Formation and shortening deformation of a back-arc rift basin revealed by deep seismic profiling, central Japan
Formation and shortening deformation of a back-arc rift basin revealed by deep seismic profiling, central Japan
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DOI：
10.1016/j.tecto.2004.07.004
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发表时间：
2004-09
期刊：
影响因子：
2.9
通讯作者：
Hiroshi P. Sato;T. Iwasaki;S. Kawasaki;Y. Ikeda;N. Matsuta;T. Takeda;N. Hirata;T. Kawanaka
中科院分区：
文献类型：
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作者：
Hiroshi P. Sato;T. Iwasaki;S. Kawasaki;Y. Ikeda;N. Matsuta;T. Takeda;N. Hirata;T. Kawanaka
北方的大窝（NFM）盆地是中新世裂谷系统在日本海的开放的最后阶段产生的。它将日本的主要构造分为两个区域，即盆地东北部的北向地质构造和盆地西部的东西向构造。Itoigawa-Shizuoka Tectonic Line（ISTL）界定了北方大窝的西部，并形成了一个活动断层系统，显示了日本岛屿中最大的滑动速率（4-9 mm/年）之一。2002年在国际空间技术实验室北方进行了深地震反射和折射/广角反射剖面测量，以描绘地壳结构和活动断层系统的深部几何形状。地震图像的解释的基础上的模式反射，地表地质和速度来自折射分析。68公里长的地震剖面表明，中新世NFM盆地是由一个东倾的正断层形成的，该正断层具有一个浅的平坦段至6公里深和一个较深的斜坡，穿透至15公里深。这种低角度的正断层起源于一个相对较浅的脆性/韧性剥离在一个高的热制度存在于中新世。NFM盆地被厚（>6 km）的沉积物堆积所填充。新近纪晚期以来的缩短是沿着沿着NS至NE-SE走向的逆冲断层进行的，这些逆冲断层先前是为了适应伸展而在其上盘产生断层相关褶皱的。根据我们的平衡地质剖面，中新世伸展的总量约为。晚第三纪晚期至第四纪缩短总量约为42 km。23公里。
The northern Fossa Magna (NFM) basin is a Miocene rift system produced in the final stages of the opening of the Sea of Japan. It divides the major structure of Japan into two regions, with north-trending geological structures to the NE of the basin and EW trending structures to the west of the basin. The Itoigawa-Shizuoka Tectonic Line (ISTL) bounds the western part of the northern Fossa Magna and forms an active fault system that displays one of the largest slip rates (4–9 mm/year) in the Japanese islands. Deep seismic reflection and refraction/wide-angle reflection profiling were undertaken in 2002 across the northern part of ISTL in order to delineate structures in the crust, and the deep geometry of the active fault systems. The seismic images are interpreted based on the pattern of reflectors, the surface geology and velocities derived from refraction analysis. The 68-km-long seismic section suggests that the Miocene NFM basin was formed by an east dipping normal fault with a shallow flat segment to 6 km depth and a deeper ramp penetrating to 15 km depth. This low-angle normal fault originated as a comparatively shallow brittle/ductile detachment in a high thermal regime present in the Miocene. The NFM basin was filled by a thick (>6 km) accumulation of sediments. Shortening since the late Neogene is accommodated along NS to NE–SE trending thrust faults that previously accommodated extension and produce fault-related folds on their hanging wall. Based on our balanced geologic cross-section, the total amount of Miocene extension is ca. 42 km and the total amount of late Neogene to Quaternary shortening is ca. 23 km.