Changes

Higher resistivity on electrical logs shows the brittle, more fracturable benches within the Niobrara. Constructing a detailed [[Geological cross sections|cross section]], showing fracturable benches, maximum bed curvature, and any surface and subsurface [[Fault trap regime|normal fault]]ing, allows the explorer to visualize and accurately plot the angle at which the well bore must be drilled to penetrate the critical elements.

Higher resistivity on electrical logs shows the brittle, more fracturable benches within the Niobrara. Constructing a detailed [[Geological cross sections|cross section]], showing fracturable benches, maximum bed curvature, and any surface and subsurface [[Fault trap regime|normal fault]]ing, allows the explorer to visualize and accurately plot the angle at which the well bore must be drilled to penetrate the critical elements.

[[Seismic data|Seismic surveys]] are not particularly helpful in mapping normal faults because they are listric with about 100-300 ft of throw at the surface and about 30-80 ft of throw in the Niobrara. The faults are usually not present below the Niobrara. Therefore, although the Mesa Verde provides good seismic marker beds, the underlying Mancos and Niobrara

[[Seismic data|Seismic surveys]] are not particularly helpful in mapping normal faults because they are [[Fault trap regime|listric]] with about 100-300 ft of throw at the surface and about 30-80 ft of throw in the Niobrara. The faults are usually not present below the Niobrara. Therefore, although the Mesa Verde provides good seismic marker beds, the underlying Mancos and Niobrara

Formations usually do not have them. Occasionally, upward-lying normal faults will produce. [[Seismic data]] are useful in delineating these faults because good marker beds are usually present below the Niobrara. The fault can then be projected upward and is sometimes associated with a dim spot due to attenuation of [[seismic data]] in fracture zones.

Formations usually do not have them. Occasionally, upward-lying normal faults will produce. [[Seismic data]] are useful in delineating these faults because good marker beds are usually present below the Niobrara. The fault can then be projected upward and is sometimes associated with a dim spot due to [[Vertical and lateral seismic resolution and attenuation#Attenuation|attenuation]] of [[seismic data]] in fracture zones.

[[:file:developing-a-philosophy-of-exploration_fig1-3.png|figure 2]] is a Niobrara structure cross section.

[[:file:developing-a-philosophy-of-exploration_fig1-3.png|figure 2]] is a Niobrara structure cross section.