Processing method of deep seismic reflection data from the basin-range junction zone on the northeastern margin of the Qinghai-Tibet Plateau and preliminary geological understanding

Abstract：The basin-range junction zone has complex surface geological conditions and a rather undulate tomography, where deep seismic reflection data are characterized by a low S/N ratio, strong multifold noises and great lateral variation in velocity. According to the characteristics of these deep seismic reflection data, the authors used the ProMAX processing system to make refraction static correction, pre-stack noise attenuation, surface consistent processing, man-machine interactive velocity analysis, residual static correction circulating iterative processing, NMO based on surface and post-stack noise suppression on the 2-D deep seismic reflection data (or called the Spo4-2 profile) across the junction zone of the Zoigê basin and West Qinling orogen and found a set of processing method and flow process suited to the low S/N ratio deep reflection data of the basin-range junction zone. Finally they got the SP04-2 stacked section. The section for the first time reveals the lithospheric structure of the basin-range junction zone of the Zoigê basin and West Qinling orogen and offer a reliable seismologic basis for studying the contact relationships in the deep interior of the basin-range zone.