalent to 83,850 to 103,200 m3 of methane gas depending upon the grade of coal being exploited.

6.1.2.5 To extract coal bed methane a series of boreholes need to be drilled, normally to a pattern defined by exploratory drilling and testing of the coal seams. Current understanding of the dynamics of coal seams in Scotland suggests that one well site every square kilometre should be sufficient to ensure efficient production from the resource. However the production qualities of coal seams will vary and may require a borehole site every 1/2 km.

6.1.2.6 It is evident that subject to proving the techniques of coal bed methane extraction the potential for obtaining substantial quantities of the gas from the East Kent coalfield is enormous. In the USA, coal bed methane currently accounts for 10% of the country's natural gas production.

6.1.2.7 There is also potential for coal bed methane to be extracted from former operational coal mines, which have been closed or abandoned. These mines release methane gas as a result of the mining process and this continues even after a mine has ceased production.

6.1.2.8 In April 2011, Kent County Council received a planning application to drill an exploratory borehole to test the in situ coals, Lower Limestone Shales and associated strata. The proposed Policy CSM7 Oil, Gas and Coal Bed Methane outlined in the Minerals and Waste Core Strategy Strategy and Policy Directions Consultation would cover applications of this nature (page 70). The application is yet to be determined at the time of writing this report,

6.2 Oil

6.2.1 Kent is part of the Southern Permian Basin Area (SPBA), an area established with the discovery of the Groningen gas field in the North Sea. It is an area of oil and gas exploration and development that stretches across northern Europe from Dorset to Yorkshire in the west across Northern France, Belgium, Holland, Denmark, Germany and Poland. Ongoing exploration has established a series of oil and gas fields across this region (30). Notable commercial discoveries in the English sector of this basin associated with the Weald and south coast are Wytch Farm, Dorset (the largest onshore oil field in Western Europe), Alvington, Hampshire, Storrington, West

29 http://www.composite-energy.co.uk/drilling-cbm.html 30 see Petroleum Geological Atlas of the Southern Permian Basin Area British Geological Survey, Geological Survey of Belgium et.al. (eage.org) 28 Kent County Council TRM3 Other Minerals

Sussex and Palmers Wood Surrey. Three prospects in Kent in licence PEDL153 are in preparation for exploration drilling following geophysical evidence that exhibits the same potential regime as Palmers Wood.

6.2.2 The 1997 Kent Minerals Local Plan Chalk and Clay /Oil and Gas (31)detailed the process and procedure for licensing, prospecting and developing economic oil and gas deposits. Oil and gas licences are controlled by the Government, which has the Crown energy rights and issues the licences to oil and gas companies who wish

Energy Minerals. to purchase them. On 7th November 2007, the Secretary of State for the Department

6 of Business, Enterprise and Regulatory Reform invited applications for Licences in the 13th Landward Licensing Round, the most recent release of areas for investigation. The plan below illustrates the areas of Kent that are currently licenced.

TQ48 TQ58 TQ68 TQ78 TQ88 TQ98 TR08

TQ47 TQ57 TQ67 TQ77 TQ87 DA TQ97 ME TR07 TR27 TR37 TR47 GR PEDL245 ALAMO PEDL245 ALAMO TH TR46 TQ46 TQ56 TQ66 TQ76 TQ86 TQ96 TR06 TR16 TR26 TR36 SW

PEDL153 NP WEALD CA PEDL153 NP WEALD PEDL153 NP WEALD PEDL250 COASTAL PEDL252 COASTAL TQ45 SE TM TQ75 TQ85 TQ95 TR05 TR15 TR25 TR35 TQ55 TQ65 PEDL182 STAR MA TR DO

PEDL247 WEALD PEDL248 MIDMAR TQ PEDL249 COASTAL PEDL251 COASTAL TQ44 BidborouTgQh54 TQ64 TQ74 TQ84 TQ94 TR04 TR14 TR24 TR34 & EXL 189 TAN &Cowden AS PEDL144 EGTDOWN TR23 TR33 PEDL247 WEALD TQ43 TQ53 TQ63 TQ73 TQ83 TQ93 TR03 TR13 SH 0 5 10 20 TR12 Kilometers

TQ42 TQ52 TQ62 TQ72 TQ82 TQ92 TR02 Legend & Borehole Mineral & Waste Authorities outside KCC major urban areas TR01 ¯ TQ91 TQ41 TQ51 TQ61 TQ71 TQ81 Note : Coloured Filled Squares Represent

Location of Oil and Gas Exploration Areas in Kent

6.2.3 Kent County Council has a regulatory role in the granting of planning permission to drill the exploration boreholes and in subsequent appraisal and production development.

6.2.4 One potential oil field at Bidborough has recently been granted planning permission (TW/10/33) for further exploratory drilling and for subsequent oil and gas field testing. Previous drilling indicated the presence of hydrocarbons, which may prove suitable for extraction.

