Ruisasi 1 and the earliest evidence of mass-produced ceramics in Caution Bay (Port Moresby Region), Papua New Guinea

The history of pottery use along the south coast of Papua New Guinea spans from Lapita times, here dated to 2900–2600 cal BP, through to mass production of pottery associated with a number of ethnographically-known interaction (and exchange) networks. Understanding the antecedents and developmental histories of these interaction networks is of considerable importance to archaeological research from local to western Pacific geographical scales. The archaeological site of Ruisasi 1 located at Caution Bay near Port Moresby provides new insights into scales of pottery production before the development of the regional Motu hiri exchange system within the past 500 years. Here faunal remains indicate occupation by marine specialists who exploited a diverse range of local marine environments. Nearly 20,000 ceramic sherds are present in Square A, mostly from a 26 cm thick 'pottery midden'. A minimum of 45 red slip/plainware vessels based on conjoined sets of sherds plus two vessels with incised decoration are present; the maximum number of clay vessels based on Fabric Types is 146. The globular red slip/plainware pots have standardised shapes and sizes, consistent with mass pottery production. The concentration of sherds from these pots within the pottery midden reflects shortduration depositional events within the period of village life c. 1680–1180 cal BP. Whether or not the pots were made locally or imported is the subject of ongoing research. Whatever the case, Ruisasi 1 raises the possibility of mass pottery production linked to a regional interaction network pre-dating the hiri