近畿における遠賀川系甕の成立過程 : 摂津・河内・大和の弥生甕

本稿は摂津・河内・大和など近畿中央部において弥生甕が成立する過程を明らかにしたものである。弥生甕とは弥生Ⅰ期の西日本各地に新たに出現する甕を指し，これまで主に板付式，遠賀川式，遠賀川系の甕とよばれてきたものである。私は先に，九州北部から中部瀬戸内にかけての弥生甕を検討して，弥生甕には系統を異にする三つの流れがあることを明らかにした。一つは早期の突帯文甕を母胎とする突帯文系甕が弥生甕となるもので，筑後の亀ノ甲タイプや豊後の下城式などが該当する。二つ目は，一つ目と突帯文甕を母胎とする点は同じだが，突帯文系ではなく外反口縁甕を目指す動きである。西部瀬戸内の口縁下端凸状甕が典型的な例である。三つ目は中期無文土器の系譜を引く板付祖型甕を母胎に，板付Ⅰ式甕，遠賀川式甕へと向かう流れである。1980年代の半ばまで弥生Ⅰ期の甕といえば，三つ目の甕を意味していた。はじめの二つは分布域が狭く，地域ごとに特徴的なあり方を示すことから「地域甕」，三つ目は広範囲に分布し，地域差も少ないことから「標準甕」と命名した。この視点にたって近畿中心部の弥生甕について検証したのが本稿である。分析の結果，次のことがわかった。一つは遺跡ごとに成立する弥生甕の種類は異なること。二つ目はこれらの遺跡では，まず突帯文系と外反口縁甕をもつ地域甕が成立した後，限られた遺跡のなかで標準甕が成立するために，標準甕は時期的にも地域的にも分布が限られることを確認したことである。以上のことから，近畿の遠賀川系甕はまず屈曲型一条甕が外反口縁甕へと変容したあと，中段階になって遠賀川系甕として定型化すると理解した。地域甕から標準甕が出てくるのである。当初から標準甕が成立し，その影響で外反口縁甕が成立する中部瀬戸内以西の地域との大きな違いである。This paper will explain the process by which Yayoi jars emerged in places such as Settsu, Kawachi and Yamato in central Kinki. Yayoi jars are new jars that appeared in the Early Yayoi period in various areas of western Japan. Up until now they have mainly been referred to as Itazuke-type, Onga River-type and Onga River-style jars. In an earlier examination of Yayoi jars from northern Kyushu through to central Setouchi, I have shown that there are three different varieties of Yayoi jars. The first has come from the cord-patterned jars of an earlier period whereby cord-patterned(tottaimon) jars became Yayoi jars, with jars of the Kamenoko type from Chikugo and the Shimojyo type from Bungo falling under this category. The second variety is similar to the first in that it comes from the cord-patterned jar, but shows a shift away from a cord pattern to a jar with a twisted rim(gaihan-koen), with jars from western Setouchi with raised undersides of the rim(koenkatan-totsujokame) being one such example. The third variety comes from the line of Itazuke jars that go back to the unpatterned pottery of the Middle period, and evolve into Itazuke I-type jars and Onga River-type jars. Until the middle of the 1980s, jars from Early Yayoi marked the last of these jars. The first two were called “regional jars” because they were distributed over a small area and showed influences particular to each region, while the third was referred to as the “standard jar” because these jars were distributed over a wide area and there was little variation according to region. This paper verifies Yayoi jars from central Kinki on the basis of these criteria. The results of this analysis are as follows. First, the Yayoi jars from each of the ruins are different. Second, it has been possible to confirm that because following the emergence of regional jars that were either the cord-patterned type or jars with twisted rims, standard jars emerged from a limited number of ruins, the Yayoi jars from each of these ruins are confined in terms of period as well as region.From the above, it follows that after curved single-ribboned(kukkyokugata-ichijo) jars evolved into jars with twisted rims, they came to be stylized as Onga River-style jars. This constitutes the emergence of standard jars from regional jars. This is vastly different from regions west of central Setouchi where standard jars came into existence first, which then led to the evolution of twisted rim jars