Other Minerals

Kent Minerals and Waste Development Framework

Planning for the future of minerals and waste in Kent

Evidence Base for the Minerals Sites Development Plan Document Preferred Options consultation

Minerals Topic Report 3: Other Minerals

May 2012

TRM 3: Other Minerals (2012) Kent County Council Contents 1 Introduction 1

2 Other Minerals 3

3 Clay 4 3.1 Introduction and History of Clay Working in Kent 4 3.2 Brickearth 5 3.3 Brick Clay 10 3.4 Engineering Clay 14 3.5 Specialist Uses 15

4 Chalk 17 4.1 Chalk Geology 17 4.2 Cement 18 4.3 Agricultural Lime 19 4.4 High Purity and Engineering Chalk 21

5 Silica Sand 23

6 Energy Minerals 24 6.1 Introduction 24 6.2 Coal Deposits in Kent 24 6.2.1 East Kent Coalfield 24 6.2.2 Coal Bed Methane 26 6.2.3 Underground Coal Gasification 27 6.3 Oil 28 6.4 Natural Gas 30

7 Natural Building and Roofing Stone 31

8 References 35

Appendices

Appendix 1: Planning Permissions 37

Appendix 2: Glossary 39 Kent County Council TRM 3: Other Minerals (2012) Contents TRM 3: Other Minerals (2012) 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 TRM 3: Other Minerals (2012)

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, north of Snodland 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 seven 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 potential to match the production capacity of the former works. It currently imports cement from a number of European cement works through No. 42 Wharf at Northfleet.

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 aforementioned brickworks.(6) There is currently one brickwork 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 and shale gas from the Carboniferous Lower Limestone Shales. Applications for permission to undertake geophysical and borehole exploration continue to be made.

4 Source: 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. TRM 3: Other Minerals (2012) Kent County Council 3 2

2 Other Minerals Minerals Other

2.0.1 The range of economic minerals found in Kent covered by 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 TRM 3: Other Minerals (2012)

3 Clay Clay 3.1 Introduction and History of Clay Working in Kent 3

3.1.1 There are four principle clay horizons in Kent

London Clay.

Gault Clay.

Weald Clay.

Wadhurst Clay.

Existing Clay Permissions and Brickworks

Norwood Quarry

Smeeth Dean Works

Park Farm Wrotham Greatness Quarry Winterbourne Quarry East

Chiddingstone Brickyard Babylon Tile Works Staplehurst Brickworks Naccolt Brickworks Pluckley Brickworks (Hanson)

Frittenden Brickworks

Major Clay Horizons " Clay - Brick ! Ckay - Other Brickworks

London Clay 0 5 10 20 30 Kilometers Gault Clay ± Weald Clay Note: All Clay permissions are dormant except Norwood , Babylon and Greatness (C) Crown Copyright. All rights reserved 100019238, 2010 Wadhurst Clay

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

3.1.3 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. TRM 3: Other Minerals (2012) Kent County Council 5 3 3.1.4 Weald Clay still supports a large brickmaking industry in the Wealden district Clay (which covers parts of Kent, Surrey, East and West Sussex).

3.1.5 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 geological memoirs.(7)(8) The geology of the Weald with its heavily faulted centre(9) 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.

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

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

3.2 Brickearth

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.

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. 6 Kent County Council TRM 3: Other Minerals (2012)

3.2.1 Brickearth is a superficial deposit that overlies the Chalk and Tertiary deposits of North Kent. The deposits are wind formed loess (10) and have a high quartz content. Clay The deposits of brickearth also contain calcite which is the reason for the yellow hue 3 of bricks manufactured from it. If calcite is absent or low in content the brickmakers added ground chalk to maintain the yellow colour. The deposits are not very thick (between 1 and 3 metres in Kent) 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’(11) 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 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 continue manufacturing the London stock brick.

3.2.4 It would appear from discussions with industry in 2010/11 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 remaining operational brickworks, Smeed Dean, 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.

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,

10 See Appendix 2: Glossary 11 Source: http://www.faversham.org/history/More_History/brickmaking.aspx TRM 3: Other Minerals (2012) Kent County Council 7 3 the brickearth available would be sufficient for 9.67 years production”. On this Clay 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:

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. Recent returns (2011) suggest the life of this extraction site will last until 2014.

To secure a 25 year supply from the beginning of 2012 would mean identifying resources for a further 16 years, of 720,000 m3.

(It has been confirmed by the Company in writing (March 2012) that the reserves identified in the May 2011 topic report at Quinton Road, Sittingbourne (SW/78/1342) are no longer available. As a consequence of this information these reserves have been removed from the landbank.)

Ospringe Brickworks

The works, until 2009, 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.

