Vietnam has over 3200 km shoreline which extends from north to south of the country. Sea level changes were principal factors influenced on sedimentary environment and compositions. In Quaternary, cycles of sea level change and tectonic movement were main factor that created Red River delta, Nam Bo plain and Central plain. There are 5 sedimentary cycles corresponding to 5 cycles of sea level change of the Red River delta and Nam Bo plain. Sedimentary cycles were ...
A secondary basin corresponds with a second order depositioual cycle, is limited by two erosional surfaces which are also the boundaries of a seismic sequence. In other words, a secondary basin is a component of an overall sedimentary basin.
A secondary basin is formed at the same time with a tectonic phase where the tlu·ee most important factors are faulting, subsidence and uplifting. Basin-forming faults are usually normal faults and are called "syn-depositional fault".
The first version of this text was written to serve as lecture notes for a first term geology course in “Minerals and Rocks” at Aarhus Universityin Denmarkin 2003. In Aarhus this course is accompanied by a general “Introduction to Geology” course that presents, for example, the structure of the Earth, plate tectonics and paleontology. These topics are therefore not treated here, and some knowledge of the Earth´s structure and plate tectonicsis assumed.