Sedimentary Processes - Examples from Asia, Turkey and Nigeria

This book contains six chapters dealing with the sedimentary processes with examples from Asia, Turkey and Nigeria, particularly referring to the geological characteristics, to the beach processes, to the coastal and lacustrine sedimentary archives and to the role of the mangroves in controlling the coastal sedimentation, pertaining, in particular, the geological characteristics and the production response of a reservoir located offshore the Niger Delta (Nigeria), the coastal lacustrine geo-archives with the example of the Lake Bafa (Turkey), the sedimentary processes in the riparian zone of the Ruxi Tributary Channel (Three Gorges Reservoir, China), the beach morphological changes studied by means of a contour-line change model and finally, the role of the mangroves in controlling the sedimentary accretion of coastal and marine environments with the regional example of the south-eastern Asia. The first chapter introduces the sedimentary processes and related geological controls, examining the role of the deltas (Niger Delta), the coastal and lacustrine geo-archives, the beach systems and their morphological variations and the geological role of mangroves. Using geophysical techniques as the analysis of the seismic attributes, in the second chapter it has been established that the N5.2 reservoir is a massive sandy unit, located in the Agbada Formation, representing a structural high, characterized by two main peaks. The correlation of well logs has been performed, highlighting the occurrence of sandstones with traces of glauconites. In the third chapter, the coastal and lacustrine sedimentary archive of the Lake Bafa has been analyzed, individuating four main depositional stages, ranging in age from 4.5 ky B.P. to 0.8 ky B.P. The ecosystem characteristics of the basin have been controlled by hydroclimatic and geotectonic processes. The fourth chapter has applied a fingerprinting technique to the sediment sources of the riparian zone, taking into account several depths of a tributary channel. The main sediment sources are represented by the topsoil above the riparian zone, by the sediments suspended by the Yangtze river and by the sediment suspended by the Ruxi river. The fifth chapter has studied the long-term variations of the beach of the Kaike coast (Japan), starting from the analysis of aerial photographs and then producing a contour-line change model, which has considered the variations of sediment grain-size. In the sixth chapter, marker horizon techniques and surface elevation table (SET) tests have highlighted the spatial variability in the sedimentary patterns by examining several coastal sites, especially located in Malaysia and Thailand (south-eastern Asia).