K–Ar ages of the Akan‐Shiretoko volcanic chain lying oblique to the Kurile trench: Implications for tectonic control of volcanism
K–Ar ages of the Akan‐Shiretoko volcanic chain lying oblique to the Kurile trench: Implications for tectonic control of volcanism
复制标题
与千岛海沟倾斜的阿坎-希雷托科火山链的 K-Ar 年龄：对火山活动的构造控制的影响
DOI：
10.1046/j.1440-1738.2000.00273.x
复制
发表时间：
2000
期刊：
影响因子：
1.5
通讯作者：
T. Itaya
中科院分区：
文献类型：
--
作者：
Y. Goto;Atsushi Funayama;Nobuo Gouchi;T. Itaya
Akan-Shiretoko火山链位于千岛群岛西南弧，主要由九个陆上安山岩成层火山和三个破火山口组成。该岛链向西南-东北方向延伸200公里，与千岛海沟呈25度角倾斜。37个新的K-Ar年龄，加上以前的数据，表明沿着Akan-Shiretoko火山链的火山活动沿着Akan-Shiretoko火山链开始于大约4 Ma的Akan，在链的西南端，并系统地向东北方向发展，导致西南-东北走向的火山链。火山的这种时空分布可以通过从Akan地区向东北方向推进的背斜发展来解释，伴随着岩浆通过沿着背斜轴发展的东北向断裂上升。背斜向东北方向的发展导致了Akan-Shiretoko地区的隆起，并将该地区从海底变成了陆上。背斜的形成可能是由于南千岛群岛弧的变形，南千岛群岛弧前长条的西南迁移是由太平洋板块的斜向俯冲造成的。知床、国后、择捉岛和宇鲁普的梯形地形排列形成于约1 Ma。
The Akan‐Shiretoko volcanic chain, situated in the Southwestern Kurile arc, consists mainly of nine subaerial andesitic stratovolcanoes and three calderas. The chain extends in a SW–NE direction for 200 km, situated oblique to the Kurile trench at an angle of 25 degrees. Thirty‐seven new K–Ar ages, plus previous data, suggest that volcanic activity along the Akan‐Shiretoko volcanic chain began at ca 4 Ma at Akan, at the southwestern end of the chain, and systematically progressed northeastward, resulting in the southwest‐northeast‐trending volcanic chain. This spatial and temporal distribution of volcanoes can be explained by anticline development advancing northeastward from the Akan area, accompanied by magma rising through northeast‐trending fractures that developed along the anticlinal axis. The northeastward development of the anticline caused uplifting of the Akan‐Shiretoko area and changed the area from submarine to subaerial conditions. Anticline formation was likely due to deformation of the southwestern Kurile arc, with southwestward migration of the Kurile forearc sliver caused by oblique subduction of the Pacific plate. The echelon topographic arrangement of the Shiretoko, Kunashiri, Etorofu and Urup was formed at ca 1 Ma.