Positive research on the ancient tombs of the early times found at the southern end of the tomb range

为了揭示古墓分布南缘地区古墓的出现过程，对宫崎市青木1号古墓和斋藤市81号斋托巴鲁古墓进行了发掘研究。青木墓的规模为：长52m，圆形部分直径35~38m，高度4.5m，正方形部分长17m，高度1.7m~2m，正方形部分前部宽度约20m。在圆形部分发现了日本最大的木制墓室之一。在木制墓室中发现了小尺寸的掏空的木棺。此外，在墓葬的方形和平坦部分发现了部分出土的墓道(16米)。第81号斋托巴鲁古墓的比例与真木谷-伊西祖卡古墓的比例相同。圆形部分有两个台阶，墓穴周围的护城河在正方形部分的角落连接。凸起部分与墓葬圆形部分的背面相连，与陵墓圆形部分的底座部分同时建造。而投影部分的上部都被石头包围了。在凸出部分的表面、锁孔状堆墓的腰部和圆形部分的墓丘斜坡上发现了四个附属墓穴。可以推测，这座陵墓建于公元3世纪下半叶。研究结果如下：(1)九州南部公元3世纪出现锁孔墓葬；(2)九州南部锁孔墓葬形态和建造方式的多样性；(3)墓葬设施的多样性。

With the purpose of revealing the appearance process of ancient tombs in the southern peripheral areas of tomb distribution, the excavation research was given to the two ancient tombs : (1)Aoki ancient tombs No.1 in Miyazaki-city, and (2)Saitobaru ancient tombs No.81 in Saito-city. The scale of the Aoki tomb was as follows : the length : 52m, the diameter of the round portion : 35〜38m, the height of this portion : 4.5m, the length of the square portion : 17m, the height of this portion : 1.7m〜2m, the width of the front part of the square portion : about 20m. One of the largest wooden burial chamber, in Japan was found in the round portion. The small size hollowed-out wooden coffin was found in the wooden burial chamber. In addition a part of the excavated tomb passage (16m) was found in the square and flat part of the tomb. Saitobaru ancient tombs No.81 has the same proportion of that of Makimuku-isizuka mound. The round portion has two steps and the moats around the tomb joined at the corner of square portion. The projected part, which was connected with the back part of the round portion of the tomb, was built at the same time when the base part of the round portion of the tomb was built. And the upper part of the projected part was all surrounded by the stones. Four subsidiary tombs were found in the surface of the projected part, in the waist of a keyhole-shaped mounded tomb, and in the slope of burial mound of the round portion. It can be guessed that this tomb was built in the latter half of the 3^<rd> century. The following was the result of this research : (1)the keyhole tombs appeared in the 3^<rd> century in the southern Kyushu ; (2)the variety of the shapes and the building ways of the keyhole tombs ; and (3)the variety of the burial facilities.