g

UNITED STATES DEPARTMENT OF THE INTERIOR 
UNITED STATES DEPARTMENT OF THE INTERIOR 

Cecil D. Andrus, Secretary 

BUREAU OF MINES 
This publication has been cataloged as follows: 

Bench, Bernard M 

Methods of determining the orientations of bedrock fracture systems in southwestern Pennsylvania and northern West 

Virginia / by B. M. Bench, W. P. Diamond, and C. M. 

McCulloch. [Washington] : Bureau of Mines, 1977. 

35 p. t maps, graphs ; 26 cm. (Report of investigations - Bureau 

of Mines ; 8217) 

Bibliography: p. 31-32. 

1. hlining geology. 2. Coal mines and mining - Pennsylvania. 

3. Coal mines and mining - West Virginia. I. Diamond, William P., 

joint author. 11. McCulloch, Charles M., joint author, 111. United 

Statcs. Bureau of Mines. IV. Title. V. Series: United Statcs. 

Bureau of Mines. Report of investigations - Bureau of Mines; 8217. 

TN23.U7 no. 8217 622.06173 

U.Su Dept, of the Int. Library 
CONTENTS 

Page 

Abstract . ............................................................... 1 

Introduction ............................................................ 1 

Previous work ........................................................... 3 

Fractures and photolineaments .......................................... 4 

Stereoscopic examination of aerial photographs ...................,...... 6 

Photography ........................................................ 6 

Procedure ......................................................... 7 

Regional structure ............................................... 11 

Ronchi grid inspection of photoindex sheets ............................. 14 

Photography ....................................................... 14 

Procedure ........................................................ 15 

Bedrock joint determination .............................................. 16 

Infrared photolineament determination ................................... 20 

Ronchi grid photolineament determination ................................ 23 

Analysis of directional data .. .......................................... 27 

General discussion of jointing ......................................... 28 

Conclusions ............................................................. 29 

References .......................................................e...... 31 

Appendix ................................................................ 33 

ILLUSTRATIONS 

1 . Map of the project area and the portion underlain by the Pittsburgh 

coalbed .......................................................... 2 . Entrenched meanders, Cross Creek, Avella quadrangle, Washington 

County, Pa ....................................................... 3 . Dunkard Creek and coal mine reservoirs. Blacksville quadrangle. 

Greene County, Pa., and Monongalia County, W . Va., project area . - A, Photographed with panchromatic film in 1958; - B, photographed 

with infrared film in 1972 ....................................... 8 

4 . Photolineaments plotted on Mather 7-1/2-min topographic quadrangle 

map .............................................................. 10 

5 . Rose diagram of photolineaments in Mather quadrangle ............... 11 

6 . Structure map of the area drawn on the base of the Pittsburgh 

coalbed (15) . ..................................................... 12 

7 . Dip slopes and horizontal areas in Morgantown Southquadrangle. West 

Virginia ......................................................... 13 

8 . Diagram of Ronchi grid ............................................. 14 

9 . Lineaments determined by Ronchi grid on photoindex sheet No . 1. 

Washington County. Pa . (17) - ...................................... 16 

10 . Rose diagram of bedrock joints in the Mather quadrangle ............ 17 

11 . Individual rose diagrams of bedrock joints in quadrangles of the 

project area ..................................................... 18 

12 . Composite rose diagram of principal bedrock joint trends ........... 19 

13 . Individual rose diagrams of photolineaments in quadrangles of the 

project area.. ................................................... 21 

14 . Composite rose diagram of principal infrared photolineament trends . 22 
ILLUSTRATIONS - -Continued 

Page 

15. Composite rose diagram of principal Ronchi photoindex sheet trends 23 

16. Maps of the four-county project area showing the eight principal 

Ronchi directions ............................................... 26 

TABLES 

1. Principal bedrock joint trends, in order of dominance ............. 19 

2. Principal infrared photolineament trends, in order of dominance ... 22 

3. Principal Ronchi photoindex trends in order of dominance .......... 24 

4. Principal Ronchi directions on photoindex sheets of the project 

area........................................................... 25 

5. Fundamental or near orthogonal regional systems from directional 

data ............................................................ 27 

A-1. Average bedrock joint trends, by county ........................... 33 

A-2. Average photolineament trends, by county .......................... 34 

A-3. Average Ronchi photoindex sheet lineament trends, by county ....... 35 
METHODS OF DETERMINING THE ORIENTATIONS OF BEDROCK 

FRACTURE SYSTEMS IN SOUTHWESTERN PENNSYLVANIA 

AND NORTHERN WEST VIRGINIA 

by 

B. M. ~ench,' W. P. Diarnond,l and C. M. McCulloch 1 

ABSTRACT 

This Bureau of Mines report describes photolineaments obtained from 

stereoscopic examination of vertical aerial photographs and by the Ronchi 

grating study of aerial photoindex sheets. The photolineaments are compared 

with the trends of oriented fracture systems procured by measuring the compass 

direction of joints in bedrock. The relative reliability of the methods is 

shown, and the results are presented in graphical, tabular, and written form. 

Analyses of field measurements of strikes of bedrock joints in the project area indicate for the most part two intersecting sets of major joints 

oriented N 76" W - N 15" E, and N 57" W - N 27" E. The analyses of lineaments 

determined by stereoscopic examination of aerial photographs show dominant 

trends of lineament zones of weakness to be an average of N 65" W - N 20" E. 

Analysis of lineaments found by Ronchi grid viewing of aerial photoindex 

sheets indicate dominant trends of N 70" W - N 27" E. The three methods give 

similar findings and verify the work of previous authors. 

The Ronchi grid method is a useful guide, but it cannot be substituted 

for the two more painstaking methods. 

INTRODUCTION 

The project includes Washington and Greene Counties and parts of 

Allegheny and Fayet te Counties in southwestern Pennsylvania , and Monongalia 

and Marion Counties and parts of Wetzel, Preston, Taylor, and Harrison 

Counties in northern West Virginia. About 65 pct of the total project area 

is in Pennsylvania, and 35 pct is in West Virginia. This area of about 2,200 

square miles is cwered by thirty-nine 7-1/2-min quadrangles in the general 

rectangular region, 33 miles east to west and 69 miles north to south (fig. 1). 

The entire project is within the Appalachian Plateau province. 

'~eolo~ist. 

All authors are with the Pittsburgh Mining and Safety Research Center, 

Pittsburgh, Pa. 
y 

and the emission 07 methane 

gas (3, 2-89 11). 

The measurements of 

surface joints is a procedure that is sometimes 

applicable in analyzing 

tectonic forces such as 

those of the Appalachian 

orogeny that affected 

various areas and produced 

structural trends. The use FIGURE 1. - Map of the proiect area and the portion of aerial photographs pro- underlain by the Pittsburgh coalbed. vides a supplementary check 

system with a broad overall view. Aerial photographs permit examination of 

inaccessible terrain for lineaments that could be located in the field only by 

great expenditure of time and effort. The interpretation of aerial photographs also has the advantage of being independent of weather conditions. 

