Calibration of Seismic Reflectors Inferred from Observations at the Chinese Continental Drilling Area

Abstract

AbstractGeophysical investigations have been carried out for the Chinese Continental Scientific Drilling Project (CCSDP), including 2D seismic reflection, MT, brevity and magnetic surveys. Seismic surveys show that many reflectors, such as dipping reflectors and arch like reflectors, exist in the upper crust of the drilling area. Based on cores and well‐logging data from a CCSDP pre‐pilot hole, VSP data and synthetic computations, this paper demonstrates that the dipping reflectors can be caused by high‐velocity eclogite bodies, fractures and ductile shear zones. However, the arch like reflectors may come from steep eclogites plus low‐velocity fractures. As the upper crust usually contains metamorphic rocks, the interpretation proposed in this study should be useful for calibration of deep reflection signals.