Evidence for Cenozoic topographic rejuvenation associated with the Laurel Creek Lineament in the Spruce Pine 7.5-minute quadrangle, western North Carolina, USA

Abstract

ABSTRACTLinear fracture systems that strike obliquely to rock units occur across western North Carolina and are associated with Cenozoic topographic rejuvenation of the region. A 2005 earthquake on fractures within one of these systems, the Laurel Creek Lineament, suggests it's an active system. Geologic mapping of the Spruce Pine 7.5-minute quadrangle was conducted to document fault kinematics on this lineament. Near-vertical joints and faults are exposed throughout the quadrangle and dominantly strike toward 080°/260°. Fault offsets were centimeter to meter in magnitude. Fault slip indicators suggest the north block moved up relative to the south block, supported by stream knickpoints that indicate disequilibrium on the northern block. Previous studies on the Boone Lineament, north of Spruce Pine, showed that fracture system moved with the south side up. These data indicate the block of crust between the Boone Lineament and the Laurel Creek Lineament has been uplifted by these fracture systems.

Keywords

• Laurel Creek Lineament
• geologic map
• Blue Ridge Mountains
• topographic rejuvenation
• orogenic uplift