A typical grave field represents a mixture of smaller round tombs (MT-A, MT-B) and larger structures, and often we find two or more fields of different mound types next to each other, so in the example of the cemeteries of Shambu #0278.a-c, with another two yet not clearly identified fields situated further to the east (#0279.a-b). Such a situation indicates the principal chronology where in contrast to the smaller round tombs, a burial used throughout the tumulus period, the MT-C structures (at least the larger one) are to be identified as imperial era monuments. The situation of #0278.a-b, for example, may in fact reflect the history of a re-occupation of an older site or the establishment of a new field (#0278b) next to an older one, possibly of different lineage affiliation (#0278a).