Archaeometallurgy and the University of Pennsylvania

Introduction

By: Vincent C. Pigott

Originally Published in 1982

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In December 1982, the Archaeological Institute of America holds its annual meet­ing, in Philadelphia. Of the various scholarly issues to be discussed, a tech­nological theme will receive particular emphasis: the role of metallurgy in ancient cultures. For the past several years scholars from a variety of disciplines at the Univer­sity of Pennsylvania have directed their research towards this topic. The contribu­tions in this issue of Expedition were pre­pared by some of these scholars whose disciplinary specialities include Anthro­pology, Near Eastern, Classical and His­torical Archaeology, Ancient History and Metallurgy. Depicted on the cover of this issue are images which reflect the blend of disciplines which characterize archaeo­metallurgical research: the analysis of technologically derived materials and the study of the cultural contexts of those who make use of the technology. It is the inter­disciplinary nature of archaeometallurgical inquiry which furnishes the breadth of analytical and technological approaches evident in these articles and characteristic of much of the recent work in this field.

Current studies are frequently directed towards understanding the nature and sig­nificance of the development of metal technology within its cultural context. This broad focus is made possible in part by significant advances in the science of metallurgy, whose developed tools and improved understanding have facilitated metallographic and elemental analysis of artifacts, providing important clues to the degree of technological sophistication exer­cised by ancient metalworkers.

The background image on the cover of this issue shows a scanning electron micro­scope (SEM) photomicrograph, at 3000 magnifications, of an early iron artifact (12th-11th centuries B.C.) from the Near East: a bracelet of true steel excavated by P. E. McGovern in a burial cave in the Baq’ah Valley, Jordan. The SEM permits the detailed investigation of the crystalline microstructure of metals as well as of non-metallic inclusions (slag) which ancient metals often contain. When utilized in con­junction with semi-quantitative, analytical, energy dispersive x-ray devices, the SEM is an even more powerful tool to the metal­lurgist who is investigating the composition of an artifact. Such devices permit elemental analyses at the microstructural level. For example, the much more precise information gained about the alloying ingredients used to produce a metal pro­vides important clues concerning the ability of ancient smiths to control the outcome of pyrotechnological processes.

Another significant new device providing specific quantitative information on the elemental composition of an artifact is proton induced x-ray emission (PIXE). It is currently being utilized in the study of ancient metals by Dr. Stuart Fleming, direc­tor of the University Museum’s Applied Science Center for Archaeology (MASCA), in collaboration with Dr. Charles P. Swann of the Bartol Research Foundation at the University of Delaware. One of the most significant advances of this and other new techniques is that the damage to the metal artifact being studied is much less than with the traditional techniques of emission spectroscopy and atomic absorption.

Another newly developed technique of interest in archaeometallurgy is lead isotope analysis. This process yields the proportion of isotopes of lead in a metal artifact or ore, a ratio which remains unchanged by smelt­ing or corrosion. The isotopic ratio detected in the metal artifact is directly comparable to that present in the original ore from which the artifact under analysis was smelted. Lead and silver ores, fortunately, all differ according to their own isotopic ‘fingerprint.’ Thus this technique is the most promising analytical tool yet available by which metal artifacts bearing similar iso­topic ‘fingerprints’ may be clustered, and by which lead-bearing metal artifacts may be traced to their original ore source.

At MASCA, Stuart Fleming is cur­rently involved in the application of this technique to ancient Egyptian copper arti­facts with detectable lead content. He is working in association with Noel Gale and Zofia Stos-Gale at Oxford, whose studies of Eastern Mediterranean lead and silver arti­facts and ores have shown this technique to

be very successful for both clustering and identifying proveniences of these materials. This investigation, plus a number of archaeometallurgical problems of current interest, is discussed in a special issue of the University Museum’s MASCA Journal (Vol. 2, no. 2). The articles included in this issue of Expedition, on the other hand, are of a more general nature and reflect wider issues in the study of archaeometallurgy: each article treats in some fashion an aspect of metallurgical innovation, innovations which account for major technological transitions of crucial sociocultural signifi­cance to the communities involved.

