Although earthquakes are rare in stable continental regions, some of them can occur at very shallow depth and cause serious damage. Recent studies suggest that such shallow earthquakes may be controlled by complex fault geometries. In this study, we investigate the extremely shallow 2020 Mw 5.1 Sparta earthquakesequence in North Carolina. Using the surface wave, we construct a 1D velocity model and verify the accuracy of the aftershock locations and depths. We find that about 90% of the aftershocks occurred in the top 3 km zone with low-velocity and strong velocity gradient. With help of local geological studies, we infer that this feature can be explained with the fault intersection model. These findings suggest that the Sparta earthquake likely occurred within a complex fault system, which contrasts with earthquakes in active continental regions featuring well-defined and manifest faults.