CORRELATION OF SEISMIC ANOMALY TO ORGANIC REEFS BASED ON THE DISTRIBUTION OF SEDIMENTARY FACIES IN THE CHANGXING FORMATION IN NORTHEASTERN SICHUAN

Twelve seismic anomalies have been found in northeastern Sichuan and its adjacent areas according to the direct or indirect criteria used for recognizing seismic anomalies. They can be classified into three types: lenticular seismic anomaly, elongated seismic anomaly and unreflecting seismic anomaly. All these anomalies occur above the T₈ reflector or in the sedimentary facies and organic reefs in the Changxing Formation, the author contends that the seismic anomalies are associated with the organic reefs rather than the other factors such as hummocky sandstone bodies, igneous masses, salt and mud mounds. Thus the potential seismic anomalies are determined on the basis of the characteristics of the seismic anomalies and well data.