Data-driven weathering layer statics for hardrock imaging: Solutions based on first-breaks and surface waves

Seismic methods are routinely used for hardrock imaging and mineral-exploration purposes. However, hardrock seismic data requires careful processing, where weathering layer - refraction static corrections have shown to be of great importance for successful imaging. In our study, six differently obtained data-driven weathering layer static solutions are analyzed and compared using a seismic dataset from a mining site in Sweden. Three of the six approaches utilize first-breaks and are based on (1) the standard refraction-inversion method (RI), (2) the application of the RI after adding additional first-breaks via supervirtual seismic interferometry (SVSI), and (3) a tomography-based static solution (Tomostatics). The other three approaches employ surface-waves and are based on (4) the direct transformation of SW dispersion curves, (5) joint inversion of dispersion curves as well as first-breaks and (6) surface-wave tomography. All tested methods were successful in enhancing coherency of the main ore body reflection. A crosscutting reflection can also be seen following the first-break based refraction statics, with highest coherency seen after the application of the SVSIenhanced RI refraction statics. The examples presented suggest that these methods can be complementary and in the absence of notable first-breaks, surface waves can be utilized to estimate weathering layer static corrections.