Experimental (clay) and analytical models suggest that regional strain, either extension or compression, significantly affects fault patterns produced by doming. Our models simulate the shallow deformation produced by gentle doming of a homogeneous material with and without a simultaneously applied, regional horizontal strain. The models show that without regional strain, randomly oriented normal faults develop on the crests, and radial normal faults form on the flanks of circular domes. With regional extension, normal faults on the crests and flanks of circular domes trend perpendicular to the applied extension direction, and strike-slip faults trending 60° from the regional extension direction form on the flanks. With regional compression, normal faults on the cres s and flanks strike parallel to the applied compression direction. Strike-slip faults trending 30° from the regional compression direction also form on the flanks, and reverse faults striking perpendicular to the regional compression direction develop on the peripheries. Our models show that regional strain affects the fault patterns produced by elliptical doming.

This study has important implications for hydrocarbon exploration. The models provide guidelines for determining the strike of faults on domes and suggest that strike-slip and reverse faults, as well as normal faults, may form during doming. These faults may influence hydrocarbon migration and entrapment. Strike-slip faults develop on domes formed in the presence of regional extension (for example, many Gulf Coast domes). Strike-slip and reverse faults develop on domes formed in the presence of regional compression (for example, several domes of the Rocky Mountain foreland province).

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