2Underlined numbers in parentheses refer to the list of references preceding 

the appendix. 
Anticlinal and synclinal structures in the bedrock of the project area 

have a general trend of N 25O to 30° E. Field measurements of face cleat 

orientations of coal in underground coal mines denote a gradual variation in 

direction from N 76' W in the southern part of the area to N 67O W in the 

northern portion. Butt cleat orientations show a variation from N 17O E in 

the southern part to N 28' E in the northern part of the project. In the 

blocky Pittsburgh coal, the directions of underground room and pillar mining 

commonly follow the butt and face cleat directions to take advantage of the 

natural breaking of the coal. 

The success of mining operations is dependent upon costs. For this reason, the determination of bedrock features that indicate underground 

conditions is often considered unnecessary. The cost of such investigations,. 

however, is minor compared with the benefits derived. 

The cost of data for a particular mining property would only be a small 

part of that required for the present study in the Allegheny Plateau. Here, 

the costs or consulting fees for determining the orientations of bedrock 

fracture systems by the three methods are estimated as follows: 

Method Total cost 

1. Measuring directions of bedrock joints by a team of 2 men, 

2 days in field, and 1 day for tabulation and analysis of 

data per 7-1/2-min quadrangle, $650. Evaluation of 39 

quadrangles in 33 weeks as in this report. 

Stereo study for lineaments on infrared aerial photographs 

by 1 man, including field checking and $110 cost of photo 

coverage per 7-1/2-min quadrangle, $530. Study of 39 

quadrangles in 32 weeks. 

Ronchi evaluation of lineaments on photoindex sheets by 1 

man at rate of an area cwering eight 7-112 min quadrangles per day, including a $40 cost of index sheets 

and covering entire 39 quadrangles in 1 week. 650 

Ronchi inspection of photoindex sheets is helpful for reconnaissance work 

and corroboration, but it cannot replace the stereoscopic study of lineaments. 

The work must be confirmed by bedrock-joint directions in the field or by 

infrared photolineament analysis. 

PREVIOUS WORK 

Results of the study of lineaments in this paper were used in a more 

comprehensive study of the mining geology of the Pittsburgh coalbed (12), and 

the analytical techniques for evaluating the directional data were 

published in Geology (1) and in Bureau of Mines Report of Investigations 8120 

(2). However, space limitations in these papers does not permit the type of 

discussion and explanation for the present purpose of describing and comparing 
the methods in more detail. Although most of the data and illustrations used 

were published previously (L-2, l2) they are included here for convenience. 

Hough (I) published a comprehensive paper on photogeologic techniques for 

mapping rock joints. The area of his investigation included the Morgantm 

15-min quadrangle, the western half of which is within the study area of this 

paper. 

Kent and Pillmore (7) conducted a field and aerial photo study of the 

surface fracture system of the Pittsburgh coalbed area to evaluate the use of 

black-and-white infrared photographs for photolineament surveys and to 

determine the compass orientation of major joint sets. In addition, the study 

included data and geologic features of mine roof failure. Kent (6) made a 

similar study of the surface fracture system of southern Ashland County, 

Ohio, where terrain is similar to that of the project area. 

Lattman (2) , in his work on nomenclature, definition, and techniques , designated fracture traces of less than 1 mile in length as "linears," and 

those more than 1 mile long as "lineaments"; however, in this report all such 

alinements regardless of length are designated lineaments. 

Nickelsen and Hough (l3) made an extensive investigation of jointing in 

the Appalachian Plateau of Pennsylvania. They discussed the orientation and 

origin of joints in sandstone, shale, and coal, and also determined the 

orientations of major joints in shale and of systematic joints in coal. In 

addition, they attempted to classify some differences between their view of 

jointing, joint sets, and joint systems and the views of other authors. The 

work of Nickelsen and Hough is substantiated by a Bureau of Mines report (g) 

that presents new methods of attaining the same results of determining 

directions of oriented fracture systems. 

Roen and Farrel (l5) prepared a structure contour map of the Pittsburgh 

coalbed, southwest Pennsylvania and northern West Virginia. This very important and useful map was constructed on a scale of 1 to 125,000 with a contour 

interval of 100 feet. 

FRACTURES AND PHOTOLINEAME NTS 

Fractures include all types of discontinuity that result from mechanical 

failure in rock. They may be produced by either shear stress or tensile 

stress and include faults, shears, joints and fracture zones. Joints are 

fractures along which there has been no visible movement parallel to the joint 

surface. Many small irregular fractures cutting a mass of rock in a 

relatively restricted area comprise a fracture zone. In coal, joints and 

fractures are termed "cleats" (z) . 

Most rocks are fractured in varying degrees, depending on rock type and 

the nature of the regional and local stresses applied to the rock. Two or 

more principal directions of fracturing are normally present. Hough (2) 

and Kent (5-1) determined that photolineaments are the cumulative eiidence of 

zones of linear weakness accentuated on the surface by erosional processes. 
They have directional trends similar to those of the prominent sets of joints 

in rock outcrops. The recognition of photolineaments and their correlation 

with joint sets is possible because of the combined expression of numerous 

parallel joints that are collectively evident as a line or fracture belt when 

photographs are viewed stereoscopically (6). Straight portions of streams, 

long straight valleys, and right-angle beids of present or former stream 

channels originating from intersecting fractures are included within this 

category; they apparently result from lineament zones that were weakly resistant to erosion along which drainage was concentrated in the initial stages of 

stream flow (6-7). - - 

The larger streams in southwestern Pennsylvania and northern West 

Virginia have been incised or entrenched as much as 150 feet since glacial 

times (g), indicating relatively rapid removal of overburden. Throughout 

uplift of the area, these streams have maintained their courses and meanders 

in places where they were first influenced by fracture systems (fig. 2). 

Precautions were taken during the interpretation to avoid mistaking 

fracture and fault traces caused by valley stress release with structural 

lineaments. Ferguson (&), in his work on flood control and dams containing 

locks for navigation, describes compression faults in valley bottoms and 

tension fractures in the walls. Such fractures are mostly vertical, parallel 

to the strikes of the valleys, and generally of local and limited extent. 

Actual joints are too small to be seen on photographs ; therefore, 

interpretation of trends of structural weakness is based on lineament features 

believed to be related to fracture zones. The passage or presence of water 

in such zones accentuates lineaments that include the following: straight 

parts of streams, right-angle bends in streams and rivers that appear to 

result from the intersection of two joint or fracture zones, lines of trees 

taller than average, alinements of vegetation, dark zones caused by greater 

than normal moisture concentration, fairly straight color-tone differences 

in open ground, lineament depress ions on sides or tops of divides , and 

straight portions of valleys (5, - - 7, - 11). 

Paleogeographic maps (2) indicate that no sediments younger than Permian 

have been deposited in the region. The same tectonic forces that produced 

fractures in sedimentary beds now exposed on the surface are believed to have 

been responsible for the cleats in the underlying coalbeds (11). - 
FIGURE 2. - Entrenched meanders, Cross Creek, Avel la quadrangle, Vlashington County, Pa. 

STEREOSCOPIC EXAMINATION OF AERIAL PHOTOGRAPHS 

Photography 

Two types of black and white film are generally used for aerial photography, panchromatic and infrared. The sensitivity of panchromatic films is 

exceptionally good. This sensitivity insures that the film will respond to 

all wavelengths of visible light, and that all tonal gradation in the original scene will be reproduced. Black-and-white infrared film is receptive 

to reflective infrared radiation in addition to the visible spectrum. 
The infrared film is particularly well suited to the interpretation of 

lineaments related to slight differences in moisture content. Relative moist 

areas such as fracture zones appear dark in the images. Water photographs 

jet black because it absorbs almost all the radiant energy of infrared 

wavelengths (fig. 3). Ultraviolet radiation and blue light are filtered out 

to penetrate haze and to achieve high contrast in black and white tones. 

