5th February 2017: Walked up through Harptree combe towards Garrow Bottom. Passing the aqueduct, built c.1840's, on the way. The weather, low cloud but, quite mild.
From Garrow Bottom followed a feint path, up the bank and through the woods to Smitham minery and the chimney. This is the last chimney remaining from the lead smelting industry on Mendip.
The chimney was built in 1867 by Cornish engineers. The smelting ceased in 1875 and a year later all the buildings, except the chimney demolished. The chimney was restored by the Mendip Society in the 1970's.
From the chimney, followed the paths through the woods towards the car park, taking a detour to take a look at an old cave dig in one of the depressions. Water has been sinking here quite recently.
Across the road and into the field where Wurt Pit is located at NGR ST 558539.
The SSSI is an impressive site, it is one of the largest subsidence depressions in the Mendips. The silica-enrichment of the limetones and clays at Wurt Pit (known as the Harptree Beds, of early Jurassic age) is of considerable mineralogical importance since it took place as part of the main phase of mineralisation which emplaced the principal Mendip orefields during Jurassic times. The Harptree Beds show varying degrees of silica-enrichment, and also contain traces of other minerals, such as limonite and yellow ochre (hydrous ferric oxides), barite (barium sulphate), sphalerite (zinc sulphide) and galena (lead sulphide).
There are some good exposures of the rock type, access can be slippery when wet. The site falls within the Mendip Hills AONB.