Changes

==Mapping faults==

==Mapping faults==

[[file:M91Ch13FG84.JPG|thumb|300px|{{figure number|6}}This faulted top reservoir map from the Staffa field in the UK North Sea is represented by a contoured surface and fault polygons. The fault polygons show the hanging wall and footwall fault cuts for the interpreted surface. The downthrown (hanging wall) side of the fault is indicated by a blocked out symbol (from Gluyas and Underhill).<ref name=Gluyasandunderhill_2003>Gluyas, J. G., and J. R. Underhill, 2003, The Staffa field, Block 3/8b, UK North Sea, in J. G. Gluyas and H. M. Hichens, eds., United Kingdom oil and gas fields, commemorative millennium volume: Geological Society (London) Memoir 20, p. 327–333.</ref> Reprinted with permission from the Geological Society.]]

[[file:M91Ch13FG84.JPG|thumb|300px|{{figure number|6}}This faulted top reservoir map from the Staffa field in the UK North Sea is represented by a [[contour]]ed surface and fault polygons. The fault polygons show the hanging wall and footwall fault cuts for the interpreted surface. The downthrown (hanging wall) side of the fault is indicated by a blocked out symbol (from Gluyas and Underhill).<ref name=Gluyasandunderhill_2003>Gluyas, J. G., and J. R. Underhill, 2003, The Staffa field, Block 3/8b, UK North Sea, in J. G. Gluyas and H. M. Hichens, eds., United Kingdom oil and gas fields, commemorative millennium volume: Geological Society (London) Memoir 20, p. 327–333.</ref> Reprinted with permission from the Geological Society.]]

Structure maps show the contoured depth surface and a representation of any faults cutting the surface. The faults are drawn as fault polygons marking the hanging wall and footwall fault cuts for the interpreted surface. The hanging wall is the rock volume above the fault plane, and the footwall is the rock volume that lies beneath it ([[:file:M91Ch13FG81.JPG|Figure 3]], [[:file:M91Ch13FG82.JPG|Figure 4]], [[:file:M91Ch13FG84.JPG|Figure 6]]).

Structure maps show the contoured depth surface and a representation of any faults cutting the surface. The faults are drawn as fault polygons marking the hanging wall and footwall fault cuts for the interpreted surface. The hanging wall is the rock volume above the fault plane, and the footwall is the rock volume that lies beneath it ([[:file:M91Ch13FG81.JPG|Figure 3]], [[:file:M91Ch13FG82.JPG|Figure 4]], [[:file:M91Ch13FG84.JPG|Figure 6]]).