Abstract: The basic characteristics of Gama Ray (GR) and dual laterolog (DLL) in volcanic lithofacies are obtained based on the analysis of the well logging data of volcanic rocks in Xingcheng area of Songliao Basin. The logging characteristics are as follows: Except that basalt shows low value of GR and tuff shows low value of DLL in volcanic neck subfacies, the others show high value of GR and media value of DLL in volcanic vent facies. Explosive facies shows low value of DLL except showing media-low value of DLL in subfacies of air fall. The lithology of effusive-facies volcanic rock can be distinguished by GR logging. Effusive facies shows low or media-low value of DLL. Extrusive-facies volcanic lava shows high value of GR and low or media-low value of DLL. Extrusive and subfacies tuff lava shows media value of GR and DLL. This paper illustrates the practical application of logging data in the identification of special lithology of lithofacies from volcanic facies so as to identify lithofacies and lithology by making comparative analysis of the logging characteristics mentioned above.

Key words: logging data, volcanic lithofacies, characteristic, application, Songliao Basin, Xingcheng area