31 Kent Minerals Local Plan Chalk and Clay/Oil and Gas (1997( TRM3 Other Minerals Kent County Council 29 6 6.2.5 An exploratory borehole was also drilled at Cowden near Tunbridge Wells nryMinerals. Energy (SE/98/234). Recent correspondence between the current owners of the oil licence Cuadrilla Resources Ltd and Kent County Council indicate that the Company wish to revisit the site to undertake tests on the capped well at Cowden to establish the extent and production capability of the field. Drilling has also taken place near Lingfield in Surrey where similar indications of potentially economic oil and gas reserves within two distinct geological horizons have been found that may be contiguous with the Cowden discovery. Another small oil field in Surrey close to the border with Kent is near Oxted and is operated by Star Energy

6.2.6 Oil exploration is undertaken in two different forms geophysical exploration that can include the use of explosive charges and drilling programmes that may involve 24 hour working .

6.3 Natural Gas

6.3.1 Minor reserves have been exploited in the past (1885 and 1896) near Heathfield (32) but only two resources have been found or announced in the exploration undertaken as a result of the government licences to date, Durlstan Head in Dorset and Godley Bridge in Surrey.

32 British Geological Survey (1965) British Regional Geology Thee Wealden District 4th Edition 30 Kent County Council TRM3 Other Minerals

7 Natural Building and Roofing Stone

7.1 Policy

7.1 National Policy

MPS1: Planning and Minerals(33)

7.1.1 Minerals Policy Statements set out the Government,s national planning policies for minerals planning in England.

7.1.2 MPS 1 specifically refers to the need to provide specialist building materials in Paragraph 15 Supply. In bullet point 8 it states ”recognise the important role that small quarries can play in providing historically authentic building materials in the conservation and repair of historic and cultural buildings and structures.”

7.1.3 This statement is supported by a complete Annex to MPS 1 (Annex 3) pertaining to natural stone and roofing stone. Natural Building and Roofing Stone

7 7.1.4 Planning Policy Guidance Planning and the Historic Environment (PPG15) deals mainly with the protection of the historic built environment but Annex C and in particularly the sections on External Elevations and Roofs where the text states that Planning Authorities should provide for the preservation of the fabric of the building with materials comparable to those used originally.

7.1.5 The proposed Policy CSM6 Building Stone outlined in the Minerals and Waste Core Strategy Strategy and Policy Directions Consultation (page 70) would assist in meeting the County's need to provide natural stone building materials to restore the fabric of its historic buildings. Option 8 of the same document also provides for the safeguarding of the potential building stone sources into the future affording our built heritage protection into the future.

33 Communities and Local Government (2006) Minerals Policy Statement 1: Planning and Minerals. TRM3 Other Minerals Kent County Council 31 7 Natural Building Stone Outcrops in Kent. aua uligadRoigStone Roofing and Building Natural

Local Building Stone Horizons Hythe Beds Large 'Paludina' Limestone Small 'Paludina' Limestone 'Cyrene' Limestone Upper Tunbridge Wells Sand 0 5 10 20 30 Cuckfield Stone Kilometers Ardingley Sandstone ± Lower Tunbridge Wells Sand (C) Crown Copyright. All rights reserved 100019238, 2010 Tunbridge Wells Sand

7.1.6 Kent, like many areas of Britain, has a distinct built environment that has utilised the materials available to the local craftsmen. Stone buildings constructed of ragstone, sandstone, flint and limestone have all contributed to local distinctiveness corresponding to the indigenous stone(34).

7.1.7 Current provision of natural stone for conservation and new build is limited to two ragstone quarries in Kent, Blaise Farm Quarry and Hermitage Quarry. Many of the former sources of Ragstone for example Spot Lane Quarry and Boughton Quarry have been redeveloped for housing or restored by landfill.

7.1.8 Other sites such as Mote Park in Maidstone are now significant recreational or protected areas where even modest extraction of specialist stone would be unlikely to be acceptable on environmental grounds. Former quarries that have regenerated naturally following cessation of quarrying often develop into areas rich in ecological interest.

34 Appendix 2 Glossary 32 Kent County Council TRM3 Other Minerals

7.1.9 Ragstone is Kent's best known building stone (35). It has had a long history of use. Importantly, its use has not been confined to Kent but has been exported to London and Essex, where it has been used in a number of iconic buildings (e.g. Tower of London). Hence it will be important to ensure its provision and protection into the future.

7.1.10 In the case of Ragstone, there are two large quarries currently permitted for the production of construction aggregates,whose operators are willing to provide selected stones for masonry and building purposes. However the Ragstone beds are not uniform in composition nor structure and research needs to be undertaken to enable matching of stone for that being replaced in buildings by that currently extracted. Research in other natural building stones has shown that if the stone is not equally matched it can exacerbate weathering of the building fabric.