The permitted sites and potential brickearth workings identified at Ospringe in 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 confirmed they have 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(12) the brickworks site has been included within a proposed employment site known as the Western Link, Faversham with attached Policies B2, B14 and B15. The Swale Borough Local Plan, subject to

12 Swale Borough Local Plan (Adopted February 2008) 8 Kent County Council TRM 3: Other Minerals (2012)

new brickearth resources being identified, would support the continued use of the brickworks at the current location or some other suitable location appropriately Clay located to the new raw material source. 3

3.2.6 In the Kent Minerals Subject Plan Brickearth (13) in addition to the “dedicated” permitted reserves identified in para. 3.2.6 above, there are a number of “potential brickearth workings” that have been previously promoted by the brick industry but not worked (all are identified in Table 1). Set against current and expected usage, together they constitute a very considerable resource.

3.2.7 Table 1: Potential Brickearth Workings in Kent (Includes: those identified in the Kent Minerals Subject Plan Brickearth Written Statement May 1986 which remain unworked as at the beginning of 2012, a registered dormant site, and earlier permissions for brickearth working which have now lapsed.)

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

BE6. West Tonge Farm 45,000 m3

BE7. Claxfield Farm 69,000 m3

BE8. Barrow Green 205,000 m3

BE9. Barrow Green Extension 120,000 m3

BE10. Hempstead House 35,000 m3

Total 1,865,000 m

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

13 Kent Minerals Subject Plan Brickearth Written Statement May 1986 TRM 3: Other Minerals (2012) Kent County Council 9 3 3.2.8 Although brickearth deposits occur south of the Chalk escarpment, they are Clay 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).

3.2.9 Following the call for sites exercise in 2011, 5 brickearth sites have been promoted for inclusion in the Minerals Development Plan Document by two brick companies and one landowner. These sites are listed in Table 2.

3.2.10 Table 2 Existing Reserves and Promoted Brickearth Workings in Kent

Location Estimated Reserves (tonnes) (all in Swale borough) (Conversion Factor = 1.68 tonnes/m3)†

Newington Area

Site 19. Paradise Farm 678,000

Teynham Area

Claxfield Farm (Existing consented 138,000 reserves)

Hempstead House (Existing consented 80,000 reserves)

Site 19 Land at Bax Farm Undisclosed

Site 98 Jeffries Farm* 95,000

Site 101 Barbary Farm near Faversham 1,241,000

Site 102 Barrow Green 760,000

Total 2,992,000

1. *All of the sites in Table 2 except Jeffries Farm have been allocated in previous Development Plans.

2. †Conversion factor derived from Engineering Properties of Soils and Rocks (14)

3.2.11 Ibstock Brick Limited (Hempstead House) and Wienerberger Limited (Claxfield Farm) continue to produce traditional stockbricks at their Ashdown Brickworks, East Sussex and Sittingbourne brickworks respectively.

14 Fred G Bell Engineering Properties of Soils and Rocks 4th Edition 2000 10 Kent County Council TRM 3: Other Minerals (2012)

3.3 Brick Clay

Clay 3.3.1 There is only one operational brick clay operation in the County, a Kent peg 3 tile works near Hawkenbury (Babylon Tile Works).

3.3.2 The tile works situated south of Maidstone utilises Weald Clay as its raw material. This is a small 'cottage' industry that manufactures traditional hand made Kent peg tiles. The current planning permission requires extraction to cease by April 2022 and for Kent peg tile manufacture 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 beyond 2022.

Kiln at Babylon Tile Works

3.3.3 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 brickworks building is for sale and the shale tip has been sold. TRM 3: Other Minerals (2012) Kent County Council 11 3 Former Tilmanstone Brickworks Clay

3.3.4 Tilmanstone Brickworks was a modern facility that was granted planning permission on 6th October 1989 at the former Tilmanstone Colliery site. 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. This factory transported its Weald Clay over 40 kilometres and Gault Clay over 60 kilometres to the factory. Substantial reserves of Weald Clay remain in the ground at the former Pluckley brickworks site but no in situ reserves of Gault Clay, there are some reserves of both currently stockpiled at Tilmanstone.

3.3.5 However, it has suffered from the recent recession and the plant was closed in 2009 and the brick making machinery removed from the building. The building and its immediate surroundings have been put up for sale. It currently seems unlikely that it will re-open as a brickworks.

3.3.6 The reserves of Weald Clay at Pluckley were estimated to be in excess of 1 million m3 in January 2008, with an annual consumption of 20,000 m3. Hanson have confirmed they have sold the land but have retained the mineral rights without the right to work. 12 Kent County Council TRM 3: Other Minerals (2012)

3.3.7 The closure of the brickworks means it is unlikely that additional Gault Clay reserves will need to be identified to enable the long term continuation of yellow brick Clay production at Tilmanstone. 3 3.3.8 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 (1 - Gault Clay and 3 - Weald Clay), though it is doubtful whether any of these sites will be worked again (see Table 3).

TABLE 3 PERMITTED CLAY RESERVES IN KENT

Permitted Reserves at Quarry Geology (Use) 1/1/2012 (cubic metres (m3))

North Kent

London Clay Norwood (Swale) 50,000 (Engineering)

East Kent

Naccolt Brickworks Gault Clay (Brick) 1,790,0002 (Ashford)

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

Mid and South West Kent

Chiddingstone (Sevenoaks) Weald Clay (Brick) 270,0002

Frittenden (Tunbridge Weald Clay (Brick) 650,0002 Wells)

Clay at this site is required Greatness (Sevenoaks) Gault Clay (Brick) for the engineering of the landfill on its completion.

