The Cretaceous microfossils in the Songliao Basin are characterized by abundance

wide-spreading and rapid evolution. Ostracods could be divided into 15 assemblage zones

sporo-pollen 5 assemblage zones

charophytes 4 assemblage zones. Some of the assemblage zones bear certain correspodent relationship to seismic wave groups

and could be used as the basis for stratigraphic division and correlation. The correspondences may be divided into two kinds:1. as boundary surfaces of series such as T

4

1

T

3

1

and T

3

1

wave groups which are related to tectonic movement

and coincided with the evolution of organisms

formation types and paleoclimates; 2. as lithologic revelation for example T

1

and T

2

wave groups are usually the standared reflective horizons for regional stratigraphic correlation.