The Block Diagram is composed of five beds of rock. Black basement extends downward from the oldest bed. White sky extends upward from the youngest bed. The structures in the Structures menu let you convolute these beds.
The question mark in a structure's dialog indicates that the parameters of the dialog are missing, incomplete, or incorrect. You will find specification details in the Help menu. Note that it is not necessary to put the degree sign (°) in your parameters.
You may change dialog parameters at any time, even while the Block Diagram is being redrawn. The Block Diagram will redraw itself whenever there is new information.
Up to seven structures may be superposed upon the Block Diagram. When you choose a structure, its icon will appear in the History window. Use the History window to:
• show the order of geological events.
• select a structure dialog in which to work.
(Click on the associated icon.)
Use "Flat Beds" in the Structures menu to reset the Block Diagram.
