Objective Jiaojia fault belt is one of the most important gold mineralization belts in the northwest of Jiaodong, and more than 20 gold deposits have been identified within the belt and its branch faults, with discovered gold reserves exceeding 1000 tons.Goldorebodies mainly occur at the turning point of the dip angle of the fault, which constitutes a "stepped" distribution pattern. With the increase of exploration depth, the exploration resolution of conventional geophysical exploration methods can no longer meet the demand for locating the "third metallogenicstep".
Methods In order to identify the deep structure characteristics of the Jiaojia fault belt, his study adopted 3D seismic detection method, which has the characteristics of high signal−to−noise ratio, high resolution and ultra−deep detection capability.Based on the previous geological and well logging data in study area, a geological model was constructed.
Results Through forward modeling analysis, it was determined that the characteristics of the same phase axis diffraction, dislocation and transverse continuity variation of the fault belt on the seismic section were related to the changes in the occurrence position of the orebodies and the occurrence changes of the fault belt. By using key techniques such as prestack noise elimination, static correction, velocity analysis, and poststack migration were used to obtain seismic profile with high signal−to−noise ratio, clearer wave group, clear breakpoints, and reliable structural morphology. Using the "geological cap" technique to calibrate the stratigraphic relationship between earthquakes and geology. The seismic reflection waves were also recognized, and the differences between the sectional reflection waves and the layered reflection waves inside the rock mass were clarified. The 3D fracture-controlled mineralization model was established through the integration of 3D seismic interpretation and borehole data.
Conclusions This study revealed that deep-seated faults within the Jiaojia fault zone exhibit alternating steep and gentle occurrences, with minimal impact from post-mineralization faulting, highlighting the significant efficacy of 3D seismic methods in structural geological interpretation.
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