During the Initial Jomon period (about 11,500–7000 cal BP), coinciding with the onset of the Holocene, marine resource utilization appears to have increased as sedentism progressed in regions around Honshu Island. The Tenjinyama site, located at the tip of the Chita Peninsula, yielded a substantial quantity of pottery and faunal remains from stratified deposits attributed to the later phase of the Initial Jomon period. Although situated within a shell midden distribution zone, the site notably lacks a shell midden. Its unique location and absence of shell deposits provide an opportunity to examine characteristics of their hunting-gathering economy. Analysis of the faunal remains indicates a faunal exploitation strategy centered on hunting deer and wild boar, supplemented by spearfishing targeting surface-swimming fish such as mullet. The correlation between bone portion survivorship and bone mineral density for deer and boar suggests that partial meat may occasionally have been obtained from other groups. The site location likely offered access to diverse fishing grounds, supporting a fish-focused strategy with higher caloric efficiency than shellfish gathering. These insights imply that marine resources may have been exchanged with groups in the northern part of the peninsula for food and raw materials used in tool production. In addition, changes in material quantities by 10 cm sedimentary intervals suggest a possible decline in activity around the age of the K-Ah volcanic eruption, followed by recovery. The continuation of activity may have been supported by resilience based on marine resource use, facilitated by intergroup exchange networks.
Masato Hirose (Thu,) studied this question.