Important work on historic extractive industries has been carried out across the region since 2006. One of the most intact metal-extraction landscapes in the North West is that around Nenthead (C) in the North Pennines, which became an important centre for the lead industry. There is very little physical evidence for lead mining in the area before the early 17th century, although it is likely that there had been limited small-scale exploitation of the surface workings. Work on the Rampgill Vein, the first vein known to have been mined at Nenthead, had begun by 1692, and the site was involved with the mining and processing of lead ore continuously thereafter until the 1900s. The lead-mining landscape at Nenthead has been the focus of archaeological research and excavation since the 1980s, with the most recent work comprising detailed research and archaeological survey of eight separate areas that included the smelt mill and features related to the dressing floors at Rampgill and Smallcleugh (Town 2014), and a community-based project that was led by Northern Archaeological Associates Ltd. The latter survey covered 48 hectares and aimed to further understand the position, function, and flow paths of the water-management systems at the mines, identify threats to known archaeological remains, and inform the details of a management plan for the site (Turner 2015).
Other studies of the lead-mining landscape of the North Pennines include an initial archaeological survey of Knock smelt mill complex, situated on the south bank of Knock Ore Gill (C), approximately 20km to the south-west of Nenthead. A precise date for the construction of the smelt mill has not been determined, although it was almost certainly established by the sixth Earl of Thanet to smelt ore from his mines on Knock Fell in the early 18th century. The survey concluded that the earliest surviving remains pertain to the smelt mill and comprise the eastern three cells of the north range, with a waterwheel pit on the north side that linked to the bellows room in the centre of the building. The smelting rooms lay either side of the bellows, both of which were found to retain evidence for the smelting hearths. The remains of several ancillary buildings that appeared to have been added at a slightly later date were also recorded (Kempsey and Town 2014).
Several small-scale projects in the Lake District National Park have also enabled features associated with the extraction of lead and silver to be recorded. Elements of the Silver Gill mine near Caldbeck (C), for instance, have been investigated by the Mines of Lakeland Exploration Society (MoLES), which discovered a level above the well-known open coffin-level, whilst excavation revealed another hand-cut coffin level, cross-cut to the Silver Gill vein. Remarkably, several timber artefacts that survived in-situ were discovered, and may represent the remains of a tramway used by the Company of Mines Royal c 1586. The Lake District was also an important centre for the extraction of copper and bulk minerals, such as slate from quarries around Honister and Coniston, the latter dating to at least the 16th century.
A bulk mineral that was crucial to Post-Medieval development was limestone, an extractive industry that has left substantial remains, especially in Cumbria and northern Lancashire. It was required for both agricultural and building purposes, although large-scale lime production was held back for a variety of reasons during the Post-Medieval period, and the most extensive remains derive from an exponential expansion from a field kiln-based activity supplying local farms to a significant industry in the 19th century, a transformation that in some cases will have eradicated any physical evidence for earlier workings. Limestone quarrying and associated kilns have been the subject of recent research, which has considered their distribution and history along the Pennine fringe (Johnson 2013).
Brick was used increasingly as an alternative to stone as a building material during the Post-Medieval period, although the kilns that produced these bricks are poorly represented in the archaeological record for the North West. The remains of clamp kilns, using locally sourced clay adjacent to the building site where they were used, have been uncovered in several rural locations. A good example was found on the boundary of the boroughs of Salford and Wigan (GM) during the excavations for the West East Link Main in 2010, which uncovered four parallel firing tunnels, separated by stacks that were two bricks wide (Gregory 2013, 24). Similar remains were found during excavations near Oxford Road in central Manchester, providing very rare evidence for an urban clamp kiln, although this example may have dated from the 19th century (PCA forthcoming).