山东安丘古近纪冲积层中的地震记录

Seismic Records in Paleogene Alluvial Layers in Anqiu, Shandong

在山东安丘市沂沭断裂带分布区,发现古近纪朱壁店组冲积相沉积中发育一些震积岩层,它们是一套以振动液化砂岩墙、液化砂岩脉、裂隙充填砂砾岩墙、震塌岩、震成小断裂及塌陷构造等为震积特征的震积岩组合。这些古近纪震积岩表明,沂沭断裂带在新生代早期是一个构造活动强烈、强地震频繁发生的时期。由这些震积岩所记录的地震灾变事件,是该地区继燕山构造旋回结束后进入喜马拉雅构造旋回的响应。安丘古近纪朱壁店组震积岩的发现,为研究沂沭断裂带的活动史及区域地层调研提供了新的实际资料。

Some seismo-dcpositional layers are discovered in the alluvial facies of the Paleogene Zhubidian Formation in Yishu fault zone area of Anqiu City, Shandong. They are a set of seismites with seismo-depositional characteristics such as vihration liquefied sand dykes, liquefied sand veins, sandy conglomerate dykes caused by fissure filling , seismic fall-masses, seismic small-scale fractures and collapse structures and so on. These Paleogene seismites indicate that tectonic activity was intense anti strong earthquakes were frequently in Yishu Fault Zone during the Early Cenozoic Era. Seismic events recorded by these seismites are the responses to the Himalayan Tectonic Cycle after the Yanshan tectonic cycle. The discovery of seismites in the Paleogene Zhubidian Formation of Anqiu gives some new materials for studying the active history of Yishu Fault Zone and regional stratigraphy.