The cost of black and white infrared aerial photography by private companies 

is nearly four times that of the black and white panchromatic photography 

available from the Soil Conservation Service. However, the superior qualities 

of the infrared for photolineament enhancement and the factors of easier 

interpretation with better results more than justify the cost differential 

by the savings in salaries and time. 

Procedure 

The scale of the aerial photos used in this study is approximately 

1/24,000 (1 inch=2,000 feet), similar to the scale of the 7-1/2-min topographic sheets on which the data were plotted. Photographs of individual 

quadrangles were assembled and cataloged in their proper positions. Approximately 21 photographs cover the area of one 7-1/2-min quadrangle. 

Features identified as lineaments were marked on the photographs with 

colored pencils. Black was used for straight segments of streams and 

valleys believed to have originated from differential erosion along fracture 

zones. These were by far the most common lineaments observed. Less common 

features, such as right-angle bends in stream channels, soil tone differences, 

linear depressions, and vegetational indicators were marked in orange. The 

last three features are often obscured by the cultural development, coal mine 

operations, fences, powerlines, and pipelines, prevalent in the area. 

The individual lineaments marked on the infrared photographs were 

transferred to 7-1/2-min topographic quadrangle maps (fig. 4) and the strike 

of each lineament was measured with a protractor and recorded. The 

individual measurements for each quadrangle were next plotted on a rose 

diagram (fig. 5) to be used in the analysis of the fundamental or orthogonal 

directional systems. 
FIGURE 3. - Dunkard Creek and coal mine reservoirs, Blacksville quadrangle, Greene County, 

Pa., and Monongalia County, W. Va., proiect area. A, Photographed with panchromatic film in 1958, 
FIGURE 3. - Dunkard Creek and coal mine reservoirs, Blacksville quadrangle, Greene County, 

Pa., and Monongalia County, W, Va., proiect area. B, Photographed with infrared film in 1972. 

390 total readings 0 10 

Frequency of readings 

FIGURE 5. - Rose diagram of photolineaments in Mather quadrangle. 

1 Regional Structure 

In addition to lineaments, an impression of geologic structure was 

obtained from the stereoscopic examination of the aerial photographs. 

Structure in the study area shown in figure 6 is characterized by a broad 

basin, containing widely spaced, gently dipping anticlines and sync lines. 

Dips are generally less than lo or about 100 feet per mile. Beds having 

greater dip than this occur only on the west flank of the Chestnut Ridge 

antic line in Rivesvil le , Morgantown North, Morgantown South, and Gladesvi lie 

quadrangles. Actual rock exposures in the area are scarce because of forest 

and soil cover. The hogback and cuesta topographic surface expression of the 

structure on the west flank of the Chestnut Ridge anticline, however, is 

clearly evident by the dip slopes recognized on the photographs (fig. 7). 

Throughout most of the study area, a general impression of low dip 

attributed to nearly horizontal beds is interpreted from sedimentary layers 

observed as tonal contrasts in fields along hillsides and ridges. Individual 

beds with slightly different contents of water and mineral matter register on 

infrared film in varying shades of gray. Distinct bands of varying intensity 

FIGURE 7. - Dip slopes and horizontal areas in Morgantown South quadrangle, West Virginia. 
of Washington and Greene 

Counties, Pa. , and Monongalia and Marion Counties, 

W. Va. Photoindex sheets 

are composed of individual 

photos, usually at a scale 

of 1 inch=l mile, joined 

together at their edges. 

The photoindex sheets 

are usually made by shingling or overlapping aerial -. - 

photographs along or across 

flight lines, and the 

assembled index is then 

photographically reduced to 

an appropriate scale. The 

photoindex sheets of this 

B study were constructed for 

the U.S. Department of FIGURE 8. - Diagram of Ronchi grid. Enhancement of a Agriculture Cmodity set of photolineaments takes place when Stabilization Service from 

the Ronchi grid lines are perpendicular to photographs of scale 

the direction of the photolineaments. The 1:20,000 and reduced to a 

compass direction of line A-0 will show scale of 1/62,500 (17). - 

the bearing of the photolineament set. 
Procedure 

Photoindex sheets are generally attached to a wall or other flat vertical 

surface for convenience in viewing. Lineament trends are ascertained by 

slowly rotating the Ronchi grid while viewing an index sheet from a distance 

of 2 to 10 feet. The grid is best held inside the near focus of the 

eyes, 1 to 2 inches depending on the viewer's vision and personal preference. 

The enhancement of a set of lineament trends occurs when the lines of the 

Ronchi grid are perpendicular to the lineaments on the index sheets. The 

lineament images seen through the Ronchi grid differ from the narrow and 

discontinuous scattered lineaments seen with a stereoscope. The Ronchi images 

tend to fill the index sheet with relatively wide bands similar to a herringbone pattern. 

A reconnaissance viewing of a sheet is made with the Ronchi grid to 

determine the number and general strike of lineament trends and the relative 

dominance of each trend based on image strength. A close measurement 

of the strike of each trend is made after rotating the grid back and forth 

to define the most prominent or distinct orientation of the intensified 

lineament image. A line is drawn on the photoindex sheet to indicate the 

strike of the trend and is measured with a protractor and recorded along with 

its relative dominance (fig. 9). 

True lineaments create diffraction images only in the direction of the 

lineament itself, but buildings, trees, and all other fairly compact objects 

can f orm a linements in any direction the Ronchi is rotated. Roads , pipeline , and powerline clearings commonly give false lineaments that produce erroneous 

data if not recognized, or may enhance or strengthen valid trends if they are 

nearly parallel to a true one. Of particular concern are the north-south and 

east-west images formed by the edges of the individual photographs comprising 

the index sheets. These false lineaments also reinforce natural lineaments 

actually occurring in the same directions. Careful examination of the photographs and index sheets without the Ronchi grid can eliminate most other 

erroneous lineament features. True lineaments, both single or composites of 

many individual parallel features , generally produce more lengthy and stronger 

images than those produced by manmade objects. 
FIGURE 9. - Lineaments determined by Ronchi grid on photoindex sheet NO. 1, Washington 

County, Pa. (l7). 

BEDROCK JOINT DETERMINATION 

Joints in bedrock were measured in the field and corrected to true north 

with a Brunton compass1 in the thirty-nine 7-1/2-min quadrangles of the project 

area. A minimum of 100 joint readings were taken per quadrangle with an 

average of 120 readings for each quadrangle. No more than 10 readings were 

made at a single outcrop. Rock types and quality of joints were noted at 

every exposure. 

