Mesolithic Sedentism on Oronsay: Chronological Evidence from Adjacent Islands in the Southern Hebrides
Mithen, Steven, Antiquity
The nature of Mesolithic subsistence and settlement on Oronsay (FIGURE 1) has been an issue of considerable debate. Mellars & Wilkinson (1987) argued that people could have been resident on that island all year round, an idea that was challenged by Mithen & Finlayson (1991) who suggested that the middens of Oronsay derived from many short-term visits by foragers principally based on the larger islands of Colonsay, Jura and Islay. Richards & Mellars (1998) presented data regarding the diet of humans represented in two of the middens, Cnoc Coig and Caisteal nan Gillean, the former of which had relied exclusively on marine protein and hence supported the notion of sedentism on Oronsay. In this contribution I will provide additional data of relevance to this issue in terms of new radiocarbon dates for Mesolithic sites on Colonsay and Islay. Calibrated values for dates cited in this text are provided at a 95.4% confidence level. These are derived from the OxCal computer programme (Ramsey 1995) employing the 1998 internationally recommended radiocarbon calibration dataset for the northern hemisphere (INTCAL98.14C: Stuiver et al. 1998).
[Figure 1 ILLUSTRATION OMITTED]
Placing Oronsay into a regional content
In the late 1980s debates about the role of the Oronsay middens within a Mesolithic settlement system were of limited value due to the rarity of well-dated Mesolithic sites on the adjacent islands to Oronsay: Jura, Colonsay and Islay. Mercer and Searight had discovered a suite of Mesolithic sites on Jura (Mercer 1968; 1970; 1971; 1972; 1974; 1980; Mercer & Searight 1986; Searight 1990; 1993). The absolute dates from these sites were either earlier than those from the Oronsay Middens, as at Lussa Wood (8195 [+ or -] 350 BP/8200-6300 cal BC, 7965 [+ or -] 200 BP/ 7500-6550 cal BC), or much later with Neolithic dates from Lussa River (4620 [+ or -] 140 BP/3650-2900 cal BC, 4200 [+ or -] 100 BP 3050-2450 cal BC) and Glenbatrick (4225 [+ or -] 230 BP/3600-2100 cal BC). The only dated Mesolithic site on Islay in the early 1990s was Newton, which was also substantially earlier than the Oronsay middens with dates of 7805 [+ or -] 90 BP/7050-6450 cal BC and 7765 [+ or -] 225 BP/7400-6100 cal BC (McCullagh 1991). With such few dates our ability to discuss the Oronsay middens in their regional context was limited. Consequently one of the rationales behind the Southern Hebrides Mesolithic Project (SHMP) was to locate and excavate further Mesolithic sites on Colonsay and Islay.
The fieldwork between 1988 and 1995 identified 22 locations on Islay and 3 on Colonsay where Mesolithic activity was implied by the nature of the chipped stone assemblages. A series of interim reports on specific aspects of the project have been published (Edwards & Mithen 1995; Finlayson & Mithen 1997; Finlayson et al. 1996; Lake et al. 1998; Mithen 1989; 1996; Mithen & Finlayson 1991; Mithen & Lake 1996; Mithen et al. 1992) and the final report of the project is in press (Mithen n.d.).
New radiocarbon dates
Thirty radiocarbon dates on wood charcoal were acquired from five Mesolithic sites: Bolsay Farm, Coulererach, Rockside and Gleann Mor on Islay, and Staosnaig on Colonsay (FIGURE 2). All but two of these (Staosnaig Q-3278, Bolsay Farm Q-3219) were derived by AMS on single entity samples. Of these dates, 14 came from Staosnaig and 10 from Bolsay Farm.
[Figure 2 ILLUSTRATION OMITTED]
The relatively large sets of dates from Staosnaig and Bolsay Farm were quite different from each other with regard to both context and range. Those from Staosnaig came from samples taken from within discrete features. All but three were pre-7000 BP--the exception being a Neolithic date (5415 [+ or -] 60 BP/4360-4040 cal BC) and two Bronze Age dates (3455 [+ or -] 60 BP/1440-1610 cal BC and 3395 [+ or -] 60 BP/1880-1520 cal BC) on charred plant material that appears to have been re-deposited into Mesolithic features. …