posted on 2015-11-19, 09:02authored byJ. H. (James Hendrik) Rieuwerts
The thesis traces the development of lead mining in Derbyshire, particularly the drainage, from Roman times. The ore deposits are principally contained within the Carboniferous Limestone and are heavily watered, so that as mining proceeded from about 1630, the orefield became pre-eminent for the construction of long drainage adits locally known as soughs. Examination of contemporary mining documents and printed sources, coupled with field evidence, both surface and underground, has demonstrated that both hard-rock excavation and ore extraction was dictated by the available technology rather than by geological consideration, though the easier excavation through shale was preferred where a potential advantage could be seen. No technical innovations can be traced specifically to the Derbyshire orefield. New ideas were sometimes adapted rapidly, but not comprehensively. The peculiar mining laws, together with a lack of concentrated capital investment, were largely responsible for local difficulties in taking up the new ideas. The lead miners' comprehension of the geology is examined. While a detailed local knowledge of the succession of strata is evident from about 1650, when veins were followed under the cover of shale, little evidence has been found to suggest any overall understanding of the stratigraphy of the whole orefield until the end of the 18th century. Otherwise veins were found by a combination of intuition and close observation. Drainage projects can be shown to be linked closely with the development of individual mining areas, and these together revealed the geology during the peak mining period of the mid-18th century. An appendix catalogues over 330 known or suspected soughs and includes brief notes on the history and geology of each.