Park Farm (Tunbridge & Gault Clay (Cement) 2,000,0001 Malling)

Pluckley (Ashford) Weald Clay (Brick) 1,000,0003

Staplehurst (Maidstone) Weald Clay (Brick) 200,000

Total 6,960,000 TRM 3: Other Minerals (2012) Kent County Council 13 3 Notes: Clay

*Source - Planning application files and Kent Minerals Local Plan Chalk & Clay(15)

Sites in italics have been dormant for over 10 years except Pluckley (See note 3 below)

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

2Mineral Planning Authority estimate, as set out in the adopted Minerals Local Plan (Table 9.1 on page 40) (16) No recent working has taken place.

3With the closure of Tilmanstone Brickworks this site has now been dormant for 2 years (See paragraph 3.3.6 above).

3.3.9 Table 4 below shows the declared tonnages from the National Statistics Office for sales of clay sold in Kent for brick, tile, engineering and other uses. The number of years of 'non-returns' is indicative of the lack of multiple active sites, which results in the disclosure rule being applied (The Statistics of Trade Act 1947).

TABLE 4 CLAY FOR BRICK, TILE, ENGINEERING AND OTHER USES

Year 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Brick & 124,000 **** 103,000 85,000 *** Tile

Engineering 42,000 69,000 39,000 57,000 * 1,000 1,000 - 33,000 - & Other

Total 166,000 *** 115,000 104,000 86,000 ***

15 Kent Minerals Local Plan Chalk and Clay/Oil and Gas Adopted December 1997. 16 Kent Minerals Local Plan Chalk and Clay/Oil and Gas Adopted December 1997. 14 Kent County Council TRM 3: Other Minerals (2012)

1. Source - National Statistics, Business Monitor PA1007 Table 8. (Note: the National Statistics Business Monitor does not identify Medway in its list of Clay Authorities for South East England, it is therefore possible that the figures in the 3 table include some production from Medway, although this is considered unlikely as there are no operational brickworks in Medway.)

2. *withheld to avoid disclosure

3. nil or less than 500 tonnes

3.3.10 In addition to the permitted reserves for the works identified in paragraphs 3.3.1 to 3.3.8 above and in Chapter 4 as a cement making material, Kent has a number of 'freestanding' clay working permissions (Table 3) . Some of the clay permissions are very old and have not been worked for many years and could not be re-opened without considerable work on agreeing new ROMP conditions. They are therefore not available for consideration within the Kent landbank.

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 required solely for on-site engineering works associated with the restoration of the landfill site.

3.4.3 Permitted 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 over the last twenty years or so.

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. In view of the current situation regarding clay for engineering works being sourced from only one Kent site in recent years, it may be necessary to identify a site as a preferred option for the continued supply of clay for engineering uses.

3.4.5 From the National Statistics, Business Monitor PA2007, the following extract from Table 4 illustrates the level of activity of clay used for construction purposes from 2000 to 2010 inclusive: TRM 3: Other Minerals (2012) Kent County Council 15 3 Table 4 B: CLAY USED FOR CONSTRUCTION AND OTHER PURPOSES IN Clay KENT. ( SALES IN TONNES)

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

* 42,000 69,000 39,000 57,000 1,000* -1,000 33,000 -

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)

*withheld to avoid disclosure

- nil or less than 500 tonnes

3.4.6 The figures in Table 4 indicate an average use of approximately 27,000 tonnes per annum for the last 11 years using data for the years when records were available (i.e. the *years which were withheld in the above table were not included in this calculation). If these figures were projected until the end of the plan the total clay required would be approximately 486,000 tonnes. With less than 50,000 tonnes remaining in the one operational site, it is projected from these figures that circa 440,000 tonnes of clay will be required

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:(17) into 4 groups(18)

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.

17 See Appendix 2: Glossary 18 See www.galleries.com/minerals/silicate/clays.htm 16 Kent County Council TRM 3: Other Minerals (2012)

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 uses. Therefore Kent clays do not have a major use for specialist industrial use.

3.5.7 One exception to this lack of industrial use is the Fullers Earth deposits around Maidstone, which 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(19) The last operation to extract Fullers Earth was undertaken near Grove Green in Maidstone by Laporte Industries Ltd.

3.5.9 Since the closure in the1970's of Laporte's Grove Green site, Fullers Earth deposits are no longer commercially exploited in Kent.

19 See B.C. Worssam (1963) Geology of the Country around Maidstone. Geological Survey of Great Britain. TRM 3: Other Minerals (2012) Kent County Council 17 4

4 Chalk Chalk

4.1 Chalk Geology

4.1.1 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 subsidiary horizons the Glauconitic Marl at the base of the Chalk Marl and the Melbourn Rock at the base of the Middle Chalk.

