论文部分内容阅读
为试图解释菲律宾群岛的大地构造,作者考查了该地区的地震和火山活动资料,确定了浅、中及深源地震的一些新断层面解。本文揭示出,在西菲律宾存在着一条向东下冲的带,它在内格罗斯岛附近发育颇佳。西菲律宾的几个浅源地震的断层面解,显示了具有向东或向北东滑动矢量的冲断作用。由于沿中吕宋西部附近的马尼拉海沟也发生着欧亚板块向东的剧烈俯冲,这表明从台湾到马鲁古海的苏扭威西岛,沿西菲律宾可能曾发生过欧亚板块的下冲作用。沿存在陆壳的一些地段,下冲则已停止。这一解释与本区地质和重力异常相符。在东菲律宾附近,菲律宾海板块向西的俯冲发生在:1)沿菲律宾海沟,2)沿靠近本哈姆隆起西缘的局部地带。因此菲律宾群岛东西两侧以活动而不连贯的俯冲体系为界。据推断,这些活动海沟系的某些段的一端附近有左旋走向滑动断层作用,表明运动属横移性质。菲律宾断层的地震活动集中在10°N和15°N之间的地带,看来是由于菲律宾海板块和欧亚板块相向运动而产生的应力在下冲过程中未释放所致。与菲律宾断层有关的浅源地震断层面解表明,左旋走向滑动与野外观测是一致的。本文研究表明,菲律宾断层地震活动的程度和震级组成了欧亚板块和菲律宾海板块之间运动的一个分量。
In an attempt to explain the tectonic setting of the Philippine archipelago, the authors examined seismic and volcanic activity data in the area and identified some new fault surface solutions for shallow, medium and deep earthquakes. This article reveals that there is an eastward red belt in the West Philippines that develops well near Negros Island. The fault surface solutions of several shallow earthquakes in the West Philippines show thrusting eastward or northbound. Since the drastic subduction eastward of the Eurasian plate also occurs along the Manila Trench near the western part of Central Luzon, this indicates that there may have been a blunder of the Eurasian plate along the western Philippines from Taiwan to the island of Suvarnabhumi in the Maluku Sea effect. Some parts of the continental crust exist, the undershoot has stopped. This interpretation is consistent with the geologic and gravity anomalies in this area. Near the Eastern Philippines, subduction westward of the Philippine Sea Plate occurs 1) along the Philippine Trench, and 2) along a localized area near the western edge of Ben Ham. Therefore, both sides of the Philippine archipelago activities and inconsistent dive system for the community. It is assumed that some sections of these active troughs have left-lateral strike-slip faults near one end, indicating that the movement is of a traversing nature. Seismic activities in the Philippine fault concentrated in the zone between 10 ° N and 15 ° N and appear to be due to the non-release of stress during undershooting as a result of the relative movement of the Philippine Sea and Eurasian plates. The shallow source seismic fault surface solution related to the Philippine fault shows that the left-lateral strike slip is consistent with the field observations. Our study shows that the magnitude and magnitude of the fault activity in the Philippines constitute a component of the movement between the Eurasian Plate and the Philippine Sea Plate.