Experimental archaeometallurgy

Experimental archaeometallurgy is a subset of experimental archaeology that specifically involves past metallurgical processes most commonly involving the replication of copper and iron objects as well as testing the methodology behind the production of ancient metals and metal objects. Metals and elements used primarily as alloying materials, such as tin, lead, and arsenic, are also a part of experimental research. Experimental archaeometallurgy is a subset of experimental archaeology that specifically involves past metallurgical processes most commonly involving the replication of copper and iron objects as well as testing the methodology behind the production of ancient metals and metal objects. Metals and elements used primarily as alloying materials, such as tin, lead, and arsenic, are also a part of experimental research. The theory behind experimental archaeology comes from the new archaeology technique of the 1950s to use modern day examples in the form of experiments and ethnologies as analogues to past processes. Experimental archaeometallurgy is considered a part of general experimental archaeology and is rarely separated in the literature and as such, many of the principles stay the same while there is a greater focus on a single subject. Archaeometallurgy works as a good field for experimental reproduction because of the evidence that is provided from excavation is a good starting point for reconstruction. Metallurgical remains provide a durable product that has relatively durable evidence of production methods such as slag and refractory ceramic remains. Experimentation comes in a varied amount of forms including object replication, system replication, behavioral replication, and process replication. Archaeometallurgical experimentation typically takes place in controlled laboratories or tries to remain as authentic as possible by being conducted using only the materials and facilities that were available to the subjects whose technology is trying to be reconstructed. Regardless of location though, the experimentation is always conducted under a different mindset outside the context of what was originally intended. A constant problem in any type of experimental archaeology is the cultural distance between the archaeologist and the individual who originally was involved with the metallurgy. This difference in mindset may lead to misunderstandings in the processes behind the metallurgy. Second to this, not all experiments are successful and it is hard to determine if this is the fault of the techniques used or the individual conducting the experiment. Ethnoarchaeology has been widely used in conjunction with experimental archaeology using the techniques of modern peoples as analogues to the processes of the past. The attempted use of ethnology in archaeology tries to counteract the cultural distance of the researcher from process by changing the context of experimentation. Africa has played a large role in reconstructing copper smelting and bloomery iron furnaces as there are still several places that practice a workshop production of iron. Killick has been one such archaeologist to utilize surviving iron production in Africa to gain further insight into how other furnaces from around the world may have been constructed. Mining is among the first steps of producing metal and as such is one of the foci of experimental archaeometallurgy. However, experimental research on mining is mostly limited to firesetting and the reproduction and use of mining tools. Firesetting is the process of exposing a rock face to high temperatures to induce cracking, spalling, and an overall increase to the brittleness of the rock in order to make it more susceptible to mining processes. Understanding the process of firesetting has been a crucial element to the development of an archaeological history of mining and as such has been the subject of several experiments to reproduce the technique. Typically firesetting experiments are conducted by setting a fire next to a predetermined rock face while taking measurements on the amount of and type of fuel used, temperatures of the fire and rock face, the amount of spalling before and after excavation, as well as the amount of time required for the different procedures. This examination allows for several possible inferences to be made about the mining process including the total amount of fuel a mining site may have needed to complete and its effects on the surrounding environment as well as how mining labor could have been organized. One outcome of firesetting experimentation is the realization that the quenching, or dousing the rock face with water after heating, is not necessary to making the rock face easier to excavate. The quenching process had been a standard step in most experiments with firesetting, but now more research is necessary to answer the new question of why quenching was used if it was not effective. Experimental reconstruction of tools used in prehistoric mining is often written about in conjunction with the tools use after the process of firesetting. The experimental mining tool assemblage are primarily made up of hammerstones and antler picks that are reconstructed using willow and hazel sticks, rawhide, and hemp string to implement various hafting techniques and methods of utilization. Smelting or the reduction of an ore to its metallic state is the primary source of experimentation in archaeometallurgy. In its simplest form smelting can be accomplished by placing an ore sample between two pieces of combusting charcoal in an oxygen reducing atmosphere with a compressed air source to feed the combustion and result in temperatures high enough to smelt metal. But to reach this final metallic state several things need to be done first including the processing of the ore to remove waste or gangue material, the possible roasting of the ore, the smelting of the ore, and then there is the possibility of refining the metal through a series of remelts. Then, through chemical or microscopic analysis, the products of the smelt are analyzed and compared with the findings of archaeological excavation in order to examine the likelihood of various manufacturing processes.