In the first article, Lee Horne discusses production of the ancient metalworker’s fuel, namely charcoal. Lee, whose training is in archaeology and ethnography, has con­ducted extensive ethnoarchaeological field work in north-central Iran. Her contribu­tion evaluates the social and ecological implications of charcoal production, partic­ularly the significance of deforestation to both ancient and modern populations.

The adoption of bronze in the ancient world is an innovation which has long been a focus of archaeometallurgical research, particularly by the University of Pennsyl­vania’s research team of Tamara Stech, Robert Maddin, and James D. Muhly. Bronze is an alloy of copper and tin and, despite the great popularity of this metal during the Bronze Age, tin does not appear to have been readily available in many of the areas where it was used, most notably in Southwest Asia, so argument has raged for many years about the source(s) of the tin used in that area in antiquity. Included in this issue of Expedition is an account of major tin fields recently identified in Afghanistan which could have been ex­ploited during the Bronze Age and later by peoples in Southwest Asia. The documenta­tion of these fields for the archaeological community is largely the accomplishment of Thierry Berthoud, a physicist, and Serge Cleuziou, a Near Eastern archaeologist, presently associated, respectively, with the French atomic energy commission (CEA) and the Centre National de la Recherche Scientifique (CNRS) in France.

Following the discussion of Bronze Age issues comes a brief discussion of the development of metallurgical technology (in this instance that of iron) as a con­tinuum of change fueled by the dual pro­cesses of innovation and adoption. An evaluation of the nature and significance of these processes within socio-cultural/tech­nological contexts has been espoused by such scholars as the cultural anthropologist

A. F. C. Wallace, the metallurgist C. S. Smith, and archaeologist/anthropologist R. McC. Adams. This article evaluates the appearance of early iron during the Iron Age of the Near East and concludes that while knowledge of iron and the ability to pro­duce it intentionally existed several cen­turies before its widespread adoption, it was only after certain major socio-political changes had occurred that iron production on a large scale became feasible and desirable.

Although the sequences of changes which a developing technology may have trav­ersed can often be deduced hypothetically, these transitions are often difficult to docu­ment archaeologically. A particularly satis­fying example of documented innovation has been identified at the Etruscan site of Poggio Civitate through the combined re­search efforts of Classical archaeologist G. Warden, Near Eastern archaeologist T. Stech, ancient historian/archaeologist J. D. Muhly, and metallurgist R. Maddin. This evidence, described in the fourth article, is significant in that it documents the probable early smelting of iron from iron-rich cop­per slag, a by-product of the copper smelt­ing processes. This technique was long thought possible but until now never identi­fied in the archaeological record.

The development of iron working can be seen as a series of technological innova­tions over numerous centuries, and in the final article Helen Schenck discusses the archaeological evidence for the rise of iron making in the eastern United States, a part of this process. Her contribution presents a brief historical overview of iron making from the Colonial period to the 19th cen­tury, outlines 19th century advances in technology, and stresses the archaeological evidence from which our current under­standing of this technological phenomenon in the United States has developed.

While this issue of Expedition deals pri­marily with archaeological evidence for the development of ancient metallurgy within its cultural context, the contribution of Lee Home illustrates the relevance of modern ethnographic data. In a similar vein, the Winter issue of Expedition will include an article by University of Pennsylvania scholars Sandra Barnes (Anthropologist) and Paula Ben-Amos (Art Historian) on the West African cult of Ogun, the god of iron, a cult known as early as the 18th century and which has a modern counterpart in the Caribbean. This article illustrates the funda­mental interconnection between technol­ogy and culture.

It is hoped that studies such as those de­scribed above will continue to expand the scope of our understanding of technological development as a phenomenon of complex social, cultural and environmental significance.

Cite This Article

Pigott, Vincent C.. "Archaeometallurgy and the University of Pennsylvania." Expedition Magazine 25, no. 1 (October, 1982): -. Accessed February 25, 2024. https://www.penn.museum/sites/expedition/archaeometallurgy-and-the-university-of-pennsylvania/


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