Termination of a Major Normal Fault

GEOTHERMAL ENERGY

Termination of a Major Normal Fault:

Major normal fault terminations or tip-lines sometimes split into multiple closely-spaced faults that result in increased permeability. Fault sets at these terminations sometimes appear as "horsetailing" splays that facilitate hydrothermal fluid migration in the subsurface.

Other definitions:Wikipedia Reegle

Controlling Structures

List of controlling structures typically associated with geothermal systems:

• Major Normal Fault
• Termination of a Major Normal Fault
• Stepover or Relay Ramp in Normal Fault Zones
• Apex or Salient of Normal Fault
• Fault Intersection

• Accommodation Zone
• Displacement Transfer Zone

• Pull-Apart in Strike-Slip Fault Zone
• Intrusion Margins and Associated Fractures
• Stratigraphic Boundaries
• Fissure Swarms
• Caldera Rim Margins
• Lithologically Controlled

Terminations of major normal faults, whereby faults break up into multiple splays or horsetail. Illustration by James E. Faulds.

Faulds uses this term as a structural control found in the Basin and Range province of the US.

Major normal faults sometimes terminate into multiple horsetailing splays that result in increased hydrothermal fluid flux. As of 2011, 22% of all known Basin & Range structures hosting geothermal systems occur at normal fault terminations or tip-lines with multiple closely-spaced faults that enhance permeability.

Examples

Want to add an example to this list? Select a Geothermal Resource Area to edit its "Controlling Structures" property using the "Edit with Form" option. CSV