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

4.1.2 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.

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

4.1.4 The Lower Chalk or Chalk Marl is an impure limestone that contains a high proportion of argillaceous(20) and arenaceous(21) 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 metres 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.

20 See Appendix 2: Glossary 21 See Appendix 2: Glossary. 18 Kent County Council TRM 3: Other Minerals (2012)

4.1.5 The Middle Chalk is a massive(22) rock with little contamination being almost entirely calcium carbonate with the exception of the layers of flint nodules. It is marked

Chalk at the base by the Melbourn Rock and is characterised in the upper part of the

4 formation by the presence of flint nodules. It is the Middle Chalk that forms the 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.

4.1.6 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.

4.1.7 The Middle and Upper Chalk are much purer forms of limestone than the Lower Chalk.

4.2 Cement

4.2.1 In Kent the cement industry established itself on the banks of the Thames and Medway estuaries utilising the local resources of chalk and clay(23)

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

4.2.3 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.

4.2.4 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.

4.2.5 At present there are no cement works in Kent, despite there being a planning permission (TM/98/785) for a major new plant at Holborough near Snodland granted on 26th November 2001 (see Map in Section 4.1 Chalk Geology).

22 See Appendix 2: Glossary 23 See: http://www.cementindustry.co.uk/the_industry/profile.aspx TRM 3: Other Minerals (2012) Kent County Council 19 4 4.2.6 If constructed, this cement works would have an approximate life of 35 years Chalk producing 1.4 million tonnes per annum (m.t.p.a.) utilising 72 million tonnes of raw material.

4.2.7 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).

4.3 Agricultural Lime

4.3.1 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 usage of some 80,000 tonnes per year (tpa). At that time it was concluded that, unless large areas of land were to be permanently removed from agricultural production by set aside or other means, current consumption of agricultural lime was unlikely to alter significantly.

4.3.2 However since then, sales of chalk for agricultural use have been at a much lower level. Table 5 shows sales since 2002 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. The last three years have seen a minor average increase of approximately 6,000 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 1,134,000 tonnes of chalk for agricultural use, but using the average of the last 10 years (45,300 tpa) it would need a reserve of 816,000 tonnes.

TABLE 5 CHALK – KENT EXTRACTORS’ SALES FOR AGRICULTURAL AND ENGINEERING USE. Year 20032002 2004 2005 2006 2007 2008 2009 2010 2011 Agricultural 48,000* 39,00037,000 63,000 39,00042,000 47,000 47000 46000 Use Engineering nilnilnilnil 90,000 5,000? 349,00050,000156,000 Use Total 48,000* 39,00037,000153,00039,00047,000396,00097,000202,000 Sales

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

Withheld to avoid disclosure. 20 Kent County Council TRM 3: Other Minerals (2012)

4.3.3 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

Chalk about production and reserves given in planning applications and more recently

4 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 1/1/2012

North Kent

CH1. Darenth Road Quarry (Dartford) 500,000

CH2. Pinden Quarry (Dartford) 1,230,000

Mid and South West Kent

CH3. Detling Quarry (Maidstone) 150,000

East Kent

CH4. Beacon Hill Quarry (Ashford) 320,000

CH5. Brabourne (Canterbury) Nil

CH7. Crundale Quarry (Ashford) 250,000

CH8. Hegdale Quarry (Ashford) 100,000

CH9. Rowling Quarry (Dover) 84,000

Total Permitted Reserves 2,634,000

Source – planning application files and consultation with the producing companies.

Location of the chalk quarries is shown on the map in Section 4.1 Chalk Permissions and Geology

4.3.4 Permitted chalk reserves, of more than 2.634 million tonnes, 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. TRM 3: Other Minerals (2012) Kent County Council 21 4 4.4 High Purity and Engineering Chalk Chalk

4.4.1 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.

4.4.2 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 National Statistics 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.

4.4.3 However, national statistics (see table 7) recorded no sales of Kent chalk for engineering (industrial) uses between 2002 and 2005. The statistics also identify only a very small amount of chalk as having been sold for construction uses (normally 2,000 -3,000 tonnes per year until 2006 when 90,000 tonnes were recorded as having been sold. Since 2006, sales of chalk for engineering use have fluctuated from a low of 5,000 tonnes to a high of 349,000 tonnes due to a number of high profile infrastructure projects. Examples of these infrastructure projects include the A2/M25 junction improvement, Eastern Quarry, Bluewater, Stone Pit II and Burham.

4.4.4 As a result of this marked change in demand it would appear appropriate that some provision for additional chalk resources is made within the plan period. As a significant percentage of this usage of chalk is in North West Kent, this should be the target area for future provision.

TABLE 7: CHALK – KENT EXTRACTORS’ SALES FOR ENGINEERING USES 2002Year 2003 2004 2005 2006 2007 2008 2009 2010 2011 Sales nilnilnilnil 90,000 5,000? 349,000 50,000 156,000

Source – National Statistics, Business Monitor, PA1007, Table 9 and returns from a KCC chalk operator survey.

