Time management in the EM

Time Nodes

The representation of nodes in the EM also allows the temporal dimension to be handled, indicating whether SUs are still in existence. Single SUs still existing are represented with a rectangle, SUs in series with an ellipse, while the continuity of a SU’s life through the phases is represented with a black rhombus.

Continuity nodes

The Extended Matrix makes it possible to represent the lifespan of a stratigraphic unit, enclosed between the moment of its execution and the moment of its destruction or de-functionalisation. In EM, the continuity of life is expressed through a continuity node (a black rhombus that marks the end of the life of the stratigraphic unit (the beginning is marked by the stratigraphic unit itself).