摘要
本文给出了新村盆地浅层地质结构的人工地震研究结果。测区第四纪复盖层厚度大于600m。400m以上观测到P_1、P_2、P_3、P_4 4个折射界面。P_1为主要界面,界面速度1.6—2.3km/s,埋深1—10m,厚度15—35m。P_2界面速度2.8—3.2km/s,埋深20—40m,厚度120—140m。P_3、P_4只在部分测线观测到。P_3界面已显示错断。 测区浅层地质结构相当复杂,速度横向变化及界面起伏较大,可以确定两条断层和一条宽度300m以上的破碎带,推测断层和构造6处。该结果为东川城市建设规划提供了基础资料,并为搞城市物探积累了经验。
This paper provides the result from the man-made earthquakes aimed at studying the geologic structures at shallow depth in the Xincun basin, Dongchuan area. Result from the study shows that the Quaternery overburden in the surveyed area is 600 m, and the 4 refraction interfaces respectively listed as P1、P2、P3and P4 are observed in the depth range above 400 m. P1 is the principal interface. It shows a velocity of 1.6-2.3 km/s, a burial depth of 1-10 m and a thickness of 15-35 m. P2 has an interface velocity of 2.8-3.2 km/s. It presents a burial depth of 20-40m and a thickness of 120-140 m. P3 and P4 are only observed along parts of the survey lines and the P3 interface also shows evidences of being offset.The geologic features at the shallow depth of the surveyed area shows extremely complicated structures, transverse velocity changes and remarkable fluctuations of the interfaces. It can be identified that the area is associated with 2 faultings and a fracture zone measuring at least 300 m. It has also been deduced that there might exist 6 faultings and geologic structures in the surveyed area. The result from our study has not only provided basic data for the construction planning of Dongchuan City, but also cumulated experiences for the geophysical exploration of the said city.
出处
《地震研究》
CSCD
北大核心
1990年第4期411-417,共7页
Journal of Seismological Research
关键词
地震
勘探
折射波
新村盆地
浅层
Onset refraction waves
Surface-layer removal method
Time delay