The data from each quadrangle were plotted individually on rose diagrams 

as in figure 10 to evaluate the principal directional trends. Figure 11 

shows the rose diagrams of the bedrock joint readings from the individual 

quadrangles assembled in their proper geographic position. From these data, 

a composite rose diagram (fig. 12) of bedrock joint trends for the entire 

study area was constructed by plotting only the dominant trends from each 
101 total readings 

Frequency 

- 

of readings 

FIGURE 10. - Rose diagram of bedrock ioints in the Mather quadrangle. 

individual quadrangle on a single rose plot. Table A-1 in the present paper 

gives the averages of the bedrock joint orientations by county.3 

The different trends are designated by numbers according to their divergence from north to the northwest, and by their divergence from north to the 

northeast. Trends in the same vertical column of a group correspond or are 

correlative through the six counties. Where blank spaces appear, no corresponding trends were found. The order of dominance of the trends is designated 

by superscipts I, 11, 111, and IV. 

Peaks for the bedrock joint and infrared photolineament methods were 

defined by comparing the number of readings comprising each high point on a 

rose diagram with the number of readings in the adjacent 5O interval. A 

decline of one-third the number of readings comprising a 5" interval high 

point was used to define the limits of an individual peak. 

3~he bedrock joint readings from individual quadrangles are shown in appendix B, pages 66 to 68, in Bureau of Mines RI 8093. They are listed according to counties in rows of quadrangles from north to south, figure 30, 

page 40. Separate tables contain the readings that are to the west of 

north and those to the east of north. 
The first 5O interval on 

each side containing less than 

,,, 

two-thirds of the number comprising the high point was not 

included within the peak. However, if the first 5' interval 

to decline one-third the number 

of readings of the high point is 

above the line of the average 

number of readings, and the next 

adjacent 5" interval declines by 

an additional one-third , then 

the first 5O interval is considered as part of the peak. 

WASHINGTON COUNTY 

To be included in the 

analysis of directional trends , the peaks as defined must 

I 

I Cloysville Prosperity Amity Ellsworth Co (1) extend above the line of the 

/09 -(/~>~-.-f//, /2 average number of readings, and - ----; 4 )r A/ GREENE COUNTY (2) be composed of at least I 4 pct of the total number of 

readings. A difference of 

10 pct in the number of readings 

was considered sufficient to 

assign different orders of 

dominance. The most dominant 

peak was assigned the first 

I New Freeport Holbrook Ook Forest Gorords Fort Mosontown 

/26 

order of dominance, and the next 

/3 7 /30 /09 99 most dominant was second order, 

-- --- Pa -- etc. 

Morgontown Figure 12 illustrates the Hundred ' Wodestown Blocksville Osoge North 

WETZEL . /56 d, //7 /43 /2/ /08 presence of three regional 

COUNTY \ - - -- - - MONONGAL IA trends in the northwest quadrant COUNTY and four in the northeast 

quadrant (table 1). The number 

South directly above the directional Glover Gop Monnington Gront Town Rivesville 

//5 /87 300 /44\ I28 trend in table 1 is the order of 

MARION COUNTY dominance of that measurement 

in relation to the others in the 

8 &- 4 d same group. The orders of 

~olloce 65 Lhi:n ~~q~&;rm;;~E$ode~ville - /09 dominance assigned to the trends 

are determined by the number of 

HARRISON COUNTY 0 

w 

7 ml)es measurements comprising the 

143 -Indicates total readings peaks that correspond to the 

0 10 kilometers 

Scale trends on the composite rose diagram. Two orientations, N 57O W 

FIGURE 11. - Individual rose diagrams of bedrock and N 7(j0 w in table 1 under the 

joints in quadrangles of the project West I group, show equally 

area, strong directional trends. 
207 read ings total 

readings 

(5.8) 

Frequency of readings 

FIGURE 12. - Composite rose diagram of principal bedrock ioint trends. 

TABLE 1. - Principal bedrock ioint trends. in order 

of dominance 

The principal directional trends listed in table 1 form six fundamental 

or near orthogonal joint systems, composed of two trends each that are near 

90" to each other as follows : 

Sys tems 

1. N 57" WI and N 27" E" (84" separation). 

West group 

2. N 57O W' and N 15" E' (72" separation). 

3. N 57" W' and N 37" E' ' ' (94" separation). 

I 

N 57" W 

N 76O W 

East group 

4. N 76" W' and N 15" EI (91° separation). 

111 

N 34" W 

- 

I 

N 15" E 

- 

5. N76"w1 andN27"~" (103"separation). 

6. N 34O w'" and N 47" E'" (81" separation). 

NOTE.--The superscripts in Roman numerals indicate the order of dominance. 

IV 

N 47" E o 

I1 

N 27" E o 

I11 

N 37" E 

- 
Two bedrock joint systems (2 and 4) are composed only of joint sets of 

the first order of dominance and both systems contain the N 15O E' set. 

System 4, with a 91° separation, more closely approaches the fundamental or 

near orthogonal system's 90° separation than does system 2 with a 72O 

separation. 

System 5 also contains the N 76O W' bedrock set but the eastward component of this system is less dominant than that of system 4, and its divergence 

from an ideal orthogonal system is greater. System 4 is thus considered the 

most dominant system containing the N 15 E' and N 76O W' sets. 

The N 15O E directional trend is given the first order of dominance 

because it is composed of 19 readings compared with 15 readings for N 27O E. 

In the rose diagram (fig. 12) , the N 27O E directional trend, which only spans 

a 5O interval, appears more prominent because of its length and the flaring at 

the top; however, the N 15O E direction spans a lo0 interval and actually contains more readings. The average number of readings per 5O interval is 5.8. 

Systems 1 and 3 contain a westward bedrock set (N 57O W' ) of equal dominance to that of N 76O W' in system 4. Although both systems have nearly 

equal divergence from an ideal orthogonal orientation, system 1 with a higher 

order of dominance for the eastward set (N 27O El ' ) is the most dominant 

system containing the N 57O W' set. Systems 1 and 4 are therefore determined 

to be the most dominant bedrock systems that can be paired from the data in 

table 1. 

The eastward trends of systems 1 and 4 closely parallel the strike of the 

major structural axes of the area, and the trends to the west are nearly petpendicular to the axes. These systems are thought to be directly related to 

the regional structural deformation. 

The sixth bedrock joint system (N 34O W' ' - N 47" E' " ) may also be 

related to the regional structure, even though composed of sets of the third 

and fourth order of dominance and not oriented parallel to the cleat directions. This system is oriented at approximately 45O to the N 76O W' - N 15' E' 

system, which is within the theoretical angle of shears to the dominant trends. 

INFRARED PHOTOLINEAMENT DETERMINATION 

Rose diagrams were prepared for each of the 39 quadrangles using the data 

obtained from examination of infrared photographs. The individual rose diagrams are positioned in their proper geographic location within the study area 

in figure 13. The dominant trends of all the quadranges areplottedona single 

compositerosediagram (fig. 14). Directional trends arrangedbyrow and corresponding counties from north to south are given in the appendix, table A-2. 

