Monument record MDR5800 - Iron furnaces and associated features, Stanley Grange, Dale Abbey

A programme of fieldwalking and geophysics in advance of proposed open-cast coal mining revealed a scatter of medieval (13th-14th century) pottery and iron working slag, including tap slag, to the north-east of Stanley Grange, associated with intense magnetic anomalies. A series of machine trenches revealed furnaces which were dated using archaeomagnetic techniques to the 13th or to the 15th century (1220-1280 AD, or 1400 - 1440 AD), both dates falling within the life of Dale Abbey, suggesting that the iron working was directly associated with the activity of the Abbey's grange at Stanley. A programme of more detailed excavation and recording was due to commence in summer 1997. (1) Detailed excavation revealed a variety of furnace types including draught induced forms associated with ore roasting and crushing. A significant part of the site will be excluded from opencast working. Furthermore, there is now evidence that the features thus far identified are only part of the whole site which extends into the field to the west of the driveway to Stanley Grange. (2) Scheduled. (3) An area excavation followed the completion of the evaluation and took place between June and August 1997. The most significant result was the excavation of eight medieval furnaces within an area associated with the preparation of iron ore, extraction of clay for furnace building and the disposal of iron slag. The furnaces exhibited a range of variations in form. None of the superstructures survived, neither was there any clear evidence surviving for associated buildings or other structures. Four archaeomagnetic dates were obtained, indicating that the furnaces were in use during the mid to late 13th century. One furnace was somewhat later and may have been used in the early 14th century. These dates are supported by the small group of 175 sherds of medieval pottery. A complete absence of 15th century material indicated that all activity had ceased before that time. Thirty-seven samples of tap-slag for seven furnaces and their associated slag pits were analysed. This established that two different smelting processes were in operation at Stanley Grange. The smallest furnace yielded slags of compositions consistent with traditional bloomery smelting, whereas the composition of the remainder indicated a more efficient and higher-temperature process. It was suggested that the furnaces relied on natural draught provided by the local prevailing wind. The most likely historical context for the site is a bloomery associated with the canons of Dale Abbey. The bloomery may have predated the formal foundation of the Abbey's grange at Stanley, which is not documented before 1291; however the development of iron working around Stanley might have provided one reason for the foundation of the grange. (4) Rescue excavation by Trent & Peak Archaeological Unit recorded the remains of part of an extensive medieval iron smelting site at Stanley Grange, Derbyshire. The pottery uncovered is significant as it adds a further stratified collection of medieval ceramics to the limited overall assemblage from Derbyshire. The notional dating framework for the pottery may be compared with that from archaeomagnetic dates gained from the iron-smelting furnaces. The abraded pottery from the site indicates activity generally during the 13th century and the evidence from the pits suggests that most activity ceased in the late 13th century. It is impossible based on the pottery alone that no activity continued into the early 14th century, but there is an absence of any diagnostic 15th century material. (5)