Structural analysis of the Hunter Valley, Wallen Valley, and Whiteoak Mountain fault intersection in northeastern Tennessee

Detailed mapping at 1:12,000 scale was done in the area of the Hunter Valley, Wallen Valley, and Whiteoak Mountain thrust fault inter section in Anderson County, northeastern Tennessee. Strain analysis was done on hangingwall and footwall rocks using mesoscopic Rome Formation and Rockwood Formation folds, deformed Rockwood Formation brachiopods, a deformed Rome oolite, and balanced cross-sections.

The structural data indicate that (1) the Wallen Valley thrust is a footwall imbricate of the Hunter Valley thrust, (2) the Wallen Valley thrust transfers its displacement to the older Hunter Valley thrust and together they are renamed the Whiteoak Mountain thrust, (3) more intense macroscopic folding (shortening up to 29%) occurs in the hanging wall of the older Hunter Valley thrust due to folding by the younger Wallen Valley thrust below, (4) both the Hunter Valley and the Wallen Valley thrusts are folded by a footwall horse of Ordovician rocks along the Wallen Valley footwall flat, and (5) footwall deformation via trailing imbricates and mesoscopic folding is greater than hanging wall deformation via leading imbricates and mesoscopic folding.

The data from strain analysis indicate that (1) whole rock strains in the Rome Formation oolite (due to stratigraphic overburden) are greater than the strains which are recorded by the individual ooids, (2) strain markers (Rockwood Formation brachiopods) which are proximal to large displacement thrust faults show greater deformation than strain markers (Rome oolite) which are proximal to small displacement thrust faults, and (3) the displacement and shortening on the Whiteoak Mountain thrust (9.87 km and 76%) is greater than the displacement and shortening on the Hunter Valley thrust (2.44 km and 53%) or the Wallen Valley thrust (8.5 km and 59%).