Numbered trends are separated into west and east directional groups by their 

increasing divergence from north and not by their order of dominance. Trends 

within the same vertical column of a group are approximately correlative, 

being close to the same orientation. 
- \ ALLEGHENY \yTY TIER \ 

I ', 

Avel lo Midwoy Cononsburg Bridgeville \- i /TI 188 N4 55 

ll*~*~%:!!~

West Middletown Washington West Woshingtw, Eust Hackctt Monongo helo 

I ~lo~sv~lle Prosperity Amity 1 Ellsworth ~olifornio/ 

450 -428 - - 298, 

GREENE COUNTY 

- - 

Wind Ridge Rogersville Woynesburg Mother ~orrnichoels 1 854 738 521 390 279\ 

I 

I 

I ~ew?k~~ort 1 Holbrook I Oo>Ft I Gorordr fort I ~~yyn I I 607 494 4/6 

I Hundred \ 1 Wodestown I Blocksville I Osage I North 

WETZEL 7oz-,x_ 673 1 143 

COUNTY - - - MONONGALIA 

' COUNTY 

Wol loce 

724 , 423 '4,08--* \39/-/ 384 

HARRISON COUNTY 0 7 miles 

495 -Indicates total readings 

w 

0 10 kilometers 

Scale 

FIGURE 13. - Individual rose diagrams of photolineaments 

in quadrangles of the proiect area. 
Average number of re 

per 5O interval (6.5) 

233 readings total 

Frequency of readings 

ad ings 

FIGURE 14. - Composite rose diagram of principa 1 infrared photo! ineament trends. 

Figure 14 indicates the presence of five regional photolineament trends 

in the northwest quadrant and three in the northeast quadrant. The order of 

dominance 05 these trends is presented in table 2. 

TABLE 2. - Principal infrared photolineament trends, in order 

of dominance 

Individual photolineament trends are paired into five fundamental or near 

orthogonal infrared photolineament systems. 

Sys tems 

1. N 65" W' and N 20" E' (85" separation). 

West group 

2. N 79" W' ' and N 20" El (99" separation). 

3. N 79" w'I' and N 01" E" (80" separation). 

4. N 25" WI ' aand N 75" El ' (100" separation). 

5. N 13" Wv and N 75" E' (88" separation). 

NOTE .--Superscripts in Roman numerals indicate order of dominance. 

I 

I 

N 65" W - 

I1 

N 25" W 

- 

East group 

I 

N 20" E 

- 

I11 

N 79" W 

N 40" W 

I1 

N 01" E 

- 

v 

N 13" W o 

I11 

N 75" E o 
The first infrared photolineament system (N 65" W' - N 20" E' ) is composed of the most dominant westerly set and the most dominant easterly set. 

This system is quite similar in orientation to the most dominant systems (1 

and 4) paired in the bedrock joint analysis. The N 20' E' set, if not paired 

with N 65O W' , could be paired with N 79" WI ' (system 2) to approximate one 

of the dominant bedrock joint systems, but this system contains one set of the 

third order and has a larger divergence from 90" than system 1. The N 79' w"' 

set can also be paired with N 01° E' ' (system 3) for an 80" separation. 

System 3 is fairly close to one of the most dominant bedrock joint systems 

(system 4); however, it contains one set of the third order of dominance. 

Systems 4 and 5 are within the theoretical limits for shears associated 

with the dominant systems. Both of these are composed of at least one set of 

third or lower order of dominance. System 1 is judged to be the most dominant 

photolineament sys tern. No other photolineament sys tem is considered to be of 

similar dominance. 

RONCHI GRID PHOTOLINEAMENT DETERMINATION 

Principal directional trends as interpreted from the 13 individual photoindex sheets of the area are plotted in a composite rose diagram (fig. 15). 

104 readings total - 

Frequency of readings 

FIGURE 15. - Composite rose diagram of principal Ronchi ~hotoindex sheet trends. 
Directional databy county fromnorthto south is givenin the appendix, table A-3. 

Numbered trends are separated into west and east directional groups by their 

increasing divergence from north and not by their order of dominance. Trends 

within the same vertical column of a group are assumed correlative. 

The composite rose diagram (fig. 15) shows four directional trends to the 

west and four to the east. Although the order of dominance of the directional 

trends does not stand out clearly in figure 15, major trends were established 

(table 3), based on the strength of the alinements viewed through the Ronchi 

grid. 

TABLE 3. - Principal Ronchi photoindex trends in order of dominance 

The 13 photoindex sheets used in the project cover Washington and Greene 

Counties , Pa. , and Monongalia and Marion Counties , W. Va. Eight trends were 

measured on each sheet. The individual readings are indicated on figure 16 

and in table 4. There are 13 readings for each general trend, and since all 

have the same number of readings, some reliance must be placed on the visual 

strength of the image. The general directional trends of N 70" W and N 27" E 

are very pronounced in viewing with the Ronchi grid. 

The principal directional trends delineated by the Ronchi grid are listed 

in the appendix, table A-3, and can be paired into five possible fundamental 

or near orthogonal sys tems : 

West group 

Svs tems 

East group 

1. N 70" W' - N 27" E' (97" separation). 

2. N 70" W' - N 12" E' ' (82" separation). 

IV 

N 09" W 

I 

N 27" E 

I 

N 70" W 

3. N 23" WI - N 77" EI (100' separation). 

4. N 44" W" - N 55' Elv (99" separation). 

5. N 09" wIV - N 77" El' (86" separation). 

I1 

N 77" E 

I1 

N 44' W 

NOTE.--Superscripts in Roman numerals indicate order of dominance. 

I11 

N 23' W 

The most dominant westerly trend, N 70" W' , can be paired with either 

N 27" E' , the most dominant easterly trend, or with N 12" EI ' to approximate 

nearly orthognal systems. The first system is by far the most dominant of the 

two. The last three Ronchi systems are not nearly as dominant as system 1, 

but they have components within the limits of the theoretical angles for 

shears. Ronchi photoindex system 1 is quite similar in orientation to the two 

bedrock systems and also to the single infrared photolineament system judged 

to be the most dominant. 

I11 

N 12' E 

IV 

N 55" E 
TABLE 4. - Principal Ronchi directions on photoindex sheets 

of the project area 

East 

1 I 2 I 3 I 4 

West 

1 

WASHINGTON COUNTY 

2 3 4 

Sheet: 

1.. .. .. . ... 2.. .. .. .. .. 3... .. .. ... 4 .......... 

5. .. .. .. ... Degrees 

separation.. 

Directional 

mean ........ 

N 45" W 

N 43" W 

N 44" W 

N 45" W 

N 47" W 

4 

N 45" WAN 

N 7" W 

N 10" W 

N 13" W 

N 9"W 

N 10" W 

6 

N 10°W 

GREE NE COUNTY 

N 19" W 

N 24" W 

N 20" W 

N 28" W 

N 27" W 

9 

N 24" W 

N 67" W 

N 67" W 

N 68O W 

N 70" W 

N 77" W 

10 

70" W 

Sheet : 

1.. .. .. .... 2 .......... 

3... . . . .. .. 4.. .. .. .. .. Degrees 

separation.. 

Directional 

mean.. .... .. 

N 23" E 

N 23" E 

N 18O E 

N 17" E 

N 12" E 

I1 

N 19" E 

N 7" W 

N 12" W 

N 9" W 

N 5O W 

7 

N 8" W 

MONONGALU COUNTY 

N 30" E 

N 32" E 

N 27" E 

N 34" E 

N 27" E 

7 

N 30°E 

N 25" W 

N 23" W 

N 20" W 

N 23" W 

5 

N 23" W 

N 51" E 

N 52" E 

N 49" E 

N 50" E 

N 53" E 

Sheet : 

1 .... .. .. .. 2.. .... .... Degrees 

separation.. 

