サクシュコトニ川遺跡 : 北海道大学構内で発掘された西暦9世紀代の原初的農耕集落

遺跡名：サクシュコトニ川遺跡, 所在地：北海道札幌市北区北17条西13丁目3番地（北海道大学札幌団地内）北緯43°04' 東経141° 20',調査主体：北海道大学, 調査機関：北海道大学埋蔵文化財調査室, 発掘期間：1981年（昭和56年） 8月14日～ 1982年（昭和57年） 9月24日, 調査面積：5,904㎡, 調査結果：上層より層位を異にして3文化層が確認された．『第1文化層』は擦文時代後期前半（西暦9世紀後半？）．焼土が1個所検出されたほかは遺物集中地点のみ．土師器（土師質土器）甕12個体，須恵器1個体が検出された．坏は検出されていない『第2文化層』は擦文時代中期前半（西暦9世紀中葉）．竪穴住居跡5軒・土壙6基・集石遺構7個所・炭化物マウンド1を含む焼土と炭化物集積139個所（73ブロック）が検出された．ここから，土師器坏113個体，土師器甕183個体，その他1個体および須恵器16個体・土製支脚7個体・土製羽口2個体・土製紡錘車14個・土製玉17個・黒曜石製剥片および石器77点・金属製品3点・骨製銛先1点，大型浅鉢1点が出土した．また，サケ科魚類を中心とする魚骨片， 栽培植物の種子（オオムギ・コムギ・キピ・アワ・シソ・アサ・アヅキ・ウリ・コメ）など，炭化材（ヤナギ属・トネリコ属・クルミ属・カエデ属・ニレ属）が検出された．集落跡の南部に接する埋没していた幅12mの旧河川から『魚類を捕獲するための柵列遺構』が木製銛，金属製魚鈎銛（マレク）などの漁具や用途不明の木製品をともなって発見されている．ただし，これが第1文化層・第2文化層のいずれに属するものなのかについては，確定できなかった．『第3文化層』は2次的な堆積層で，続縄文時代中期後半（西暦4世紀）とおもわれる土器片が検出されただけであった．資料の所在：発掘された資料は北海道大学内の埋蔵文化財調査室に展示・保管されている．Site Name: Sakushu-Kotoni-Gawa Site, Address: 3 Banchi Kita 17 Jo, Nishi 13 Chome Kita-ku Sapporo, Hokkaido, Longitude and Latitude: 43°04'N 141。20'E, Location: On the campus of Hokkaido University, Research Organization: Hokkaido University Salvage Archaeology Laboratory, Excavation Dates: August 14, 1981 to September 24, 1982, Excavation Area: 5,904㎡, Results: Three cultural levels (components) have been distinguished., First Level： The upper, or youngest, is early Late Satsumon and dates to the early tenth century. A probable hearth consisting of burned soil was found. The only other features was a few concentrations of artifacts. The pottery sherds are estimated to comprise 13 vessels., Second Level: This component is early Middle Satsumon (late Ezo・Haji) and dates to the middle ninth century. Five pit houses, a possible garbage pit, seven concentrations of river pebbles (7 to 64 stones each), a midden mound (tankabutsu maundo) containing concentrations of pottery, wood charcoal, other plant remains and burned soil were found. Concentrations of burned organic material were found at 139 locations. Artifacts in this component consist of pottery estimated to represent 313 vessels, 7 clay firing pedestals (Shikyaku) 2 bellows' nozzles, 14 clay spindle whor is, 17 clay beads, 77 obsidian flakes and tools, 3 pieces of metal (iron and tin), and one bone harpoon head. A large quantity of fish bones, mainly of the salmon family, were recovered. Carbonized wooden construction material was made from willow, esh, walnut, maple and beech. In addition, ten taxa of cultigens are present in flotation samples from this component. They consist of barley, wheat, broomcorn millet, foxtail millet, rice, Japanese red bean, mung bean, melon, beef steak plant, and hemp. Third Level: This is the oldest and deepest level at the site and is evidenced by only a few Epi-Jomon artifacts. Baried River Channel Excavation : To the south of the hamlet is a 12 meter wide abandoned river channel. A fish trap or weir was unearthed. An iron hook or barb was found in the weir. Other artifacts found in this area include a wooden fish spear, a wooden foreshaft, other fishing related tools, and several functionally ambiguous wooden tools. Unfortunately, whether the weir and artifacts are associated with the first or the second component has not been determined. Comments on Pottery and Artifact Distributions : Most of the pottery was manufactured on a potter’s wheel. Disposal patterns have been clarified through the examination of potsherd distributions. Potsherds were not randomly discarded; rather, they were disposed of in specific areas. Interestmgly, clay beads, a potsherd engraved with a written character, and various other kinds of artifacts are concentrated in the tankabutsu maundo (midden mound). This pattern of deposition is often observed among later Ainu villages. Plant Remains Summary : Nearly one quarter million carbonized cultlgen seeds and nearly 2000 specimens of wild weedy carbonized seeds and fruits have been identified in about 150 flotation samples from the Ezo・Hajicomponent. Approximetely one half of the nearly 400g. seed collection has been examined to date. Descriptive, taxonomic, and quantitative data are reported. About 46% of the non-cultigens are weedy annuals and 47 % are freshy fruit seeds. The so far identified and unknown taxa number 32, 26 of which have been identified. The plant remains collection is consistent with that of a food producing economy. Field weeds, forest edge taxa as well as cultigen by-products such as rachis fragments are all present. Of all of the cultigens present, wheat is the most unusual in that no precisely comparable type of wheat is known elsewhere. The grains are significantly smaller than other wheats but their overall shape and size most closely resembles Indian dwarf wheat. This points to a strong possiblity that East Asian wheat is derived from Central Asian rather than Middle Eastern populations of wheat. It may also imply that the same is true for other Western Asian cultigens found in Japan and China. Research on the collection is continuing in order to answer these and other questions