The Burnsville fault juxtaposes Precambrian Laurentian crust and the Ashe metamorphic suite within the Fries thrust sheet of the Blue Ridge thrust complex of western North Carolina. The Burnsville fault and adjacent Ashe metamorphic suite accommodated high strain at amphibolite facies (~700 °C and ~9 kbar) during the Acadian orogeny and then were tilted southeast during Alleghanian thrusting. Deformation resulted in three kilometer-scale structural domains: the Burnsville fault dextral strike-slip domain, the “transitional” domain, and the Otter Knobs domain. Structures recording the finite flattening plane are subparallel; those southeast of the Burnsville fault shear zone are rotated counterclockwise by ~10°–15°, consistent with a component of dextral shear. Across strike into the transitional domain, shear sense indicators become scarce, fabric grades to S > L, and lineations change from subhorizontal to downdip. Across strike into the Otter Knobs domain, lineations grade to moderately southwest-plunging, and the orientation distribution of poles to foliation indicates moderately southwest-plunging folding. The macroscale Otter Knobs fold, a tight-to-isoclinal synform in which the hinge line, associated lineations, and minor fold hinges plunge moderately southwest, is interpreted to represent this structural element. No evidence of oblique or reverse shear is observed. The across-strike changes between these coeval domains are consistent with heterogeneous wrench-dominated (10°–20° from the plate boundary) transpression. Changes across strike from the Otter Knobs domain into the transitional domain record part of the deformation path for a zone with an “effective” convergence angle of 14°–18°, including the rotation of structures recording the maximum incremental stretch.

Abstract The Hunters Crossing landslide is a slow-moving, weathered rock slide affecting a small community of condominiums in the town of Waynesville in the Blue Ridge Mountains of Haywood County, North Carolina. In November 2005, studies were begun to assess the characteristics of this landslide and the potential for further movement and damage to structures. Work included drilling several boreholes, performing seismic velocity surveys, and surveying benchmarks among other investigations. Data indicate that the potential failure surface is located no more than 11 m below the ground surface, possibly at the contact between saprolite and partially weathered rock. However, inclinometers installed at two locations on the slope have not detected enough movement to corroborate that assessment. Studies continue at this site to determine the location of the failure surface, to identify the mechanisms that accelerate movement, and to relate these findings to a broader understanding of weathered rock slides elsewhere in the southeastern USA.

The Mount Hay block is a ~12-km-thick, deep continental crustal section exposed in the Arunta inlier in central Australia. The ~4-km-wide, granulite-facies (770–776 ± 38 °C) Capricorn ridge shear zone cross-cuts the dominant granulite-facies fabric of the Mount Hay block. In its present geometry, the Capricorn ridge shear zone contains a steeply south-southeast-dipping foliation, steeply east-southeast-plunging lineation, and south-side-up shear-sense indicators. When post-granulite-facies tilting is removed, the shear zone restores to a shallowly to moderately (30–50°) dipping, normal shear zone in which the lineation is oblique to the inferred Proterozoic plate boundary, suggesting oblique divergence. The field observations and reconstruction indicate that strain can be localized in the high-temperature, deep-crustal roots of extensional fault systems. This geometry of a discrete, moderately dipping, deep-crustal shear zone is consistent with simple-shear conceptual models of crustal extension.