| PDF: | |
| Time: | 2010 |
| Journal: | Acta Petrologica Sinica |
| Volumn: | 26 |
| Issue: | 1 |
| Pages: | 121-129 |
| Type: | SCI |
| Author: | Guodong Wang,Rihui Cheng,Pujun Wang,Youfeng Gao. |
Abstract: | Drilling core from Chinese Continental Scientific Drilling-SK-I(s) presents four sets of deep lake seismite from the lower part of the second member to the bottom of the third member of Qingshankou Formation. Typical structures of the seismites include step micro-fault, seismic fissure bed, autoclastic brecciated structure, load structure, ball-and-pillow structure (pseudonodule), vibration-induced liquefaction structure, enterolithic structure, liquefaction sand dyke and pseudo-mud crack. All of these synsedimentary-penecontemporaneous soft-sediment deformation and absence of seismo-turbidite indicate that the seismites in Qingshankou Formation are previous soft sediment reconstruction related to earthquake. Seismites of Qingshankou Formation exhibit typical developmental pattern and sedimentary sequence of seismite. This seismic sequence consists of the lower unit of liquefaction deformation corresponding to strong earthquake and the upper unit of plastic deformation corresponding to earthquake attenuation. Mudstone with few altered glass shards and volcanic ash interlayers simultaneously developed in Qingshankou Formation from SK-I(s). Mugearite and volcanic breccia developed in well Jin6 and Jin65 and basalt developed in well Qian124 and Qian 109 during corresponding geological time of volcanic ash in SK-I(s). These four wells containing volcanic rock in Qingshankou Formation distribute along the Sunwu-Shuangliao transcrustal fault, which indicates that tectonic-volcanic activities occurred during Qingshankou period in Songliao Basin and seismites recorded earthquake activities induced by tectonic-volcanic event in deep water. Existence of tectonic-volcanic event in Qingshankou Formation suggests that fault activities and volcano eruptions should be normal phenomena during the sag stage in Songliao Basin. |