# Reconstruction of Land and Marine Features by Seismic and Surface Geomorphology Techniques
## 4 Seismic Sedimentology  
Seismic sedimentology is the use of seismic data in the study of sedimentary rocks (lithology, thickness, and fluid properties) and the depositional processes by which they were formed by revealing their sedimentary and erosional geomorphology and their relationship with preserved landforms [43; 103; 104; 105]. The main tools of seismic sedimentology are ninety-degree phasing of the seismic data, seismic lithology, seismic slicing, and seismic geomorphology [43]. In addition, a display of seismic attributes on geologic time surfaces is another important tool of seismic sedimentology. However, there are strict limitations and conditions under which reservoir geometries and geomorphology can be optimally delineated on time and/or horizon slices [43; 106]. This seismic sedimentology approach, which attempts to resolve the resolution of seismic reflection data, is a supplement for the existing seismic stratigraphy where the seismic response to sedimentary layers and geomorphological surfaces may act differently at low and high resolutions [43]. The ninety-degree phasing of seismic data attempts to provide the best correlation between the seismic trace, wireline lithologic logs, and stratigraphic architecture (especially in a thin-bed depositional unit) by providing a symmetrical waveform to be tied directly with the acoustic impedance profile [43; 104; 107; 108]. The unique and symmetrical ninety-degree phasing of seismic data will eliminate the dual polarity of the thin-bed response (less amplitude distortion) that created better seismic image of thin-bed reflection termination and configuration (seismic facies), lithology, impedance profiles, and stratigraphy [43; 107; 108]. Seismic lithology is a reservoir geophysics technique that converts seismic traces into acoustic impedance logs (seismic inversion) to produce an acoustic impedance volume (valid impedance model) for lithologic and stratigraphic imaging at high resolutions [43; 106; 104]. This seismic sedimentology technique is very useful for identification and characterization of the thin-bed reservoir from 3D seismic reflection data. The thin-bed parameters might be consisting of (but not limited to) sand/shale ratio, lithofacies, shale (sand) content (as a pseudo-log), thickness of sandstone, etc. In addition, [PERSON], [PERSON], and [PERSON] [21] provide the relationships between lithology (sandstone and shale), fluid, porosity, clay content, and acoustic impedance that can validate seismic lithology results, which are:  
* Shale with medium-porosity gas sand. * Shale with low-porosity gas sand. * Gas sand and wet sand. * Wet sand and shale. The seismic slicing technique usually consists of time or depth, horizon, and stratal slicing types in 3D seismic reflection data that (together with seismic attribute) provide the geomorphology of geological features (Figure 2). The time or depth and horizon seismic slicing are self-explanatory, whereas the stratal slicing technique utilizes the horizontal seismic resolution of 3D seismic reflection data and spatially correlates the geological interpretation (especially at reservoir scale) in a geological timeline (Chronoststratigraphy). Nevertheless, [PERSON] [109; 110] suggests that some of parameters need to be understood to make this technique valid, which are:* Good quality geologic-time framework should be in place. * Depositional system should be linear with lateral changes in thickness. * No significant angular unconformity. Based on the analytical technique, seismic geomorphology involves the extraction and study of preserving subsurface landforms that utilizes plan-view images from 3D seismic reflection data by seismic slicing and seismic attribute techniques [27; 29; 43; 111].