12.9 Basin-TyPe Transitions
12.9.5 Summary (Polyphase Basins)
Many existing and most of the ancient sedimentary basins have experienced a polyphase
history which can be subdivided into two or
several phases of structural evolution and basin
filling (tectono-stratigraphic units).
A cmde scheme of basin transitions on passive
and active continental margins is provided by the
"Wilson cycle". However, the evolution of many
basins is more complex.
Original basins and their sedimentary fills can be
partially or entirely inverted, i.e. they later form
structural highs which are exposed to erosion.
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The potential for preserving little deformed
and/or moderately metamorphosed sediment
decreases from intracontinental basins via
passive continental margin basins to active
margin and oceanic basins.
The deciphering of the history of polyphase
basins is one of the tasks of structural, regional
and historical geology. To solve this task with
success, the aid of experienced sedimentary
geologists is needed who are familiar with the
basic concepts of basin evolution.