四川较场弧形构造与1933年叠溪地震发震构造的再讨论

较场弧形构造是四川众多弧形构造带之一。本文对该弧形构造的特征及其西冀发育的松平沟断裂的新活动性作了进一步论证，确认松平沟断裂属全新世活动断裂。该弧形构造西翼弧顶部位1933年曾发生过叠溪7．5级地城,丧人对该次地震的发震构造众说纷纭。作者通过近年来在现场的多次考察，并对该次地震的等烈度线形态，地表震害展布特征，建筑物沿松平沟断裂的左旋位错，震后持表发育的西北向地震地裂缝等现象的进一步研究认为，1933年叠溪7．5级地震的发展震构造仍为较场弧形构造西翼的松平沟断裂。

Re-discussion of the Seismogenic Structure of the Diexi Large Earth quake in 1933 and the Arc Tectonics on Jiaochang, Sichuan Province

The arc tectonics on Jiaochang is one of those in Sichuan Province.The features of the Jiaochang arc tectonics and the Quaternary activity of Songpinggou fault which exists on the western wing of the arc have been demonstrated further. And the Songpinggou fault is finally considered a Holocence one. It is the arc tectonic that had ever caused the Diexi earthquake with magnitude 7.5 in 1933 at the place where is on the western wing and near the top of the arc. About the seismogenic structure of the Diexi earthquake in 1933, there have been many opinions. The authors considered the seismogenic structure of the Diexi earthquake in 1933 is the Songpinggou fault, which is on the western wing of the Jiaochang arc tectonics, based on the further researches on the isoseismal formation, the distribution of the disaster caused by the earthquake, the sinistral offsets of the buildings along the Songpinggou fault and many ground ruptures striking NW after the authors had reviewed the seismological field several times in recent years.