Directional 

mean.... .... 

N 72" E 

N 74" E 

N 70" E 

N 77" E 

N 73" E 

N 47" W 

N 43" W 

N 42" W 

N 44" W 

5 

N 42" W 

N 79" E 

N 81" E 

2 

N 80" E 

N lgO E 

N 26" E 

7 

N 23" E 

MARION COUNTY 

I 7 

N 51° E N 73"E 

N 28" E 

N 24" E 

N 21" E 

N 26" E 

7 

N 25O E 

N 5" E 

N 10" E 

5 

N 8" E 

N 8" W 

N 7" W 

1 

N 8" W 

N 42" W 

N 43" W 

1 

N 43" W 

N 60" E 

N 56" E 

4 

N 58" E 

Sheet: 

1.. .. .. .... 2 .-........ 

Degrees 

separation.. 

Directional 

mean.. .. .. .. 

N 68" W 

N 70°W 

N 70" W 

N 67" W 

3 

N 69" W 

N 20" W 

N 23" W 

3 

N 22" W 

N 69" W 

N 70" W 

1 

N 70" W 

N 14" E 

N 10" E 

N 7" E 

N 12" E 

7 

N 11" E 

N 58" E 

N 56" E 

N 57" E 

N 53" E 

5 

N 56' E 

N 81" E 

N 75" E 

N 77" E 

N 82" E 

7 

N 79" E 

N 8" W 

N 

1 

N 8" W 

OVERALL 

N 72O W 

1 

N 73O W 

N 28" W 

8 

N 24" W 

7 

N 77"E 

N 4" E 

3 

N 6," E 

N 42" W 

7°WN200WN440WN730WN 

2 

N 43" W 

7 

N 55"E 

Degrees 

separation 

between 

counties.. . . Directional 

mean ........ 

N 19" E 

2 

N 20' E 

2 

N 23"W 

, 

2 

N gOW 

N 57" E 

7°EN210EN590EN770E 

2 

N 58" E 

N 78" E 

1 

N 78" E 

10 

N 27"E 

2 

N44"W 

3 

N 70°W 

I 

13 

N 12"E 
\. 

Direction range 19' 

H~gh N 23 E Low N 4 E 

Directlon range 15' 

H1gh N 34 E 

Low N9E 

- , 

-%- 

Direction ronae I lo 

High ~6d E 

Low N 49 E 

Direct~on range 12' 

H~gh N 82 E 

Low N 70 E 

FIGURE 16, - Maps of the four-county proiect area showing the eight principal Ronchi 

directions. 

To obtain a pictorial view of the trends of the eight Ronchi alinements, 

the directions were plotted on small maps of a four-county area covering the 

principal part of the project (fig. 16). The angles and their directions are 

indicated at the center of the photoindex sheets in each county. The highest 

and lowest azimuths are underlined. On these maps, it is seen that the directions of the upper left and the two lower left rotate slightly clockwise from 

south to north in agreement with the butt cleat, joint, and structural axis 

directions. 
ANALYSIS OF DIRECTIONAL DATA 

As many as eight directional trends were established by the various techniques analyzed. Analysis was facilitated and made more meaningful by pairing 

the west and east trends into all possible combinations of potential fundamental or near orthogonal systems (two trends at 90" to each other). The fundamental or near-orthogonal systems obtained for each technique are listed in 

table 5. 

TABLE 5. - Fundamental or near-orthogonal regional systems 

from directional data 

Data source 

Bedrock joints .................... 

Photolineaments (IR photographs). . 

groups (west and east) for each data source. 

Orientation 

N 57" W' N 27" E' ' 

N 57" W' N 15" E' 

N 57" W' N 37" E'" 

N 76" W' N 15" E' 

N 76" W' N 27" E" 

N 34" W" ' N 47" E' 

System 

1 

2 

3 

4 

5 

6 

Ronchi photolineaments (photoindex 

sheets). ......................... 

Joints in the bedrock are believed to have resulted from the tectonic 

stresses and subsequent stress adjustments produced during the erosion and 

unloading that effected the southwestern Pennsylvania and northern West 

Degrees of 

separation 

84 

72 

94 

9 1 

103 

81 

1 

2 

3 

4 

5 

Virginia area, according to McCulloch and Nickelsen (11-13). Two fundamental 

or near orthogonal systems of joints, N 76" W' - N 15"Erand N 57" W' - 

NOTE.--Superscripts indicate the order of dominance within the directional 

1 

2 

3 

4 

5 

N 27" E' ' composed of the most dominant trends to the west and to the east, 

are the bedrock expression of the principal trends and possibly of structural 

weakness. The bedrock joint data were then compared with the data derived 

from the photolineament and Ronchi grid methods. 

N 65" W' N 20" E' 

N 79" W" ' N 20" E' 

N79"~"' NOlOE" 

N 25" W' ' N 75" E' ' 

N 13" wV N 75" E" ' 

In the analysis of both the infrared and Ronchi photolineaments , several 

systems (1, 2, and 3 of the infrared and 1 and 2 of the Ronchi) partially 

85 

99 

80 

100 

88 

N 70" W' N 27" E' 

N 70" W' N 12" E" ' 

N23"W"' N77"E" 

N44"W1' N55"EIV 

N 09" w'" N 77" E" 

correlate with the two most dominant bedrock joint systems (1 and 4). With 

97 

82 

100 

99 

86 

both the infrared photo and Ronchi photolineament methods, one each of the 

correlative systems (N 65" W' - N 20" E' , and N 70" W' - N 27" E') are composed of sets only of the first order, and the other systems are composed of 
at least one set as low as third-order of dominance. All infrared and Ronchi 

photolineament systems that do not have similar orientations to the dominant 

bedrock joint system are composed of at least one set containing a third-order 

dominance. 

Such observations can be used to formulate a set of procedures to be used 

in estimating the dominant trends of structural weakness from photolineament 

data. The procedure is (1) determine the relative dominance of all photolinear trends, (2) pair the trends into all fairly close combinations of 

fundamental or near orthogonal systems, and (3) select the system or systems 

composed of one set which is the most dominant (first order) and the other set 

which is of the first or second order, as the most likely estimate of the 

area's dominant trends of structural weakness. 

Utilizing the procedures proposed and the data of this study, system 1 of 

the infrared photolineament and system 1 of the Ronchi photolineament systems 

are correlative with the two established dominant joint systems 1 and 4, and 

are thereby accepted as estimators of directions of structural weakness. In 

each case, the remaining systems are not used because of lack of dominance. 

The exclusion of the other correlative lineament systems is not considered 

particularly objectionable in this example since the two dominant bedrock 

joint systems are separated by less than 20°. Bedrock joint systems 1 and 4 

listed on table 1 have a separation of lgO in the westerly direction (N 57O W 

to N 76O W) and 12O in the easterly direction (N 27O E to N 15O E). 

Systems 2 and 3 of the infrared photolineaments , N 7g0 W' ' ' - N 20° E' 

and N 7g0 W' 'I - N 01° E' ' , and system 2 of Ronchi photolineaments, N 70° W' - 

N 12O El", correlate moderately well with system 4, N 76O W1 - N 15O El of the 

bedrock joints, but cannot be used as estimators because one of the sets in 

each case has a third order of dominance. It is important to note that only 

photolineament systems that are closely correlative with the two dominant 

bedrock joint systems are chosen as estimators, whereas those not correlative 

are excluded because they contain orders luwer than I or 11. 