7.1.11 In addition to Ragstone, Tunbridge Wells Sandstone, Bethersden Marble and flint from the Chalk have been popular building materials and supplies will be needed into the future to maintain those buildings constructed in these materials.

Natural Building and Roofing Stone Calcareous tufa, found in small outcrops near Ditton, has been used in a few buildings,

7 notably Leeds Castle. These materials do not have a traditional use as construction aggregates, therefore it is unlikely that these materials (excluding flint which in recent years has been a by-product of the cement and agricultural lime industries) will warrant operations on the scale of a sand and gravel pit or a hard rock quarry development.

35 see John Newman. West Kent and the Weald. The “Buildings of England” Series, First Edition, Sir Nikolaus Pevsner and Judy Nairn, eds. (London: Penguin, 1969), TRM3 Other Minerals Kent County Council 33 7 Ragstone Retaining Wall at Springfield roundabout Maidstone. aua uligadRoigStone Roofing and Building Natural 34 Kent County Council TRM3 Other Minerals

8 References

1. C.R. Bristow and R.A.Bazley (1972) Geology of the Country around Royal Tunbridge Wells. Geological Survey of Great Britain 2. British Regional Geology The Wealden District Fourth Edition (1965) British

References Geological Survey. 8 3. H.G. Dines et al (1969) Geology of the Country around Sevenoaks and Tonbridge Geological Survey of Great Britain 4. Directory of Quarries, Clayworks, Sand & Gravel Pits, etc. 11th Edition 1948. 5. C. Clear, Dr. Forty Years of UK Cement Manufacture - 1966 to 2006 (July 2006) Concrete 6. Communities and Local Government (November 2006) Minerals Policy Statement 1: Planning and Minerals Annex 2. Brick Clay 7. Communities and Local Government (November 2006) Minerals Policy Statement 1: Planning and Minerals Annex 4. On-shore oil and gas and underground storage of natural gas. 8. Kent Minerals Subject Plan Brickearth Written Statement (Adopted May 1986). Kent County Council 9. Kent Minerals Local Plan Chalk and Clay/Oil and Gas (Adopted December 1997). Kent County Council 10. John Newman. West Kent and the Weald. The “Buildings of England” Series, First Edition, Sir Nikolaus Pevsner and Judy Nairn, eds. (London: Penguin, 1969), 11. E.R. Shepherd-Thorn (1988) Geology of the Country around Ramsgate and Dover. Geological Survey of Great Britain 12. J.G.O. Smart et.al (1966) Geology of the Country around Canterbury and Folkestone. Geological Survey of Great Britain 13. B.C. Worssam (1963) Geology of the Country around Maidstone. Geological Survey of Great Britain 14. http://www.calcium-carbonate.org.uk/ 15. http://www.cementindustry.co.uk/the_industry/profile.asp 16. https://www.og.decc.gov.uk/ 17. http://doverdc.co.uk/kentcoal/intro.aspx 18. http://www.composite-energy.co.uk/about-cbm.html Source of data on coal bed methane. 19. http://www.medwaypilots.co.uk/page2.Htm 20. http://www.galleries.com/minerals/silicate/clays.htm 21. Petroleum Geological Atlas of the Southern Permian Basin Area British Geological Survey, Geological Survey of Belgium et.al. (eage.org) TRM3 Other Minerals Kent County Council 1 pedx1 Appendix Appendix 1

Table 3 Chalk Planning Permissions

Planning Quarry Decision Date Permission

North Kent

DA/98/330/MR29 Darenth Road Quarry Dartford 26.10.1999 (Dartford)

DA/07/1 Pinden Quarry Longfield (Dartford) 27.03.2008

Mid and South West Kent

MA/04/335/MR42 Detling Quarry Detling (Maidstone) 09.02.2005

East Kent

AS/97/360/MR13 Beacon Hill Quarry Charing 25.02.1998 (Ashford)

WE/6/61/185 Brabourne Limeworks (Ashford) 04/12/1961

AS/01/677/MR7 Crundale Quarry Nr Wye (Ashford) 13/11/2001

AS/94/1155 Hegdale Quarry Challock (Ashford) 28/03/1995

DO/07/179/MR35 Rowling Quarry Woodnesborough 12/07/2007 (Dover) 2 Kent County Council TRM3 Other Minerals

Appendix 2

Glossary

A Appendix 2 Anthracite, a hard natural coal that burns slowly and gives intense heat, the -itic carbon content is between 92.1% and 98%

Arenaceous Resembling, derived from, or containing sand

Argillaceous Containing, made of, or resembling clay; clayey.

bedrock solid unweathered rock lying beneath surface deposits of soil and superficial deposits

Bituminous soft black coal, rich in volatile hydrocarbons, that burns with a smoky coal yellow flame. Fixed carbon content: 46-86 per cent

brickearth clay or earth suitable for, or used in making, bricks.

