A new method is proposed for collecting and reducing large collections of lineament data. The method consists of three steps: (1) collection of lineament data using multiple observers, multiple observation trials, and several types of imagery; (2) reproducibility tests; and (3) domain overlap analysis. Collection of lineament data and reproducibility tests are performed by overlaying lineament maps drawn by several observers or by superimposing multiple maps prepared by a single observer and identifying lineaments which are coincident (coincident lineaments = lineaments that have azimuths within 5 ± and separation distances are within 1–2 mm at the scale of drawing). Domain overlap analysis is accomplished by measuring the trends of near‐vertical fractures at outcrops distributed over the study region and comparing the spatial distribution of these trends with similar‐trending coincident lineaments. Lineaments that are not reproducible and are not geographically correlative with fractures are considered unimportant and removed from the data base. The method was applied to a 44 km2 study area in Maine and resulted in a reduction in the lineament data base from 6500 to 217. Transmissivities determined for bedrock wells located within 30 meters of lineaments that are both reproducible and geographically correlative with outcrop‐scale fractures are generally higher than the transmissivities of wells located near lineaments that are not separated on the basis of these criteria. Application of the method serves as an important filter by providing a more manageable lineament data base from which to begin detailed field checking and/or geophysical surveys directed toward specific lineaments.

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Lineaments derived from three image types (1:80,000 black and white, 1:58,000 color infrared, and 1:250,000 side-looking airborne radar) were compared to water-bearing features within a 9.6 km section of tunnel being constructed through foliated crystalline metamorphic bedrock in a glaciated region of eastern Massachusetts. Lineaments drawn by three observers during two independent trials (N = 9137) were reduced to three sets (one per image type) of coincident lineaments (N = 794). Thirty-five coincident lineaments crossed the tunnel. Nineteen discrete flow zones, each producing > or = 19 L/min, were identified in the tunnel and used to quantify the reliability of lineament analysis as a method of predicting water-bearing features in glaciated metamorphic Thirteen (68%) of the flow zones correlate with coincident lineaments, six zones correlate with more than one image type, and one zone correlates with all three image types. Overall, without additional corroborating evidence, it is difficult to interpret in advance which lineaments will result in a successful correlation with water-producing zones in the subsurface and which ones will not. Most of the observed flow (80%) correlates with northwest-trending coincident lineaments; however, the majority of the flow (67%) associated with these lineaments is produced from structures that strike to the north or northeast. In addition, only 15 of the 35 coincident lineaments correlate with the flow zones, indicating that 20 lineaments are not associated with any appreciable flow. Six flow zones are undetected by the lineament analysis.

The configuration of six possible paleostress tensors have been derived from 152 faults measured in eastern Vermont and western New Hampshire. Populations of potentially genetically related faults were separated using two techniques. Tensor configurations for each population were derived using a linear least squares inversion method based in part on the work of Reches [1987] and a grid search inversion method which tests over 100,000 possible tensors for compatibility with all or portions of the data. Faults belonging to the oldest population (set R; n=24) occur primarily in high‐grade rocks. This set is composed of semiductile, northeast trending reverse and west–northwest trending left‐lateral faults. Fault fabrics of quartz rods and thin mylonite layers suggest that the host rocks were at crustal levels of 8–10 km during faulting. The derived tensor indicates a roughly east–west σ1 and near vertical σ3. Set R faults are offset by normal faults (sets N1 and N2) and are interpreted to be pre‐Mesozoic in age, perhaps related to late Paleozoic Alleghanian compression. Normal and normal oblique faults mineralized with chlorite, calcite, and strained quartz (n=73) have been separated into two populations (sets N1, n=49; and N2, n=24) even though these faults are likely of similar age. Host rocks were probably at moderate crustal depths of perhaps 5 km during faulting. Faults of both sets are most likely related to Mesozoic rifting. Tensor configurations indicate that σ1 plunges steeply northwest (N1) and southeast (N2), and σ3 plunges gently, roughly east–west. These faults cut presumably Mesozoic age dikes and are themselves offset by normal oblique faults (set T) and right‐lateral faults (set RL). Strongly deviatoric, near vertical σ1 suggests a thermally driven tectonic regime during the development of normal faulting in New England. Set T (n=25) is composed of normal oblique slip faults mineralized similarly as sets N1 and N2. The plunge of σ1 is 50°N and σ3 plunges gently east. Field relations indicate set T faults document the transition from normal (sets N1 and N2) to strike‐slip faulting regimes (set RL). A compatible sequence of Mesozoic stress fields is suggested de Boer et al. [1988]. North–northeast trending, right‐lateral faults of set RL (n=7) are mineralized with quartz‐limonite‐calcite‐chlorite. Calcite twins are bent and fractured, and quartz grains show minor internal strain, suggesting that these faults developed while host rocks were at relatively shallow crustal levels. The plunge of σ1 is gently northeast and, σ3 plunges gently east–southeast. Seven distinctly mineralized (feldspar‐siderite‐quartzoalcite‐1imonite‐chlorite) gently northwest dipping, thrust faults of set F define the sixth tensor. These faults are cut by essentially vertical, east‐side‐up faults and are assumed to be Mesozoic in age by analogy with similar faults in western Massachusetts.