Abstract

We show that volcanic activity was occurring in the NW Pacific seafloor areas adjacent to Japan, the Kuril Islands, Kamchatka, and the Commander Islands during Pliocene to Pleistocene time. The activity was highest in two areas. At least three major volcanoes originated and were active in the southern area behind the Japan trench off Honshu and Hokkaido. Lava-dominated Pleistocene stratovolcanoes originated and were active in the Detroit and Wayne volcanic massifs in the central area, on the Detroit rise, which is the northern termination of the Emperor Ridge. As well, there was a large (42 km across) volcano-tectonic structure that was previously unknown, viz., a deep-sea calderoida. Somewhat north where the margin of the Obruchev Rise is adjacent to the deep-sea Kamchatka trench, a volcano (?) was active during Pliocene time whose present-day summit is at a height of –713 m. We show that the Detroit Seamount rise is a seafloor block that was uplifted in the Pliocene in the form of a horst and showed Pliocene–Pleistocene volcanic activity.

中文翻译：

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西北太平洋的上新世—更新世深海火山

摘要

我们显示，在上新世至更新世时期，邻近日本，千岛群岛，堪察加半岛和指挥官群岛的西北太平洋海底地区正在发生火山活动。活动在两个领域中最高。在本州和北海道附近日本战behind之后的南部地区，至少有三座主要的火山起源并活跃。熔岩为主的更新世平流层火山起源于底特律上升带中部的底特律和韦恩火山地块，活跃于底特律，这是皇帝岭的北端。同样，还有一个大的（横跨42公里）火山构造结构，以前是未知的，即深海火山口。北部某个地方，奥布卢切夫（Obruchev）上升的边缘与深海堪察加半岛海沟相邻，在上新世时期，一座活火山（？）活跃，今天的山顶高度为–713 m。我们显示，底特律海山上升带是一海底块体，它以一种霍斯特的形式在上新世隆升，并显示出上新世至更新世的火山活动。