The outcrop which illustrates the occurrence and horizontal extension of chalk-flint cycles on the Pacific seamount revealed as driling results of the Deep Sea Drilling Project (DSDP) has been found in the land area; in Chirai Quarry, northeastern part of Hokkaido. The Jurassic cyclic sequence of micritic limestone and nodular flints is of pelagic origin, as being recognized by geochemical characteristics. The cycle is unconformably overlain by volcanic debris which is also overlain by bedded red cherts. The stratigraphic sequence outcropped in the quarry can be correlated with the DSDP sequence on the summit of the Hess Rise, which shows the subsidence history of the summit below the calcite-compensation depth. The most important mechanism for the formation of the cycles of flint nodules in the micritic limestone, among others, can be interpreted to be dissolution cycles on seamount which could be caused by the cyclic, climbing movement of deep waters undersaturated in calcium carbonate below the calcite-compensation depth, as results of climatic catastrophes.

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In this paper, we clarify the process of promotion of dairy farming in Hokkaido and the penetration of dairy farming in municipalities and hamlets in the prewar period of the Showa era, focusing on the areas in Oshima Sub-Prefecture Office (mainly Yakumo town) and Abashiri Sub-Prefecture Office (mainly Abashiri town). In Hokkaido, Oshima Sub-Prefecture Office was an advanced dairy farming area, on the other hand , Abashiri Sub-Prefecture Office was an emerging dairy farming area apart from some exceptions such as Notsukeushi Town. In these areas, the driving forces of dairy business were the Hokkaido Office, Sub-Prefecture Offices, dairy capital (Rakuren, Hokkaido Rennyu Co., Ltd., Morinaga & Co., Ltd.), and farmers who organized cattle associations. In examining the development process of dairy farming, this paper focuses on the Second Colonization Plan of Hokkaido, the Five-Year Industrial Plan, and the Rural Revitalization Plan, especially the Five-Year Industrial Plan promoted by Sub-Prefecture Offices and the Rural Revitalization Plan promoted by Towns and Villages and hamlets. In the Second Colonization Plan of Hokkaido, the administrative organizations such as the Ministry of Home Affairs and the Ministry of Finance and the Hokkaido Office promoted dairy farming. In the Five-Year Industrial Plan, Sub-Prefecture Offices promoted dairy farming. In the Rural Revitalization Plan, from the head of Hokkaido Office to each farmer was the main promoter of the plan.

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