Note: Sales less than 5,000 tonnes per year are recorded as ‘nil’

4.4.5 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 22 Kent County Council TRM 3: Other Minerals (2012)

from adhesives & sealants, building products, glass, paints & inks, paper, plastic & rubber to animal feeds, flue-gas desulphurisation, fertilizers, food, personal care, (24)

Chalk pharmaceuticals and water treatment 4 4.4.6 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 PA1007, Table 9 in 2010.

4.4.7 A survey of chalk sales for the 2011 calendar year carried out in March 2012 has identified that a total of 203,480 tonnes of chalk were sold from six of the sites listed in table 6.

24 http://www.calcium-carbonate.org.uk/calcium-carbonate/caco3-applications TRM 3: Other Minerals (2012) Kent County Council 23 5

5 Silica Sand Sand Silica

5.2.1 Silica sand is the subject of a separate joint topic report with Surrey County Council, written by GWP and published March 2010.(25)

5.2.2 The silica sand topic report in conjunction with Government Policy will provide the policy basis for this mineral.

25 GWP Consultants (2010) A Study of Silica Sand Quality and End Uses in Surrey and Kent. 24 Kent County Council TRM 3: Other Minerals (2012)

6 Energy Minerals

6.1 Introduction

6.1.1 Energy minerals are the natural minerals found in the ground that provide us with heat and power. They are normally 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. Energy Minerals

6 6.1.2 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 always apply in the case of oil shales).

6.2 Coal Deposits in Kent

6.2.1 East Kent Coalfield

East Kent Coalfield and Former Colliery Sites.

Chislet (Hersden)

Betteshanger Snowdown Tilmanstone

Legend Kent Coal Mines ± Kent Coalfield

0 5 10 20 Kilometers

6.2.1.1 The East Kent Coalfield is a concealed coalfield that underlies the Cretaceous rocks that appear at the surface in Kent. Exploration of this coalfield began in the 19th Century and its areal extent is indicated on the map above. TRM 3: Other Minerals (2012) Kent County Council 25 6 6.2.1.2 The East Kent Coalfield was exploited for its coal reserves from 1912 when nryMinerals Energy 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 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.(26)

6.2.1.3 The East Kent Coalfield covers an area of approximately 157,900 hectares (1579 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 towards the periphery of the outcrop due to its synclinal form (27). Of the 36 seams identified in the West Court Farm borehole (near Shepherdswell) 12 were at least 0.4 metres thick with one being logged at 2.36 metres thick.(28)

6.2.1.4 Kent coal was bituminous(29) to semi-anthracitic(30) 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.

6.2.1.5 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.

6.2.1.6 The Coal Authority had 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. However the Coal Authority has confirmed that Dysart Coal Mine Management Pty Ltd has made 5 conditional underground licence applications to investigate the East Kent Coalfield.

6.2.1.7 TheCoal Authority licence applications are for the Kent Coalfield Redevelopment Project applied for by Dysart Coal Mine Management Pty Ltd (an Australian company) and relate to a proposed underground mining prospect. They are applications for conditional licences and there are 5 because the Coal Authority has a licence area limit of 10,000 hectares. The licences are still being processed at the time of writing this report and have not been granted yet.

26 See http://doverdc.co.uk/kentcoal/intro.asp 27 See Appendix 2: Glossary 28 J. G. O. Smart et al (1966) Geology of the Country around Canterbury and Folkestone. 29 Appendix 2: Glossary 30 Appendix 2: Glossary 26 Kent County Council TRM 3: Other Minerals (2012)

6.2.1.8 A conditional underground licence does not immediately give an operator the power to mine coal and is conditional on other rights and permissions being granted, most notably planning permission and surface access rights for the mine site etc. A conditional licence lasts initially for a maximum term of 8 years (normally 5) and the term is only extended if progress is made in developing the project.

6.2.2 Coal Bed Methane

Energy Minerals 6.2.2.1 Coal bed methane (CBM) is natural methane trapped within the coal seams 6 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(31) are brown, bituminous and anthracite. The density of bituminous coal is between 1.12 and 1.3 tonnes/m3 whilst anthracitic coal is denser at 1.3 to 1.6 tonnes/m3.(32) The quantity of CBM generated will vary from coal seam to coal seam.

6.2.2.2 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.

6.2.2.3 Current thinking(33) suggests coal seams need to be at least 0.4 metres thick to be economic to be developed for coal bed methane. The West Court Farm borehole near Shepherdswell identified 12 seams that met this criteria.

6.2.2.4 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.

6.2.2.5 To extract coal bed methane, a series of boreholes need to be drilled, normally to a pattern defined by previous exploratory and development drilling that has tested the coal seams in order to understand and prove its potential for methane extraction.

6.2.2.6 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.

6.2.2.7 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.

31 See Appendix 2: Glossary. 32 Terex Reference Booklet (1978). 33 http://www.composite-energy.co.uk/drilling-cbm.html TRM 3: Other Minerals (2012) Kent County Council 27 6 6.2.2.8 In April 2011, Kent County Council received a planning application nryMinerals Energy (DO/11/339) to drill an exploratory borehole to test the in situ coals, Lower Limestone Shales and associated strata.

