Mark the vertical pixel positions of geologic time intervals on the chart. Search for an interval, then click on the chart to set its top and bottom positions.
Placing:
Click the top boundary on the chart, then the bottom.
Mapped Intervals
Click anywhere within a mapped interval on the chart to place a surface. A popup will appear to optionally name it and choose a type. Click repeatedly to place multiple surfaces.
Surfaces
Draw a box on the chart to define a unit. The top and bottom edges snap to the nearest surfaces. A popup lets you name the unit and assign it to a column.
Units
Select a unit to assign lithologies, commodities, and depositional environment.