Dip flanks exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted.

Upthrown Fault flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. The upthrown fault has both Juxtaposition (J) and Fault Plane (P) risk elements.

Up and Downthrown Fault flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. The variable up and downthrown fault has both Juxtaposition (J) and Fault Plane (P) risk elements. At some point along the fault there must be a zero juxtaposition (J) throw point (which is shown on figure) such that fault plane seal (P) will likely be required for the fault to be effective.

Downthrown Fault flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. The upthrown fault has both Juxtaposition (J) and Fault Plane (P) risk elements. Downthrown faults are always riskier than upthrown faults because 2 different seals are always needed instead of one.

Onlap flanks can only exist with a base seal. The base seal must be unconformalble (U) or a combination of U with or without other top seal elements (C,d). Top and base seals can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. Onlaps differ from facies change/pinchout flanks (F) in that the time equivalent section to the reservoir is not present in the lateral seal section. The lateral seal risk (L) is commonly a sub sesimic transgressive sand so deep marine onlaps (with pelagic drape) are less risky than shallower littoral and non-marine onlap traps.

Subcrop flanks can only exist with a base seal. The top seal must be unconformalble (U) or a combination of U with or without other top seal elements (C,d). Top and base seals can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. Subcrops differ from facies change/pinchout flanks (F)in that the time equivalent section to the reservoir is not present in the lateral seal section. The lateral seal risk (L) is commonly a sub sesimic transgressive sand which frequently pressure connects different subcropping units in larger traps.

Erosional/Incision flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, onyone faulted or both faulted. The erosional process can be either submarine or subarial. Typically the lithology deposited in the canyon/valley fill section is the key risk element.

Diapiric Fault flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted.

Pinchout flanks can exist with or without base seals. Top and base seals (when present) can be unfaulted or faulted (t) in various combinations ie both unfaulted, only one faulted or both faulted. Pinchouts differ from subcrops and onlaps in that the time equivalent section to the reservoir is present within the lateral seal section. Facies Change/Pinchouts can be facies changes or diagenetic or other more complex permeability change boundaries.