Mendips header
 Overview maps
 Locality areas
  Cheddar Gorge
 Burrington Combe
 Shipham & Rowberrow
 Crook Peak & Axbridge
 Banwell to Churchill
 Harptree & Smitham Hill
 Draycott & Westbury-sub
 Wookey Hole & Ebbor
 Great Elm & Vallis Vale
 Mells & the Wadbury Valley
 The Vobster area
 The Whatley area
 Torr Works & Asham Wood
 Beacon Hill
 Stoke St Michael & Oakhill
 Holwell & Nunney
 Shepton Mallet & Maesbury
 Gurney Slade & Emborough
 The Nettlebridge valley
 Rocks of Mendips
 Geological timescale
 Ancient environments
 Geological structure
 Minerals and mines
  Minerals and mines
 Industrial archaeology
  Stone as a resource
 Employment & the economy
 Quarrying & geodiversity
 Quarrying & the environment
 History of quarrying
 Caves and karst
 How caves form
 Dry valleys and gorges
 Dolines and sinkholes
 Mendip caves
 Going caving
  Flora and fauna
 Typical Mendip habitats
 Special Mendip habitats
 Horseshoe bats
 Appendix of names
 Biodiversity of western
 Biodiversity of eastern
 External links
 Detailed site information
  Coal mining
  Mendip quarry companies
  East Mendip quarries
 Biodiversity of eastern
  West Mendip quarries
 Biodiversity of western
 Site map
Harptree and Smitham Hill
East and West Harptree are located at the mouth of Harptree Combe, a narrow gorge cut into the Dolomitic Conglomerate down which a small stream flows. The gorge is a SSSI for its flora and fauna, and contains several distinct wildlife habitats including old ash woodland, rough grassland, marshy grassland and rocky crags. Half way down the combe, an aqueduct crosses the valley. This is part of network of aqueducts and tunnels feeding spring water from Chewton Mendip to the Barrow Gurney reservoirs. The top end of Harptree Combe leads up onto Smitham Hill and East Harptree Woods, an area of woodland and heath developed on the Harptree Formation.

This rock is relatively impermeable and gives rise to a very boggy acidic soil with a characteristic heathland flora.

Aqueduct, Harptree Combe, part of Bristol Water's 'Line of Works'.
  Aerial view of Harptree and Smitham Hill (click to enlarge view).

Aerial view of Harptree and Smitham Hill (click to enlarge view).

Stone wall made up of the Harptree Beds and lime mortar, supporting many plant species

Lead mining
The Harptree area was an important lead and zinc mining area. Lead ore was mined from veins in the Carboniferous Limestone around Gibbets Brow and Lamb Leer, and manganese and zinc from veins in the Dolomitic Conglomerate around Harptree Combe.

This has left a legacy of old pits, spoil heaps and shafts creating areas of pockmarked 'gruffy ground'. The lead-rich spoil heaps are home to several rare plant species. Much of the ore was processed and smelted on Smitham Hill where ore dressing and smelting works were built by the East Harptree Lead Works Company in 1867. The Smitham Chimney dates from this time and is the last old lead-smelting chimney still standing on Mendip.

Caves and karst
There are relatively few known caves in the Harptree area, but the largest, Lamb Leer Cavern was discovered in about 1674 by lead miners. The cave is 67 m deep and contains one of the largest chambers on Mendip. The area is also pockmarked with large sinkholes, particularly around the margins of the Harptree Formation. The largest is the Devil's Punch-Bowl, an impressive depression over 50 m in diameter and almost 20 m deep. These have been formed by the dissolution of Carboniferous Limestone and Dolomitic Conglomerate at depth, followed by collapse and subsidence of the cover rocks.

  Smitham Chimney, the last remaining leadworks chimney on Mendip
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