View source for Mandal-Ekofisk(!) petroleum system

==Petroleum system events chart==

[[file:petroleum-systems_fig3-11.png|thumb|300px|{{figure number|5}}Events chart. Modified from Cornford.<ref name=ch03r3 />.]]

An events chart indicates when the essential elements and processes took place to form a petroleum system, the critical moment, and the preservation time. In [[:file:petroleum-systems_fig3-11.png|Figure 5]], the source rock is the Upper Jurassic to Lower Cretaceous Mandal Formation, which was deposited as the rift formed. Most overburden rock of Cretaceous to [[Cenozoic]] age was deposited after the rift formed. The seal rock ranges from Permian to Neogene and consists of [[halite]], shale, and chalk. Based on volume of petroleum, the Permian to Jurassic reservoir rocks are least important; the most important reservoir rocks are Late Cretaceous to early Paleogene in age. Most traps were created as the rift formed and filled through structural movement and halokenesis. Petroleum generation-migration-[[accumulation]] occurred from just over 100 Ma to the present day. The critical moment, or peak generation, is at 30 Ma.