Abstract The delineation of lineations, natural linear features on imagery that represent fractures, is a particularly difficult task in areas that have long human histories. Man-made linear features may also be visible and can either lead to erroneous interpretations or assist the interpreter to correctly identify the lineations. It is thus often useful to obtain information about the history and culture of an area, particularly if human occupancy has occurred over millennia. Dartmoor in southwest England has a human history dating from at least 4000 B.C., and examples from this region are used to illustrate the impact of past human activity on the interpretation of lineations on aerial photography. Bronze Age field boundaries (reaves) extend for great distances across the landscape, and unless one knew such features existed, they would surely be interpreted as natural linear features. Reaves are long, linear, and often parallel, and tend to cross the landscape in the same manner as lineations, regardless of the terrain. Features associated with the long mining history on Dartmoor also affect the interpretation of linear features. Surface mining of stream gravels inhibits the use of stream courses as indicators of lineations and also affects the use of valley boundaries. Linear surface excavations and rows of shafts, on the other hand, can often be used as indicators of lineations. Skill and experience are thus required to accurately interpret lineations; the greater the skill, experience, and knowledge of the human history of the area, the more complete and accurate the delineation will be.

Abstract Knowledge of three-dimensional, subsurface fracture patterns is necessary to solve many military and engineering problems. An understanding of subsurface fracture patterns is also essential for the field army with respect to penetrability and weapons effects. Many areas of the world in which the army has an interest are inaccessible (denied areas), and analysis of remotely sensed imagery provides a way to get needed information. This chapter describes a method that provides the basis for three-dimensional characterization of fracture patterns using remotely sensed imagery. Analysis of fracture patterns in the Dartmoor granite of southwest England shows that lineations delineated on imagery are very long, widely spaced joints that are members of joint sets found in outcrop. There are no statistically significant differences in orientation between joints and lineations; the smaller image scale allows the more widely spaced and longer members of a given joint set to be seen. With these relations established, fractal analysis of joint and lineation patterns on Dartmoor granite and in the East Pioneer Mountains, Montana, was done to determine whether fractal geometry could be used to predict subsurface fracture patterns. On Dartmoor, mean fractal dimension for vertical joint sets from outcrop and lineation patterns from imagery were comparable, but this was not the case for the Pioneer granites. Further research must address the problem of predicting three-dimensional, subsurface fracture patterns using remotely sensed imagery prior to attempting to meet the needs of the field army in denied areas.