Along the southern segment, footwall bed dips define a structural high symmetrically disposed about the point of maximum throw.

A prominent hanging wall feature of the southern segment is the Moab Anticline, with a crestal collapse graben accommodated by an array of normal faults.

The sedimentation of the Moab area was primarily influenced by marine or lacustrine incursions into the margins of major Jurassic ergs.

Distinctive types of veining, calcite cementation and iron oxide reduction exist adjacent to the fault, especially in Jurassic Navajo and Entrada sandstones.

While fault rocks along the R191 location and Bartlett Wash are enriched in clays relative to protolith, those at Corral Canyon and Courthouse Canyon show little difference in composition relative to protolith, suggesting that fault rock formation at the latter locations is governed by mechanical as opposed to authigenic processes.

These conclusions support Chan et al.’s[7] hydrogeologic model, which proposes that hydrocarbon and basin brines from Pennsylvanian source rocks migrated along the Moab fault, moving into the porous sandstone units where they interacted with oxygenated meteoric water.

They determine a mineralization age of c. 25-20 Ma, which coincides with episodic uplift of the Colorado Plateau or with La Sal Mountains volcanism.

These observations, combined with the extensive presence of shaley gouge even at low stratigraphic levels suggest that the Moab Fault was a conduit for fluid flow while supporting significant across-fault pressure differences.

[9] Clay smear processes are applied to instances of cross-fault flow when porous and permeable rocks, specifically sandstones and shales, are cut by normal faults.

According to Foxford et al.,[1] the most important feature of the Moab Fault zone from the standpoint of seal potential assessment is the nearly constant presence of at least one shaley gouge layer.

The shale gouge ratio is one way to describe the amount of clay smear in a fault zone, and is simply defined as the percentage of shale/clay in the slipped interval.

[9] Shale gouge ratio, when applied to sand-shale sequences, indicates the proportion of phyllosilicate material expected to be incorporated into the fault rock.