The '''geographic extent''' of a petroleum system is determined at the critical moment. It is defined by a line that circumscribes the pod of active source rock and all oil and gas seeps, shows, and accumulations originating from that pod. [[:file:petroleum-systems_fig3-4.png|Figure 2]] shows the geographic extent of the fictitious Deer-Boar(.) petroleum system. | The '''geographic extent''' of a petroleum system is determined at the critical moment. It is defined by a line that circumscribes the pod of active source rock and all oil and gas seeps, shows, and accumulations originating from that pod. [[:file:petroleum-systems_fig3-4.png|Figure 2]] shows the geographic extent of the fictitious Deer-Boar(.) petroleum system. |