Seismic Response and Wave Group Characteristics of Reef Carbonate Formation of Karloff-Oxford Group in Asser Block

Abstract

In this article, we built a reef complex geological model, which is based on the geological characteristics and electric characteristics on the upper Jurassic Karloff-Oxford Formation of Asser Block at the Right Bank of the Amu River, and studied seismic response of carbonate formation by the wave equation forward modeling. Seismic response characteristics of reef complex in the area are the mound-shaped and lenticular reflections characteristics. Seismic wave in the edges of the reef complex often appear onlap and diffraction seismic reflection phenomenon, and there is upper bend phenomenon on the top of the reflection wave. The reflection wave on the top of the reef complex is trough weak reflection, with weak amplitude and discontinuous wave-front. The internal reflection wave in reef complex are unorganized or weakly, and there is a big difference in continuity between it and that of the surrounding rock on the amplitude, frequency and phase. Moreover, compared with formations of two wings, we found out that the thickness suggested by the reflection waves in the internal reef complex is bigger. The characteristics mentioned above are consistent with seismic section characteristics of reef complex over well. So that, we built a characteristics to recognize pattern of seismic of reef complex by using forward modeling results of a reef complex.