STRUCTURAL ANALYSIS OF THE JACKSBORO FAULT IN THE PIONEER QUADRANGLE, TENNESSEE

The Pioneer quadrangle of Tennessee includes the intersection of Pine Mountain Thrust, Terry Creek Fault, and Jacksboro fault. The stratigraphic sequence along both sides of the Jacksboro fault belongs to the Lower Pennsylvanian, with the Crab Orchard Mountain and Gizzard groups at the base, and the Middle Pennsylvanian Redoak Mountain Formation at the top. Shale beds are dominant in almost all of the rock units except for the Lower Pennsylvanian groups in which conglomerates are dominant, and included throughout this section there are many sandstones and coal bed units. This study focused on deformation along the Jacksboro fault. The Jacksboro fault is the southwest boundary of the Cumberland Mountain over-thrust block that moved to the northwest during the Alleghanian Orogeny. This fault has been described by previous authors as a tear fault or as a lateral ramp. The length of the Jacksboro fault is 17 km. There is evidence of strain partitioning of thrust and strike-slip displacement on separate faults in some places in the fault system that makes up the Jacksboro lateral ramp. The large anticline on the hanging wall of the Jacksboro fault is due to the local transpressional conditions. Along the Jacksboro fault are horses that have been transported to the northwest, and one of these blocks has been transported to the intersection of Pine Mountain Thrust, Terry Creek Fault, and Jacksboro fault. The approximate displacement of the Pine Mountain thrust from using ramp and hanging wall cutoffs is 21 km. The approximate thrust and strike-slip components of the Jacksboro fault are 5 km and 16 km, respectively.