@article{oai:rekihaku.repo.nii.ac.jp:00000595,
 author = {阿久津, 久 and 片平, 雅俊 and Akutsu, Hisashi and Katahira, Masatoshi},
 journal = {国立歴史民俗博物館研究報告, Bulletin of the National Museum of Japanese History},
 month = {Mar},
 note = {application/pdf, 茨城県は６世紀前半頃になると霞ケ浦を中心にした地域と，県西，県北の地域にそれぞれの特色が現れる。霞ケ浦沿岸では，三昧塚古墳にみられるような箱式石棺を埋葬施設に使い始めてから，この地域は，箱式石棺が主流となり，後期前方後円墳，円墳に設置されている。このような系譜をもつ地域の中に，僅かであるが，前方後円墳では出島村風返稲荷山古墳，大師の唐櫃古墳（彩色壁画），三昧塚古墳に近く沖洲古墳群に入る大日塚古墳，円墳では桜川村前山古墳には横穴式石室が設けられており，この地域での特殊性を示している。
一方，県西北部から県北にかけては，前方後円墳，円墳とも横穴式石室が主流となり，箱式石棺は少なくこれに横穴墓が加わる。前方後円墳に箱式石棺が使用されているのは久慈川流域にある大子町仲山3号墳にみられるが，この古墳群は，むしろ那須地域の影響を受けたものと考えている。
トータル的に分けた２つの地域のうち，後者の地域と筑波には，方墳に横穴式石室をもち，一部に壁画が描かれるものが７世紀前半頃に共通して現れる。新治国内では関城町船玉古墳（彩色壁画），筑波国内ではつくば市佐渡ケ岩屋古墳，那珂国内では水戸市吉田古墳（線刻壁画）がある。これに加えて勝田市虎塚古墳の横穴式石室のように後年に改装して彩色したものや，高国の日立市かんぶり穴横穴墓（彩色壁画）のように特異な性格をもつものがある。
この頃，国府がおかれた石岡市の南，千代田村の境に流れる恋瀬川を中心に群集墳が形成される。古墳形状は円墳，変形小型前方後円墳などバリエーションがみられ，箱式石棺が主体となっている。また，佐渡ケ岩屋古墳のある平沢・山口地区には，円墳に横穴式石室と，箱形横穴式石室がみられ，この箱形横穴式石室は，新治村武者塚古墳，土浦市石倉山古墳の地下式箱形横穴式石室に共通するものである。この形状は千代田村粟田栗山群集墳にもみられる。
これらはいずれも７世紀後半にみられるもので，常陸国府が石岡の地におかれた素地をこの終末期の群集墳の中に求められるようである。, In the first half of the 6th century two areas in Ibaraki Prefecture came to show distinctive characteristics: one area being the region centering on Lake Kasumigaura, the other being the western and northern parts of the Prefecture. Near Lake Kasumigaura, box-type stone coffins, as seen at the Sanmaizuka Tumulus, were used for the first time in the burial mounds.
This type of stone coffin became the most common, being placed in both the later keyhol-shaped burial mounds (square at the head and rounded at the foot) and round burial mounds. In areas with this tradition, a few tumuli have distinctive tunneltype stone rooms; some are keyhole-shaped tumuli, including the Kazegaeshi-Inariyama Tumulus in Dejima Village, the Karabitsu Tumulus at Taishi (with colored wall painting), and the Dainichizuka Tumulus in the Okisu Tumuli Group, which is close to the Sanmaizuka Tumulus; as well as the round shaped Maeyama Tumulus in Sakuragawa Village.
On the other hand, in the region from the northern to western areas of the Prefecture, the adit-type stone room is the most common in both keyhole-shaped and round tumuli; but a small number of box-type coffins and some cave-type graves are also seen. A box-type stone coffin is found in the keyhole-shaped Nakayama Tumulus No. 3 in Taishi Town, on the upper reaches of the Kuji River; however, the tumuli group to which this belongs is considered to have been influenced by the Nasu Region.
Square burial mounds with adit-type stone rooms, and sometimes with mural paintings, appeared in both the latter classification given above and in the Tsukuba region in the first half of the 7th century. Examples include the Funadama Tumulus (with colored mural painting) in Sekishiro Town in the province of Niihari; the Sadogaiwaya Tumulus in Tsukuba City in the province of Tsukuba; and the Yoshida Tumulus (with line mural drawing) in Mito City in the province of Naka. In addition to the above, some have special characteristics, for example, the adit-type stone room of the Torazuka Tumulus in Katsuta City, which was remodelled and colored at a later date; and the Kanburiyana cave-type grave in Hitachi City, which is decorated with colored mural paintings.
At the same time, a group of tumuli was built along the Koise River which runs south of Ishioka City, capital of the province, on the border with Chiyoda Village. The shapes of tumuli were varied, from round to deformed small keyhole-shapes, and the box-type stone coffin was the most common. In the Hirasawa-Yamaguchi District, where the Sadogaiwaya Tumulus is located, tunnel-type stone rooms and box-shaped adit-type stone rooms are seen in round tumuli. This box-shaped adit-type stone room is common to the underground box-shaped adit-type stone room in the Mushazuka Tumulus in Niihari Village, and the Ishikurayama Tumulus in Tsuchiura City. This shape is also seen in the Awata-Kuriyama Group Tumuli in Chiyoda Village.
These all appeared in the second half of the 7th century. Evidence of the fact that the capital of the province of Hitachi was placed at Ishioka can be sought in these tumuli groups of the final Kofun Period.},
 pages = {423--468},
 title = {常陸の後期古墳の様相},
 volume = {44},
 year = {1992},
 yomi = {アクツ, ヒサシ and カタヒラ, マサトシ}
}