Chronosomes are represented on a chronographic chart as contemporaneous layers of sediment expressed as functions of time. On the chronostratigraphic chart these are horizontal. They represent sediment of equivalent age, deposited over a depositional surface from up-dip to down-dip.

 

A Wheeler diagram identifies and maps the geographic location and order in which sedimentary units, bounded by discontinuities, accumulated in stratigraphic cross-sections. The chart displays these contemporaneous units in the order they were laid down and their location. As explained these units are represented as horizontal layers of sediment known as "chronosomes" bounded by time planes (see figure above). The horizontal axis of the chart match the horizontal dimension of a seismic, geologic, or well cross section and vertical axis represents time. Using the Wheeler diagram it is possible to infer how fast sediment accumulated before an unconformity developed or much sediment was eroded over an unconformity and where source rocks and reservoirs are likely to accumulate