Abstract: There exist volcanic rocks developed in Anda fault depression with stratified, quasi-stratified and moundy occurrences. During deposition of Cretaceous Shahezi formation to Yingcheng formation, 3 large-scale volcanic activities were taken place, shap-ing volcanic rocks of explosion, overflow and sub-volcanic rock facies. These volcanic rocks were related in formation and distri-bution to deep rift in which the thin or crossing places tend to be the channels of volcanic explosion. Different reflecting charac-teristics ( e.g., evident amplitude reflecting feature) of these volcanic rock facies can be seen in the seismic profile. The basinal formation, regional structure and petroleum accumulation are closely related to the volcanic rocks within fault depression.

Key words: Songliao basin, Anda fault depression, volcanic rock, seismic reflection, amplitude