Brown coal a low-quality coal intermediate in grade between peat and bituminous coal (see lignite)

Chalk a soft, white, porous sedimentary rock, a form of limestone composed of over 95% of the mineral calcite. Calcite is calcium

carbonate or CaCO3

Chalk marl See Marl: in this instance a clayey limestone. Also refers to the lowest division of the chalk (Lower Chalk)

Chloritic Marl The lowest bed of the chalk marl characterised by containing the green minerals chlorite and glauconite.

Cretaceous The last period of the Mesozoic era, between the Jurassic and Tertiary periods, lasting 80 million years during which chalk deposits were formed and flowering plants first appeared.

D TRM3 Other Minerals Kent County Council 3 pedx2 Appendix Drift In the UK the term drift is commonly used to describe any deposits of quaternary age. (Geology)

Economic Is a rock or mineral that has a commercial value. mineral

Flint a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.[

Indigenous Indigenous resources, resources which exist within local geography, that are not imported

Interim With the ending of the war, the Government came to the conclusion Development that it was important to establish a balance between the Country's Order (IDO) need for minerals in the post-war reconstruction period and the need to avoid conflict with other land uses and the protection of amenity. The Town and

Country Planning (General Interim Development) Order 1946 therefore withdrew previous permitted development rights for surface mineral working. Thus, from October 1946, most new surface mineral working needed an express grant of permission from the interim development

authority. Quarrying undertakings which had not already secured interim development permission were encouraged to apply for such permission. 4 Kent County Council TRM3 Other Minerals

Jurassic Interval of geologic time, 199.6–145.5 million years ago, that is one of the three major divisions of the Mesozoic Era, preceded by the Triassic Period and followed by the Cretaceous Period. Appendix 2

Lignite a brown carbonaceous sedimentary rock with woody texture that consists of accumulated layers of partially decomposed vegetation: used as a fuel. Fixed carbon content: 46-60 per cent; calorific value: 1.28 107 to 1.93 107 J/kg (5500 to 8300 Btu/lb) Also called brown coal

Marble Is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. It is commonly used for sculpture and as a building material. The term can also be applied to sedimentary calcareous rocks that can take a polish.

Marl A clayey sediment rich in lime, including every gradation between calcareous clay and clayey limestone.

Massive Without internal structure or layers and homogeneous in composition.

Mineral is a naturally occurring solid chemical substance that is formed through geological processes and that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties.

Mineralogist studies rocks, gems and other minerals.

Mineralogy is the study of the chemistry, crystal structure, and physical (including optical) properties of minerals.

N TRM3 Other Minerals Kent County Council 5 pedx2 Appendix O

Quarry Is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, construction aggregate, riprap, sand, and gravel

Quaternary The geological period of the Cenozoic Era immediately following the Tertiary. It is subdivided into the Pleistocene and the Holocene Epochs. It began about 1,640,000 years ago.

Reserve are valuable and legally and economically and technically feasible to extract.

Resource are potentially valuable, and for which reasonable prospects exist for eventual economic extraction.

Solid geology Is defined by the British Geological Survey as the mappable rocks laid out in a stratigraphical column in sequential order with the youngest rock at the top and the oldest rock at the bottom. (see superficial deposits)

Stock brick a brick, hand made, using a stock mould. Later came to mean a large number (stock) of bricks all manufactured in the one locality, i e London stock brick

Superficial In the British Geological Survey superficial deposits refer to all deposits geological deposits of Quaternary age. All pre-quaternary deposits are referred to as bedrock or solid geology. Superficial Deposits were previously called drift.

Syncline, A syncline is a downward fold of stratified rock in which the strata synclinal slope towards a vertical axis 6 Kent County Council TRM3 Other Minerals

Tertiary Of or belonging to the geologic time, system of rocks, or

Appendix 2 sedimentary deposits of the first period of the Cenozoic Era, characterized by the appearance of modern flora and of apes and other large mammals

Town & The Town and Country Planning Act 1947 was an Act of Parliament Country in the United Kingdom passed by the post-war Labour government. Planning Act It came into effect on 1 July 1948, and along with the Town and 1947 Country Planning (Scotland) Act 1947 was the foundation of modern town and country planning in the United Kingdom.

Tufa A variety of limestone, formed by the precipitation of carbonate minerals from ambient temperature water bodies.

Weald is the name given to a physiographic area in South East England situated between the parallel chalk escarpments of the North and the South Downs. It should be regarded as three separate parts: the sandstone "High Weald" in the centre; the clay "Low Weald" periphery; and the Greensand Ridge which stretches around the north and west of the Weald

Wealden Embraces the major part of Kent, the whole of Sussex, the southern District half of Surrey and a small part of Hampshire.

XYZ