PDF: | |
Time: | 2011 |
Journal: | Chinese Journal of Geophysics |
Volumn: | 54 |
Issue: | 2 |
Pages: | 697-610 |
Type: | Other |
Author: | Pujun Wang,Gongcheng Zhang,Qian Meng,Baoliang Lu,Defeng Zhu,Xiaomeng Sun. |
Abstract: | Materials comprising volcanogenic successions are derived from erupted components and transported by lava/pyroclastic flows and fallout as well as reworking processes. Their buildups are substaintial allostratigraphy and quite different from all kind of sedimentary sequences. The same with sequence stratigraphy for sedimentary rocks, voleanostratigraphy focuses on filling patterns confined by sequence boundaries, and depicts geological features and correlation of the successions in a volcanic basin. Some volcanic seismic facies units, including inner seaward dipping reflectors (SDR), landward flows, outer high and feeder dikes, were recognized in northern margin of the South China Sea based on the concepts of seismic volcanostratigraphy, indicating volcanic rifted margin. For volcanogenic successions of the Songliao Basin, it was realized that there are three types of sequence boundaries, in descending order of formation, member, and volcanic cycle, and that there are five patterns of basin filling i.e. aggradation, progradation, draping, mounding and cutting. Inland basins and continental margins are two branches concerning the applications of seismic volcanostratigraphy. By comparison, intrafacies components/components associations (4^th tier) and facies associations (3^rd tier) were three-dimensionally described in inland basins. On the other hand, seismic facies (2^nd tier) like SRD and landward flows were globally developed in the marginal basins (cf. first tier heterogeneity is on the scale of graben). Optimizing combination of the two branches will make seismic volcanostratigraphy more fruitful. |