Study On The Underground Structure In Daqing Area

Daqing is not only the important petrochemical production base in China, butalso is the most important economic, cultural, educational, medical, scientific researchcenters in west of Heilongjiang province. On tectonics, Central depression where inDaqing is the settlement centers of Songliao basin. Changyuan uplift area which is themain construction reservoir of oil in Daqing is mainly controlled by the faults. Theuplift area is still active at least in the Early-Middle Pleistocene. Ms5.1earthquake in2005occurred in Lindian, indicating that fault structure and crustal structure is notstable in the region. This shows underground construction in Daqing area is verycomplex. Therefore, both deep constructed or shallow structure study will help peopleunderstand the situation underground construction in Daqing. The study will helppeople to better understand the characteristics which of fault structures of Lindianearthquake and settlement centers of Songliao basin. Specific methods are as follows:1. Using Double-difference method relocated148earthquakes in Daqing region.Eventually,126the Seismic source parameters of earthquakes had been obtained.2. According to the results of the repositioning，Using seismic that has been meetthe conditions finished Focal mechanism solutions. using the data of Finished Focalmechanism solutions analyzed Modern tectonic stress field and inferredcharacteristics of modern tectonic activity and stress.3.Taking advantage of Qing-Ju WU researcher in Suifenhe-Manzhouligeoscience transect having layed on the flow of seismic array and Seismic stationshaving recorded information between2009.6-2011.5, According to method of LimitedFrequency Conducting tomography of Body wave travel time, have Getted theThree-dimensional P-wave velocity structure of Upper mantle in the study area; UsingRayleigh wave Double-Station phase velocity and background noise phase velocity tomography, have Inversed Three-dimensional S-wave velocity structure of the studyarea. Eventually, the two methods obtained a three-dimensional velocity distributionof Daqing area.4.Use Bouguer gravity anomaly data and aeromagnetic anomaly data retrievaldeep structure. Analysis of the deep structure and the scale of Daqing area.The results showed that:1.Repositioning of small earthquakes are more focused, and banded are moreobvious, with the structure of geophysical interpretation has a certain relationship.2.By the aftershocks direction, the isoseismal direction and Focal mechanismsolutions analyze the Seismogenic structure of Lindian Seismic. We speculate that itmay be the Daan-Dedu fault of NNE trending dextral strike-slip.3.Geophysical field results confirm Daan-Dedu fault is real, belonging tocrustal faults. The scale of Binzhou fault that was considered to be basement faults isrelatively small.4. Seismic Array confirmed that the earth’s crust of Songliao basin is thin andThe earth’s crust of Da Hinggan Mountains and Xiao Hinggan Mountains is thick. Thecrust often have low velocity anomaly in the Songliao Basin，The crust-mantleboundary and upper mantle show high velocity anomaly compared with thesurrounding, Analysis of the reason may be due to the rise of mantle material willcause local high-speed anomalies. Velocity anomalies is usually NS or NNE strike,This may be related to the impact of faults.