民乐盆地某些活断层断层泥中石英颗粒的表面特征及其地震地质意义

本文对民乐盆地三条活动断层断层泥内石英颗粒表面的显微构造作了较系统的研究。根据这些石英颗粒表面特征对该区莺落峡等断层的滑动性质和断层活动的相对年代进行了讨论。提出了以下的新看法:莺落峡断层的中段为粘滑段,东西两段为蠕滑段,古震源在该断层的黑河口一带,发生的时代大致在晚更新世晚期或全新世早期;茨湖断层具有最新活动特征,粘滑标志明显。另外清水沟老断层在全新世时也有新活动。

CHARACTERISTICS OF SURFACE TEXTURES OF QUARTZ GRAINS FROM FAULT GOUGE OF SOME ACTIVE FAULTS IN THE MINLE BASIN AND THEIR SEISMOGEOLOGICAL IMPLICATION

In this paper we go into in detail the surface microtextures of quartz grain from fault gouge of three active fault in the Minle Basin, and discuss sliding behavior and relative ages of these faults based on the surface characteristics of quartz grains. Results indicate that the central segment of the Yingluoxia fault is in stick slip, but both its two ends are in creep slip. Paleoearthquakes located in the central segment of the fault (Heihekou) occurred approximately in the late pleistocene or early Holocene. The Cihu Fault in the region is recently active, its feature of stick slip is clear. It is presented that the old Qingshuigou Fault occurred in the Sinian period also was active during Holocene epoch.