Early flow paths can be traced along structural segments (single fractures, fracture intercepts, or zones of closely spaced fractures) through hundreds of kilometers of branchwork caves in structurally complex settings along the eastern Allegheny Plateau of West Virginia, USA. Identification of the early fracture conduits presupposes the following primary conditions: (1) prominent fracture traces are retained on bedrock perimeters; (2) fracturing associated with later cave enlargement is minimal and distinguishable from transmissive fractures; (3) conduit enlargement and modification are not so extensive or so directed as to have totally destroyed the fractures; and (4) there is minimal covering of relevant fracture traces by clastic or chemical sedimentation. Criteria used to infer structural segments include: (1) the presence of anastomoses or other dissolutional features along fractures; (2) the presence of tubes, half tubes, or segments of passage concordant to fractures; (3) the existence of anastomoses and other tubes that grow upward from initially transmissive fractures; (4) the presence of features of entrenchment that are lower than remnant tubes, half tubes, and most early parts of joint fissures; and (5) the continuity of flow along fractures, except at locations of dissolutional mining to create mined segments. If structural segments are identified and mapped with high-precision leveling surveys, a framework can be provided to decipher many details of flow-path integration and enlargement. It is then possible to reconstruct cave history using evidence provided by analysis of passage morphology, sediments, and the relationships of cave features to local and regional surface features.

The Blue Ridge and Great Valley of western Virginia are part of a detached master thrust sheet that extends through the central-southern Appalachian change of trend and has a root zone situated east of the Blue Ridge under the Piedmont. The mapped Pulaski fault and North Mountain fault crop out in the Great Valley as splay faults terminating in thrust tip anticlines and merge at depth with the buried master detachment floored primarily in Upper Ordovician Martinsburg Shales. Overall transposition of the thrust sheet from the root zone indicates that as much as 32 km (20 mi) of displacement may be translated westward into the Valley and Ridge proper and Allegheny Plateau as initial cover shortening above the Martinsburg Shale. Within the Great Valley and into the Roanoke recess at the juncture of the central and southern Appalachians, much of the cover shortening of this master sheet is accommodated by the Pulaski and North Mountain faults. From northeast to southwest, movement on the outcropping and buried master segment of the North Mountain fault decreases, and the surface fault terminates in southern Rockbridge County. Displacement on the Pulaski fault increases from northeast to southwest, and we infer that it assumes the decreasing displacement on the outcropping and buried segments of the North Mountain fault by displacement transfer.