Metal Detection. This project is to allow for the use of PI and ZVT metal detectors to survey approximately two acres of the “Gap”, a saddle-like landform within the original 150-acre survey. The primary goal of this project is to collect archeological information that will meet not only the needs of professional archeological community but also educate the public regarding the Northern Plains Indian War in general and the 1876 military campaign in particular, of which the Rosebud and Little Bighorn battles are associated. The intent of the metal detection is to determine if metal objects, specifically bullets are buried deeper than conventional (VLF or very low frequency) metal detectors can reach. The “Gap” area was covered in detail during the May 2015 field inventory effort, but little was found due to the heavy grass matte and previously agriculturally modified soils. VLF machines can reach a depth of 25 to 35 cm. The grass matte prevented detectors from placing the coil on the ground surface causing the loss of at least 10 cm of coverage depth. PI and ZVT machines can reach depths up to 1 meter thus ensuring that deeply buried metal items, such as bullets can be found. Survey of the approximately two acre area will involve the use of PI and ZVT metal detectors operated by experienced professional archeologists. The metal detecting technique will entail placement of a series of parallel and evenly spaced transects, each transect measuring no more than 5 meters wide. Optional secondary transects, with a perpendicular orientation may be employed as well, as a crosscheck against possible bias introduced by consistent sampling in only one direction. Upon receiving a positive signal, a metal detector operator will place a pin flag at that location and continue surveying. A metal detector and excavator team(s) will excavate selected targets. Excavation of a targeted artifact typically requires excavation of a hole that is approximately 30 to 50 cm in diameter. Excavation will involve using a conventional-sized shovel and trowel to ensure careful exposure of an in situ artifact and cleaning the walls of the hole. The intent is to limit ground disturbance sufficient to expose and recover the targeted artifact. Another team member will record each flagged location using a decimeter accurate GPS unit to provide the required (sub-meter) level of location fidelity. Excavation will cease immediately if inadvertent discovery of human remains should occur and all policy and regulato...
Metal Detection. Where there is a metal detector on a production line we must ensure that all products pass through the correctly functioning metal detector. This is so that any metal from a raw material or machine is detected and does not become a hazard to a customer. Other Critical control points are listed in the product specification for each product. Please follow the procedure regarding Critical control points carefully and ask your Supervisor, Trainer, Operator or QA if you are unsure of any items.
