Rākī

Concentration of Early Iron Age, Early Islamic, and Mid-Late Islamic settlements and primary copper production sites located on the western piedmont of northeastern Oman. The sites represent one of the densest and largest concentrations of industrial activity in southeast Arabia.

The Rākī sites of northeastern Oman are composed of significant concentrations of copper mining, smelting, and settlement activity principally dating to the Early Iron Age and Early Islamic Period. The sites include Raki 1, Raki 2, Tāwī Rākī, and Qurūn al-Khabab. They are located within the Wādī al-Rākī drainage ca. 10km northeast of modern Yānqūl, al-Dhāhirah governate (Fig. 1). Wādī al-Rākī is also variously known in the geological literature and maps as Wādī Rakah or Raqa (Belgrano et al. 2019). The wadi forms around and erodes the edges of significant exposures of upper and lower extrusives of the volcanic sequence of the Semail ophiolite, including exposures of copper-bearing basaltic pillow lavas. There are at least three volcanic massive sulphide deposits in this zone, including from northeast to southeast, al-Bishara, Hayl al-Safil, Rākī, and Tāwī Rākī (also modern al-Bukhaira). Of these, modern open cast mining operations extracted copper and gold from the weathered gossan caps of the al-Bishara and Rākī sulfide bodies in 1994-2005.

Archaeological significance of the Rākī sites was first recorded by Prospection (Oman) Limited in the early 1970s (Prospect Nos. 29-30) and the USGS (Coleman and Bailey 1981). They were subsequently discussed by Goettler et al. (1976) and Berthould et al. (1978). G. Weisgerber conducted two seasons (1995-96) of survey and excavations in Wādī al-Rākī, focusing efforts at the Early Iron Age settlement and slag heaps at Rākī 2 (Weisgerber and Yule 1999: 108-115). The Archaeological Water Histories of Oman Project renewed intensive investigations of the Rākī sites starting in 2019 (Sivitskis et al. 2019).

The greatest amount of activity at the sites date to the Early Iron Age and Early Islamic Period. Early Iron Age activity is largely limited to Rākī 2 (ca. 12 ha), which includes evidence for mining, copper sulfide smelting, and associated settlement. Radiocarbon determinations place this activity between 1200-800 cal BC. Slag heaps are composed of crushed and fragmented tap and furnace slags and significant quantities of ceramic furnace lining. The deepest accumulations of slag (ca. 6.5m) occur at the western edge of the site (Fig. 2), and in total amount up to ca. 45,000 tons.

Primary copper production activities dated to the Early Islamic Period are concentrated at Rākī 1 (ca. 20 ha) and Tāwī Rākī (ca 30 ha). Similar to other contemporary production sites in Oman (ex. al-ʿĀrjaʾ and Lasail), these sites are defined by several series of roasting installations, discrete slag heaps, associated reusable smelting furnace features, and permanent architecture. Evidence of multiple mining strategies, including underground and surface mining, is known in both locations, with shaft depths of up 34.4m below the modern surface. Well-preserved remains are consistent with an industrial scaled multi-stage copper sulfide production sequence (Fig. 3). Later Mid to Late Islamic activity is primarily represented by extensive pitting of slag heaps and pot shaped slags, which possibly derive from reprocessing of earlier slags. Estimations of slag weights vary, with up to 45,000 tons of slag at Rākī 1 and 100,000 tons at Tāwī Rākī. Extensive evidence for underground mining is well represented at Qurūn al-Khabab, and its periodization is likely attributed to the Early Islamic Period.

Joseph W. Lehner

References and suggested reading

• Belgrano, T.M., L.W. Diamond, Y. Vogt, A.R. Biedermann, S.A. Gilgen & K. Al-Tobi 2019. A revised map of volcanic units in the Oman ophiolite: insights into the architecture of an oceanic proto-arc volcanic sequence. Solid Earth 10: 1181–1217.
• Berthoud, T., R. Besenval, S. Cleuziou & N. Drin 1978. Les anciennes mines de cuivre du Sultanat d'Oman – Rapport préliminaire – Prospection 1978. Paris.
• Coleman, R.G. & E.H. Bailey 1981. Mineral deposits and geology of northern Oman as of 1974. USGS Open-File Report 81–452.
• Goettler, G.W., N. Firth & C.C. Huston 1976. A Preliminary Discussion of Ancient Mining in the Sultanate of Oman. JOS 2: 43–56.
• Sivitskis, A.J., J.W. Lehner, M.J. Harrower, I.A. Dumitru, P.E. Paulsen, S. Nathan, D.R. Viete, S. Al-Jabri, B. Helwing, F. Wiig, D. Moraetis & B. Pracejus 2019. Detecting and Mapping Slag Heaps at Ancient Copper Production Sites in Oman. Remote Sensing 11: 3014.
• Weisgerber, G. & P. Yule 1999. Preliminary Report of the 1996 Season of Excavation in the Sultanate of Oman, in P. Yule (ed.) Studies in the Archaeology of the Sultanate of Oman: 97–117. Rahden: Verlag Marie Leidorf.

_{Alternate spellings: Râkî, Raki}