Lead Isotope Analyses from Tell Abraq, United Arab Emirates: New Data regarding the 'Tin Problem' in Western Asia
Weeks, Lloyd, Antiquity
The subject of this article is the evidence for the earliest use and trade of tin and bronze(1) in Western Asia. The article begins with an outline of the 'tin problem', followed by an overview of recent archaeometric research programs of importance to discussions of the Early Bronze Age tin trade in Western Asia and the Aegean. Subsequently, relevant new lead isotope data from the site of Tell Abraq are presented, and the implications for the advent of bronze use in Western Asia are discussed.
Why is tin a problem?
Discussions of the tin trade in Bronze Age Western Asia rely primarily upon three forms of evidence: archaeological, geological and textual. Unfortunately, these categories of information have tended to suggest conflicting explanations with regard to aspects of the Bronze Age tin trade, giving rise to the 'problem' to which this article is addressed. Bronze Age tin sources remain unidentified after more than 50 years of archaeological investigation in Western Asia, with likely candidates sequentially nominated, debated and dismissed in an ongoing debate (e.g. Muhly 1973; 1985; 1993; Stech & Pigott 1986; Yener & Vandiver 1993; Moorey 1994: 297-301). The relevant data and hypotheses are summarized below.
Archaeological evidence for early bronzes
Bronzes, defined variously as copper alloys containing over one or two percent tin, first appear in a number of areas of Western Asia at the beginning of the 3rd millennium BC. In Mesopotamia, bronzes first appear in the Early Dynastic I (ED I) period at the Y cemetery at Kish, c. 2900-2700 BC (Muhly 1995: 1507; Muller-Karpe 1991), but remain uncommon until the ED III period (c. 2600-2400 BC), when they form a significant percentage of the copper-based objects found in the Royal Cemetery at Ur (Muller-Karpe 1991; Muhly 1985: 281).
Bronzes of a similar antiquity are also found further to the west. A cache of human figurines from Tell Judeidah in northern Syria which dates to approximately 3000 BC contains some of the earliest known examples of bronze, with other bronzes of similar date known from nearby sites (Stech & Pigott 1986: 52). Early or mid 3rd-millennium bronzes are also reported from southeastern Anatolia at Tarsus (Yener & Vandiver 1993; Muhly 1993: 240), and from central Anatolia at the sites of Ahlatlibel, Mahmatlar, Alaca Huyuk and Horoztepe (Esin 1969; Muhly 1993: 240-42).
Additionally, evidence of significant bronze use is found in 3rd-millennium contexts in northwestern Anatolia, at the sites of Troy and Beshiktepe (Pernicka et al. 1984; Muhly 1993: 241), and at a number of nearby settlements in the Aegean such as Poliochni on Lemnos (Pernicka et al. 1990), Thermi on Lesbos (Begemann et al. 1992; 1995; Stos-Gale 1992) and Kastri on Syros (Stos-Gale et al. 1984). These bronzes were thought to have been amongst the earliest in the Western Asia, dating to the first half of the 3rd millennium BC, but more recent debate has tended to date them towards the mid-third millennium (Coleman 1992: 276; Mellink 1992: 219; Muhly et al. 1991: 215ff.). From this period comes the earliest example of metallic tin in the region, a bangle from Level IV at Thermi (Begemann et al. 1992).
Elsewhere, tin is used very infrequently in 3rd-millennium Egypt and Palestine (Muhly 1993: 243, although admittedly few analyses of Egyptian material exist), and in Iran with any great frequency only at the site of Susa in the Susa D period, with isolated examples from Susa A, B and C contexts (Moorey 1982; Stech & Pigott 1986: 42-3; T.F. Potts 1994: 155). By the end of the 3rd millennium, however, the use of bronze becomes much more widespread, and the 2nd millennium sees the development of a true bronze metallurgy in most areas of ancient Western Asia.
Geological research on tin deposits in Western Asia
It has been suggested that the pattern of early bronze use in Mesopotamia, central Anatolia and the Troad might be explained by the existence of local tin deposits, which were exploited to meet local needs, in each of these areas (Renfrew 1967). …