オホーツク海および天北日本海側海域の地質構造と堆積盆について

抄録

In the Sea of Okhotsk off the northern Hokkaido island, two sedimentary basins and two basement plateaus are present. The former are the Esashi-Monbetsu Oki basin and the Abashiri-Kitami Yamato-tai basin, and the latter are the Monbetsu Oki basement plateau and the Okhotsk basement plateau.
The Tenpoku sedimentary basin extends over the northwestern Hokkaido nearly to the Rebun island. The author concludes that foldings on the eastern flank of the basin is controled by several lines of thrust fault system almost parallel to the eastern mountainous terrains and also ascribed to diapirism or flow of the middle Miocene shale (Masuporo formation). These faulting system is estimated to be derived from upheaval of the eastern margin of the basin during Neogene time.