Abstract:
The spatial distribution of aerogamma spectrometric and aeromagnetic anomaly in Shangnan-Danfeng area of the North Qinling Orogenic Belt has been analyzed in this paper, and then the corresponding tectonic units has been divided on the basis of high-resolution aeromagnetic and aerogamma spectrometric survey.A standard geophysical response mode of ophiolite complex in the North Qinling Orogenic Belt has been established by extracting its characteristics of aeromagnetic and aerogamma spectrometric anomalies. The characteristics of Songshugou ophiolite show that the ophiolite complex in the North Qinling Orogenic Belt has low radionuclide concentrations and high-amplitude positive anomaly. According the geophysical response mode of Songshugou ophiolite, the mafic-ultramafic rocks in Guojiagou area have been identified as the ophiolites. And then, the spatial distribution of Guojiagou ophiolite in Danfeng area has been delineated by the geophysical evidences that obtained from the high-resolution aeromagnetic and aerogamma spectrometric survey. Meanwhile, the Fenshuiling ophiolite and Mianyuzui-Qingyouhe mafic-ultramafic rocks in Danfeng area have been inferred and interpreted in this paper, and it's inferred that some ophiolites may be existed in Mianyuzui-Qingyouhe area.