Even though the analysis of the Ronchi phot olineaments correctly 

estimates one of the dominant joint systems under the proposed procedure, the 

confidence in this method is luwer than that of the infrared photoanalysis. 

This is due to the necessity of partly determining the dominancy of Ronchi 

trends based on a strictly visual impression of image "strength" as opposed to 

a more analytical approach for the other technique. 

GENERAL DISCUSSION OF JOINTING 

Although jointing occurs in many types of rock, there is some question as 

to whether the greatest number of joints in certain azimuths are direct and 

simple indications of structural weakness. The types of rock and the forces 

that act upon them determine the joint systems that evolve. A massive sandstone, siltstone, or arenaceous shale may have characteristic directions at 

regular intervals. A joint system may have sets that were developed at varying 

times under different conditions. A sedimentary rock under compression by 

overburden can develop a set while consolidating. A joint set may form by 

release of pressure during erosion, and at other times through tensional 
movement. In folded rocks, the joint pattern can be related to stress 

directions in a very irregular manner. 

The configuration of folds, character of bedding and lithology, and the 

dip of beds affect the spacing, orientation, and number of joints. Drainage 

development also influences the types, number, and proportions of lineaments 

as well as the size and manner in which outcrops are exposed. Furthermore, 

it is conceivable that some well-jointed rocks are so soft and friable that 

no exposures remain to measure. 

The practice of combining joint trends of various directions from minor, 

widely scattered outcrops, formed at different times in various types of rocks, 

may include some intrinsic error, especially when considering effects of local 

conditions and limited areas of weakness within regional zones. Some geologists believe that joints form in the process of lithification and compaction 

and are not dependent orogenic forces. However, mountain building and directional tectonic forces such as provided by the Appalachian orogeny are believed 

to have had a part in the formation of major joints sets in the study area. 

Pennsylvanian and Permian sediments account for practically all of the 

bedrock in the project area; sandstones and siltstones are the most common. 

The procedure in taking joint measurements was first to make a reconnaissance 

by automobile of the quadrangle to be investigated with the help of available 

geological and topographic maps, noting outcrops, access roads, and routes to 

be taken. The orientation of every joint was measured regardless of prominence and without selectivity in direction. For an overall evaluation, it was 

decided to include all joint directions; perhaps in this way, the most pronounced trends would emerge. This is seemingly what happened, even with the 

disparities and complexities of joint origin and occurrence. The results 

after tabulation and analysis indicate trends of structural weakness that 

appear to be dependable in the area of the Allegheny Plateau. 

CONCLUSIONS 

The three methods described in this paper produced essentially similar 

results, and these findings are substantially the same as those obtained by 

Nickelsen and Hough (13). Data on cleat directions in Bureau of Mines 

RI 8093 (12) - and thatTetermined by Nickelsen and Hough (13) are also in close 

agreement. The principal bedrock joints and zones of weaGess in the area of 

the Pittsburgh coalbed are found to be almost parallel to the cleats in the coalbeds. It has also been observed that directions of coal cleats are more 

uniform and indicate less directional diversity than joint directions in 

surrounding rocks. 

Zones of structural weakness in the earth's crust may be the cause of 

roof falls during underground mining of coal. Where these zones are observable as fractures in bedrock exposures, their directions can be measured 

directly in the field, or if difficult field conditions exist, directions can 

be estimated by the recognition of lineaments through stereoscopic examination 

of aerial photographs. 
The strikes of joints occurring in bedrock were measured throughout the project area in southwestern Pennsylvania and northwestern 

West Virginia to compare with photogeologic methods for coal mining investigations. The procedure formulated for estimating zones of structural weakness 

were to (1) define the outstanding photolineament trends, (2) pair the trends 

into combinations of fundamental or near orthogonal systems (two trends, at 

near 90" to each other ) , and (3) select as the estimator of structural weakness the system or systems composed of one trend that is the most dominant and 

the other trend that is the first or second most dominant. 

The measurement and analysis of bedrock joints in the field is believed 

to be the most direct and reliable method for determining dominant trends of 

structural weakness. Photolineament analysis through steroscopic viewing of 

infrared photographs is a useful substitute or complementary method, especially when field work is difficult owing to weather conditions, rugged terrain, lack of outcrops, or unavailability of field personnel. 

The Ronchi grid examination of photoindex sheets closely estimated the 

dominant trends of structural weakness. However, less confidence is placed in 

this method owing to the necessity of determining dominancy of trends 

by a visual impression of image "strength." The primary function of the 

Ronchi method is for relatively fast and inexpensive reconnaissance on a 

regional basis. It is desirable for use in conjunction with the analysis of 

bedrock joint and photolineament data for comprehensive information. No one 

method is infallible; the three complement each other. 
REFERENCES 

1. Diamond, W. P., C. M. McCulloch, and B. M. Bench. Estimation of Coal 

Cleat Orientation Using Surface Joint and Photolinear Analysis. 

Geology, v. 3, No. 12, 1975, pp. 687-690. 

2. . Use of Surface Joint and Photolinear Data for Predicting Subsurface Coal Cleat Orientation. BuMines RI 8120, 1976, 13 pp. 

3. Elder, C. H., P. W. Jeran, and D. A. Keck. Geologic Structure Analysis 

Using Radar Imagery of the Coal Mining Area of Buchanan County, Va. 

BuMines RI 7869, 1974, 29 pp. 

4. Ferguson, H. F. Valley Stress Release in the Allegheny Plateau. Assoc. 

Eng. Geol., v. 4, No. 1, 1967, pp. 63-71. 

5. Hough, V. D. Photogeologic Techniques Applied to the Mapping of Rock 

Joints. W. Va . Geol . and Econ. Survey, RI 19, 1960, 21 pp. 

6. Kent, Be H. Photofield Study of the Surface Fracture System of Southern 

Ashland County, Ohio. U.S. Geol. Survey, 1971, 13 pp.; available for 

consultation at Bureau of Mines Mining and Safety Research Center, 

Pittsburgh, Pa. 

7. Kent, B. H. , and C . L. Pillmore. Photofie ld Study of the Surf ace Fracture System of Southwestern Pennsylvania and Northern West Virginia. 

U.S. Geol. Survey, 1973, 19 pp. ; available for consultation at Bureau 

of Mines Mining and Safety Research Center, Pittsburgh, Pa. 

8. Kissell, F. N. The Methane Migration and Storage Characteristics of the 

Pittsburgh, Pocahontas No. 3, and Oklahoma Hartshorne Coalbeds. 

BuMines RI 7667, 1972, 22 pp. 

9. Lattman, L. H. Technique of Mapping Geologic Fracture Traces and 

Lineaments on Aerial Photographs. Photogranmetric Eng. , v. 24, No. 4, 

1958, pp. 568-576. 

10. McCulloch, C. M., and M. Deul. Geologic Factors Causing Roof Instability 

and Methane Emission Problems. BuMines RI 7769, 1973, 25 pp. 