6.2.2.9 Permission was granted for the drilling of the exploratory borehole on the 6th December 2011.

6.2.2.10 The Department of Energy and Climate Change published a document in 2010(34) that commented on each coal basin in the UK. This report stated that the East Kent Coalfield measured gas content was low based on tests conducted on Kent 6 seam from the face at Tilmanstone Colliery, despite the rank of the coal(35) A possible reason for this anomaly has been the potential for the gas to migrate from the coal seams through the multiple unconformities on the NE margin of the basin and the permeable nature of the overlying sandstones and limestones of the Weald Basin.

6.2.3 Underground Coal Gasification

6.2.3.1 The Department of Energy and Climate Change has provided information on its website on the subject of underground coal gasification (36). The concept is to gasify coal underground and bring the energy to the surface as a gas for subsequent use in heating or power generation. It requires precision drilling of two boreholes, one to supply oxygen and water/steam, the other to bring the product gas back to the surface.

6.2.3.2 The gas brought to the surface may be used for industrial heating or power generation or the manufacture of hydrogen, synthetic natural gas or other chemicals.

6.2.3.3 The concept of coal gasification began in Russia in the 1930s. Britain began research in the 1950s with a long term trial at Newman Spinney, Derbyshire. US trials in the 1970s tested new oil and gas technology to control the process developed in the oil industry. Between 1992 and 1999, the Underground Gasification Europe (UGE) project was undertaken in Spain, part sponsored by the UK's Department of Trade and Industry, European Union, Spain and Belgium, to test directional drilling at depth and it concluded that UCG wells in deep coal seams could be successfully constructed.

6.2.3.4 Following the results of the Spanish project, a decision was taken by the UK government to undertake further research independently. Energy Paper 67 (37) identified a number of issues on which to undertake research:

Improving the accuracy of in-seam drilling Examining the implications of burning UCG gas in gas turbines

34 The Unconventional Hydrocarbon Resources of Britain's Onshore Basins - Coalbed Methane (CBM) DECC 2010. 35 See Appendix 2: Glossary. 36 http://coal.decc.gov.uk/en/coal/cms/publications/mining/gasification/gasification.aspx 37 Energy Paper 67 Cleaner Coal Technologies Departmant of Trade and Industry 1999 28 Kent County Council TRM 3: Other Minerals (2012)

Estimating the landward coal reserves for UCG Identifying a semi-commercial site Establishing cost parameters for the process to be competitive Carrying out a pre-feasibility study of offshore exploitation of UCG The aim was to achieve these goals, in association with industry, over the next six years.

6.2.3.5 In 2009 and 2010, an increased level of interest arose in the prospect of Energy Minerals

6 UCG and during this time 14 conditional near shore UGC licences were issued to companies keen to pursue this technology in Great Britain. These conditional licences enable prospective operators to secure the rights to the coal while projects are developed but do not permit UCG operations to commence until all other rights and permissions are in place.

6.2.3.6 There has been a Notice Inviting Applications for Rights and Interests in Coal publicised on 26th May 2010 for a conditional underground coal gasification licence for an offshore area to the north of the Isles of Grain and Sheppey. This is not an area known to contain reserves of coal but an application has been received nonetheless to explore this area.

6.2.3.7 No permission to undertake this exploratory drilling has yet been given. A licence once approved lasts for three years. This is the only application for underground coal gasification exploration within or offshore for the County of Kent.

6.3 Oil

6.3.1 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(38) 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 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.

6.3.2 The Crown owns the following minerals - oil, gas, coal, gold and silver,(39) whereas other minerals are owned by the surface landowner or held by third parties who have purchased or inherited the mineral rights. Crown property is administered for the Government by the Crown Estates. Companies, who wish to exploit the Crown minerals, are invited to bid for licences by the Government.

38 See Petroleum Geological Atlas of the Southern Permian Basin Area British Geological Survey, Geological Survey of Belgium et.al. (eage.org). 39 http://www.bgs.ac.uk/mineralsuk/planning/legislation/mineralOwnership.html TRM 3: Other Minerals (2012) Kent County Council 29 6 6.3.3 The 1997 Kent Minerals Local Plan Chalk and Clay /Oil and Gas(40) detailed nryMinerals Energy the process and procedure for licensing, prospecting and developing economic oil and gas deposits. Oil and gas licences are controlled by the Department of Energy and Climate Change. On 7th November 2007, the Secretary of State for the Department 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

6.3.4 Kent County Council has a regulatory role in the determination of planning applications to drill the exploration boreholes and in subsequent appraisal and production development.

6.3.5 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.

6.3.6 An exploratory borehole was also drilled in August 1999 at Cowden near Tunbridge Wells (SE/98/234). Cuadrilla Resources Ltd were recently granted planning consent (SE/11/1396) on 12 July 2011 to undertake further tests on the capped well at Cowden to establish the extent and production capability of the field. Drilling has

40 Kent Minerals Local Plan Chalk and Clay/Oil and Gas (1997). 30 Kent County Council TRM 3: Other Minerals (2012)

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.

