太平洋縁邊地域の亞濠大陸と南日本海 (1)

抄録

The true structural boundary of the Pacific margin should obviously have a border of considerable width surrounding it, yet all influencing the basin itself, which in turn must react upon it. For instance, the Austro-asiatic continental block is the true margin of the Pacific basin. This paper deals with the geologic characteristics of the Japanese archipelagoes and the southern islands, facing the ocean depths ; and the andesite line which curves strongly to the west toward the Halmahera Is.
The simatic of the Pacific bottom should have moved between New Guinea and the Palau-Marianen Is. forming an asymmetric echelon structure, the portion of which is alluded to the Halmahera Is. It is on this frame that geologic layers of New Guinea are extending far through Halmahera under the Philippine sea and Palau Is. group For instance the crystalline schist of Japan Is. of New Guinea is connected with those of Japanese Is. of the Palau group.
On the other hand, the outer zone of Japanese Is. which consists of crystalline schist, Mikabu, Chichibu and Akigawa series, forms monocline dipping north. On the whole, it is alluded to form an inclined syncline along the Median line, the south wing of which is postulated to extend for under the South Japan Sea. The southern limit of the South Japan Sea may be Karenko (Formosa) Sulpher Is. fault line, which corresponds to the north latitude 24, and to the Neo-Wallace Hosokawa line biographically. The submergence of the South Japan Sea may have occurred due to the depression of the outer zone which was thrust by the pushing out of the Loochoo arc from the northwest