11. McCUI-I-OC~, C. M., M. Deul, and P. W. Jeran. Cleat in Bituminous Coalbeds. 

BuMines RI 7910, 1973, 25 pp. 

12. McCulloch, C. M., W. P. Diamond, B. M. Bench, and M. Deul. Selected 

Geologic Factors Affecting Mining of the Pittsburgh Coalbed. BuMines 

RI 8093, 1975, 72 pp. 

13. Nicke lsen , R. P. , and V. D. Hough. Jointing in the Appalachian Plateau 

of Pennsylvania. Geol. Soc. Am. Bull. , v. 78, 1967, pp. 609-630. 
14. Pohn, H. A. Analysis of Images and Photographs by a Ronchi Grating. 

Remote Sensor Application Studies Progress Report, July 1, 1968 to 

June 30, 1969. U.S. Geological Survey, 1970, 9 pp. ; available from 

National Technical Information Service, Springfield, Va. , PB 197-101. 

15. Roen, J. B., and D. E. Farrel. Structure Contour Map of the Pittsburgh 

Coalbed, Southwest Pennsylvania and Northern West Virginia. U.S . Geol. 

Survey, 1972; available for consultation at Bureau of Mines Mining and 

Safety Research Center, Pittsburgh, Pa. 

16. Schubert , C. Atlas of Paleogeographic Maps of North America. John Wiley 

& Sons , Inc . , New York , 1955, 177 pp . 

17. U.S. Department of Agriculture Cmodity Stabilization Service. 

Washington County, Pa. Sheet 1. County Symbol APT, Scale 1:20,000, 

Graphic Scale 1 inch = 1 mile. Woltz Studios, Inc., Des Moines, Iowa, 

1958 

18. Wagner, W. R. , L. Heyman, R. E. Gray, D. J. Belz, R. Lund, A. S. Cate , and C. D. Edgerton. Geology of the Pittsburgh Area. Pa. Geol. Survey 

Rept . G-59, 1970, 144 pp. 
APPENDIX 

TABLE A-1. - Average bedrock joint trends, by county 

Groups 

1 I 2 1 3 4 I 5 1 6 I 7 

County 

ULAU I 

from north and not by their order of dominance. Trends in the same vertical column 

assumed correlative through the counties. 

Tier 

WE ST 

- 

Marion and Harrison.. 

Directional mean.. 

NOTE.--Numbered trends are arranged within the 2 directional groups (west and east) by inc

N 46" E 

N 49" E 

N53"~ - 

8 

- 

FACT 

N 29" E 

N 28'E 

N 27" E 

N 25" E 

N 19" E 

N 22" E 

- 

- 

N 63" 

- 

- 

- 

N 37" E 

N 38" E 

- 

N 37" E, 

Washington.. ......... Greene ............... Wetzel and Monongalia 

Marion and Mononnalia 

N 5" E 

N 4" E 

N 57" w 

N 58" W 

- 

- 

N 61" W 

N 49" w 

- 

N 51" W 

N 51" W 

N 51" W 

N 7" E 

N 2" E 

N 5" E 

N 2" E 

1, 2, 3 

4, 5 

G 

7 

N 73" W 

N 75" w 

N 67" W 

N 68" W 

- 

- 

N 40" W - 

- 

- 

- 

N 14" E 

N 13" E 

N 15" E 

N 14" E 

N 14" E 

N51°WN59"W N40°W 

N 33" W 

N 28" W - 

- 

N 35" W 

N71°WN32"W 

N 21" W 

N 19" W - 

N 20" W 

- 

Washington ........... Greene.. ............. We tze 1 and Monongalia 

Marion and Monongalia 

Marion and Harrison.. 

- 

N 21" E 

N20°W Directional mean.. 

1, 2, 3 

4, 5 

6 

7 

8 

N 27" E 

N 27" E 

N 6" W - 

- 

N 5" W 

N 7" W 

- N6"W 

N 39" E 

N 38" E 

- 

N 49" E 

N 59"E 

N 61" 
TABLE A-2. - Average photolineament trends, by county 

County 

WEST 

1 I 2 1 3 I 4 I 5 I 6 I 7 

Tier 

Washington ............ Greene ................ Wetzel and Monongalia. 

Mar ion and Mononga 1 ia . - 

Marion and Harrison... 

Directional mean.. . 

divergence from north and not by their order of dominance. Trends in the same vert

of a group are assumed correlative through the counties. 

Groups 

EAST 

1, 2, 3 

4, 5 

6 

7 

8 

- 

Washington ............ Greene ................ Wetzel and Monongalia. 

Marion and Monongalia . Marion and Harrison... 

Directional mean.. . 

N 3" W 

N 3" W 

N 4" W 

N 4" W 

N 3" W 

N 3" W 

NOTE.--Numbered trends are arranged within the 2 directional groups (west and east) by inc

1, 2, 3 

4, 5 

6 

7 

8 

- 

N 13O W 

N 13" W 

N4"E 

N 5" E 

N 2" E 

N 3" E 

- 

N 4" E 

N 12" W 

N 14" W 

- 

N 11" W 

N 21" W 

N 24" W 

N 18" W 

- 

N 30" W 

- 

N 29" W 

N30°W 

N 23" W 

N 22" W 

N13"E 

- 

N 15" E 

N 15" E 

N 16" E 

N 15O E 

N 39" W 

N 41" W 

N 44" W 

N43"W 

N 35" W 

N 31" W 

N 19"E 

N 20" E 

N 24" E 

N 25" E 

N 24" E 

N 22" E 

N 52" W 

N 54" W 

N 51" W 

- 

N 43" W 

N 42" W 

N37"E 

N 31" E 

N 32" E 

N 37" E 

N 38" E 

N 35" E 

N 66

N 65

N 65

N61

N 52" W 

N 52" W 

N51°E 

N 44" E 

N 54" E 

- 

N 50" E 

N 50" E 

N 69

N 65

N63"E 

N 62" E 

- 

- 

N 63" E 

N 63" E 

N78

N 75

N72

N 69

- 

N 74
TABLE A-3. - Average Ronchi photoindex sheet lineament trends, by county 

County 

Monongalia ............................. I N 8O E ( N 23" E I N 58" E I N 80" E 

EAST 

- 

Marion.. ............................... N 6" E N 20" E N 58O E N 78" E 

Directionalmean ..................... N llOE N25"E N56"E N 78"E 

NOTE.--Numbered trends are arranged within the 2 directional groups (west and 

Groups 

east) by increasing divergence from north and not by order of dominance. 

WE ST 

N 73" E 

N79"E 

Trends in the same vertical column of a group are assumed to be cor1 1 2 4 

N 51' E 

N56"E 

Washington.. ........................... Greene ................................. 

relative through the counties. 

3 

N 70°W 

N 69" W 

N70°W 

N 73O W 

N71°W 

74 U.S. GOVERNMENT PRINTING OFFICE: 1977-703-001 152 

Washington ............................. Greene.. ............................... Monongalia ............................. Marion.. ............................... Directionalmean .................... 

N lgO E 

N1lOE 

N 24" W 

N 23" W 

N22"W 

N 24" W 

N23"W 

N lo0 W 

N 8" W 

N 8"W 

N 8" W 

N 9"W 

N 30" E 

N25"E 

N 45" W 

N 42" W 

N43"W 

N 43" W 

N43"W