6.3.7 Another small oil field in Surrey close to the border with Kent is near Oxted and is operated by Star Energy

6.3.8 Oil exploration is undertaken in two different forms,geophysical exploration Energy Minerals and borehole drilling programmes. Geophysical exploration is the practical application 6 of physical methods (such as seismic, gravitational, magnetic, electrical and electromagnetic) to measure the physical properties of rocks, and in particular, to detect the measurable physical differences between rocks that contain hydrocarbons and those without. Geophysical exploration is often used in the first instance to identify potential areas of interest for oil and gas reservoirs and then these areas are tested by the drilling of exploration boreholes. Identification of potential areas does not guarantee the presence of oil or gas.

6.4 Natural Gas

6.4.1 Minor reserves have been exploited in the past (1885 and 1896) near Heathfield, East Sussex (41) 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.

6.4.2 Natural gas exploration and extraction is undertaken in a similar way to oil exploration.

41 British Geological Survey (1965) British Regional Geology The Wealden District 4th Edition. TRM 3: Other Minerals (2012) Kent County Council 31 7

7 Natural Building and Roofing Stone Stone Roofing and Building Natural

Natural Building Stone Outcrops in Kent.

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

7.0.1 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.(42)

7.0.2 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, Bearsted and Furfield Quarry near Park Wood in Maidstone have been redeveloped for housing or restored by landfill respectively.

7.0.3 Other sites where building stone has been extracted historically 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.

42 Appendix 2: Glossary 32 Kent County Council TRM 3: Other Minerals (2012)

7.0.4 Ragstone is Kent's best known building stone.(43) 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.

7.0.5 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. Stone for repair and maintenance must be compatible with the original for technical reasons – the wrong stone can hasten future damage - and for aesthetic reasons – the wrong stone may harm the appearance of the structure. Therefore it is essential to secure stone from either the original source or a closely similar source. To do that we need to know where particular building or roofing stones were originally worked and be able to obtain planning permission to extract more stone when (44) Natural Building and Roofing Stone required 7 Ragstone Retaining Wall at Springfield roundabout Maidstone.

43 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). 44 English Stone Forum: http://www.englishstone.org.uk/ TRM 3: Other Minerals (2012) Kent County Council 33 7 7.0.6 In addition to Ragstone, Tunbridge Wells Sandstone, Bethersden Marble aua uligadRoigStone Roofing and Building Natural 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. Calcareous tufa, found in small outcrops near Ditton, has been used in a few buildings, 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.

7.0.7 The Strategic Stone Study (SSS) was set up in response to the Symonds Report Planning for the Supply of Natural Building and Roofing Stone in England and Wales published in 2004 by the then Office of the Deputy Prime Minister (now Department of Communities and Local Government )(45) This report examined the issues affecting the supply of and demand for indigenous building stone in the UK. In particular, the report focused on the problems of sourcing appropriate stone to repair historic buildings and recommended that Mineral Planning Authorities should identify and protect 'heritage quarries'.

7.0.8 The Strategic Stone Study recommended that a freely available web based national database of the building and roofing stones be established and managed by the British Geological Survey to include:

a description of the stones;

an indication of their suitability for various end uses;

details of existing sources;

information on the extent of unworked resources, including disused/dormant quarries, outcrop limits and the likely extent of each rock unit.

7.0.9 English Heritage have commissioned an experienced local geologist and a historic buildings expert for each of the counties surveyed to date. Kent was added to the list of Counties that have been surveyed as part of this national study in October 2011.(46)

7.0.10 The Kent Strategic Stone Study lists all the types of stone that have been used in building construction. It commences with the oldest formation (Ashdown Formation) that outcrops in Kent through the Geological Column to the present day.

7.0.11 Gallagher Aggregates Limited have commissioned an independent study of their Hermitage Quarry to identify the different beds within the deposit in order that future conservation projects may be able to compare the stone being replaced in a

45 See www.bgs.ac.uk/mineralsuk/mines/stones/EH_safeguarding_stone 46 Access to the information, held in the database, may be made through the following web address: www.bgs.ac.uk/mineralsuk/mines/stones/EH_project.html 34 Kent County Council TRM 3: Other Minerals (2012)

historic building with the available stone in the quarry and thus identify the most appropriate stone for the repair work. This work will include the identification of historic marker beds such as the 'Flint' and the 'Black Jack' within the quarry and produce a classification of the intermediate beds in order to refine the choice of suitable building stone into the future.

7.0.12 The study is being undertaken by two consultants, who specialise in ragstone geology and the engineering properties of building stone respectively. Natural Building and Roofing Stone 7 TRM 3: Other Minerals (2012) Kent County Council 35 8

8 References 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 Geological Survey.

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. Fred G Bell Engineering Properties of Soils and Rocks 4th Edition 2000

10. Kent Minerals Local Plan Chalk and Clay/Oil and Gas (Adopted December 1997). Kent County Council

11. John Newman. West Kent and the Weald. The “Buildings of England” Series, First Edition, Sir Nikolaus Pevsner and Judy Nairn, eds. (London: Penguin, 1969),

12. E.R. Shepherd-Thorn (1988) Geology of the Country around Ramsgate and Dover. Geological Survey of Great Britain

13. J.G.O. Smart et.al (1966) Geology of the Country around Canterbury and Folkestone. Geological Survey of Great Britain

14. B.C. Worssam (1963) Geology of the Country around Maidstone. Geological Survey of Great Britain

15. http://www.calcium-carbonate.org.uk/

16. http://www.cementindustry.co.uk/the_industry/profile.asp

17. https://www.og.decc.gov.uk/ 36 Kent County Council TRM 3: Other Minerals (2012)

18. http://doverdc.co.uk/kentcoal/intro.aspx

19. http://www.composite-energy.co.uk/about-cbm.html Source of data on coal bed methane.

References 20. http://www.medwaypilots.co.uk/page2.Htm 8 21. http://www.galleries.com/minerals/silicate/clays.htm

22. Petroleum Geological Atlas of the Southern Permian Basin Area British Geological Survey, Geological Survey of Belgium et.al. (eage.org)

23. The Unconventional Hydrocarbon Resources of Britain's Onshore Basins - Coalbed Methane (CBM) DECC 2010.

24. Office of the Deputy Prime Minister (March 2004) Planning for the Supply of Natural Building and Roofing Stone in England and Wales.

25. Department of Trade and Industry (1999) Energy Paper 67 Cleaner Coal Technologies TRM 3: Other Minerals (2012) Kent County Council 37 pedx1: Appendix Appendix 1: Planning Permissions

7 Brickearth Planning Permissions

Planning Permission Quarry Decision Date

North Kent Permissions Planning

NK/9/60/79* Libbetwell North 05.09.1960

SW/86/859 Libbetwell South 25.01.1988

SW/04/823/MR03 Claxfield Farm 30.03.2005

SW/03/430 Hempstead House 15.09.2003

SW/81/1064* Barrow Green 15.03.1982

South West Kent

TW/92/6000 Frittenden Brickworks 11.05.1994

* There is no evidence to confirm that these two planning permissions were implemented.

Table 8 Clay Permissions

Planning Quarry Decision Date Permission

North Kent

SW/05/744 Norwood Quarry 24.11.2005

East Kent

SW/97/580/MR76 Winterbourne Quarry 24.10.1997

AS/92/360 Naccolt Brickworks 08.05.1992

Mid and South West Kent

SE/91/1989 Chiddingstone Brickworks 24.11.1993

TW/92/6000 Frittenden Brickworks 11.05.1994

TM/02/2663/MR97 Park Farm (Cement) 03.03.2003

MK/3/48/12 Staplehurst Brickworks 02.09/1948

AS/93/1204 Pluckley Brickworks 29.04.1994 38 Kent County Council TRM 3: Other Minerals (2012)

Table 8 Clay Permissions

MA/04/1168/MR43 Babylon Tile Works 19.11.2004

Table 9 Chalk Planning Permissions

Planning Quarry Decision Date Permission

North Kent Planning Permissions 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 Appendix 1: MA/04/335/MR42 Detling Quarry Detling (Maidstone) 09.02.2005

TM/98/785 Holborough Cement Works 26.11.2001

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) TRM 3: Other Minerals (2012) Kent County Council 39 pedx2: Appendix Appendix 2: Glossary

Glossary

Anthracite, A hard natural coal that burns slowly and gives intense heat, the Glossary -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 coal smoky 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)

Carboniferous A period lasting approximately 60 million years during which time the Carboniferous limestone and the Coal Measures were formed. It is one of the periods of the Palaeozoic era starting 360 million years ago and finishing 300 million years ago. It is noted for the first large primitive trees, land vertebrates and winged insects.

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. 40 Kent County Council TRM 3: Other Minerals (2012)

Drift In the UK the term drift is commonly used to describe any deposits of quaternary age. (Geology) Glossary E

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

F Appendix 2: 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.

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.

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 X 107 to 1.93 107 J/kg (5500 to 8300 Btu/lb) Also called brown coal. TRM 3: Other Minerals (2012) Kent County Council 41 pedx2: Appendix Loess Loess is a geologic term that refers to deposits of silt (sediment with particles 2-64 microns in diameter) that have been laid down by wind action, alternatively described as a deposit of yellowish-grey fine loam.

M Glossary 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 A person who studies the distribution, identification, and properties of rocks, gems and minerals.

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

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 Valuable and legally and economically and technically feasible to extract.

Resource Potentially valuable, and for which reasonable prospects exist for eventual economic extraction. 42 Kent County Council TRM 3: Other Minerals (2012)

Solid geology Is defined by the British Geological Survey as the mappable rocks laid out in a stratigraphical column in sequential order with the Glossary 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

Appendix 2: 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

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