Bureau of Mines Report of Investigations/l976 

Determining Cleat Orientation 

of Deeper Coalbeds 

From Overlying Coals 

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

Thomas S. Kleppe, Secretary 

BUREAU OF MINES 

Thomas V. Falkie, Director 
This publication has been cataloged as follows : 

I 

McCulloch, Charles M 

Determining cleat orientation of deeper coalbeds from 

overlying coals, by C. M. McCulloch, S. W. Larnbert, and 

J. R. White. [Washington] U.S. Bureau of Mines 119761 

19 p. illus., tables. (U.S, Bureau of Mines. Report of investigations 8116) 

Includes bibliography. 

1. Coal mines and mining. 2. Degassing of coal. I. Lambert, 

S- W., jt. auth. 11. White, James R., jt. auth, 111. U.S. Bureau 

of Mines. IV, Title. V. Title: Cleat orientation of deeper 

coalbeds. ' (Series) 

TN23.U7 no. 8116 622.06173 

U.S, Dept. of the Int. Library 

J 
CONTENTS 

bstract ................................................................. 1 Introduction ............................................................. Acknowledgments .......................................................... \Historical background .................................................... current studies .......................................................... Studies of adjacent coalbeds mined underground ........................... Sewickley and Pittsburgh coalbeds ................................... Upper and Lmer Kittanning coalbeds ................................. American and Mary Lee coalbeds ...................................... Studies of adjacent strip-mined coalbeds ................................. Southwestern Pennsylvania ........................................... Southern West Virginia ............................................ *. 

Conclusions .............................................................. 

ILLUSTRATIONS 

Location of Warwick No . 3 mine (Sewickley coalbed) in relation to 

the Shannopin mine (Pittsburgh coalbed) . Greene County. Pa ........ 4 

Stratigraphic column showing Sewickley and Pittsburgh coalbeds 

and adjacent strata ............................................... 4 

Rose diagrams of coal cleat orientations of the Beckley and 

Pittsburgh coalbeds ............................................... 5 

Location of Cambria No . 33 C' mine (Upper Kittanning coalbed) in 

relation to the Cambria No . 33 B mine (Lower Kittanning 

coalbed). Cambria County. Pa ...................................... 6 

Stratigraphic column showing the Upper and Lower Kittanning 

coalbeds and adjacent strata ...................................... 6 

Rose diagrams of coal cleat orientations of the Upper and Lower 

Kittanning coalbeds ............................................... 7 

Location of Gorgas No . 7 mine (American coalbed) in relation to 

the Mary Lee No . 1 mine (Mary Lee coalbed). Walker County. Ala .... 8 

Stratigraphic column showing the American and Mary Lee coalbeds 

and adjacent strata ............................................... 9 

Rose diagrams of coal cleat orientations of the American and Mary 

Lee coalbeds and coal cleat measured from the outcrop ............. 9 

Location map showing three strip mine locations. Fayette County. Pa . 10 

Generalized stratigraphic column of coalbeds. Fayette County. Pa .... 11 

Rose diagrams of coal cleat orientations of Clarion and Brookville 

coalbeds. Fort Necessity quadrangle. Fayette County. Pa ........... 12 

Rose diagrams of coal cleat orientations of Bakerstown and Brush 

Creek coalbeds . Connellsville quadrangle. Fayette County. Pa ...... 12 

Rose diagrams of coal cleat orientations of Washington and 

Waynesburg coalbeds. Camichaels quadrangle. Fayette County. Pa . . 13 

Stratigraphic position and cleat orientations of six coalbeds in 

Raleigh and Wyoming Counties. W . Va .................... ..... ...... 14 
ILLUSTRATIONS--Cont inued 

Page 

16. Location of strip mines and deep mines in the Raleigh and Wyoming 

Counties, W. Va., study areas. .................................... 15 

17. Stratigraphic sections of interval from the No. 2 Gas coalbed to 

the Beckley coalbed ............................................... 16 

18. Con~posite rose diagram of cleat orientation for three underground 

mines in Raleigh and Wyoming Counties, W. Va.. .................... 16 

TABLES 

1. Face and butt cleat orientations in the Warwick No. 3 and Shannopin 

mines ............................................................. 4 

2. Face and buttecleat orientations in the Cambria No. 33 C' and 

B mines. .......................................................... 7 

3. Face and butt cleat orientations in the outcrop and in the No. 7 

and Mary Lee No. 1 mines. .................................. 10 

4. Face and butt cleat orientations in strip mines studied in Fayette 

County, Pa. ....................................................... 13 

5. Face and butt cleat orientations in six overlying coalbeds and in 

three deep mines, Raleigh and Wyoming Counties, W. Va.. .......... a 17 
DETERMINING CLEAT ORIENTATION OF DEEPER COALBEDS 

FROM OVERLYING COALS 

by 

Co Mo McCul loch, 1 So W. Lambert, 1 and Jo Ro White 1 

ABSTRACT 

Examination of several coalbeds in Walker County , Ala . , Cambria , Greene , and Fayette Counties, Pa., and Raleigh and Wyoming Counties, W. Va., indicates 

that cleat orientations are similar throughout a vertical sequence of strata. 

Studies of cleat orientation were carried out in underground mines that 

are operating in separate coalbeds vertically above one another. The data 

show that over a vertical separation of 100 to 400 feet, the average difference in coal cleat orientation between mines is 04" for the face and 08" for 

the butt cleat. Variations of coal cleat direction between coalbeds examined 

in strip-mined areas show similar values. Cleat orientations measured at 

outcrops agree well with the directions measured underground, suggesting that 

the amount of vertical separation between coalbeds has little effect on the 

resulting differences in cleat directions. The largest variation of cleat 

directions between adjacent coalbeds occurs where a large horizontal distance 

separates two sample locations. Cleat orientations for deeper coalbeds are 

most reliable where the data are taken from directly above. 

INTRODUCTION 

The Bureau of Mines has demonstrated that the amount of gas flowing 

through a coalbed is controlled by the orientation of natural fractures 

present within the coal (6-1, 2) ." Such fractures appear to occur universally 

in all ranks of coal (5, -- 9-13) and impart important directional permeability 

properties to coalbed gas reservoirs. Production of fracture orientations in 

advance of mining is becoming increasingly important as new mines open and 

operate under greater overburden pressures where gas content is expected to be 

high. The ability to predict cleat orientation in advance of mining by studying overlying coals is essential to developing a rational degasification 

program for reducing explosion hazards, for increasing mine productivity, and 

for conserving natural gas contained in the coalbeds. 

l~eologist . "underlined numbers in parentheses refer to items in the list of references 

at the end of this report. 
Coal may contain several sets of fractures. Those normal to bedding in 

coal are called "cleat" and are analogous to joints in other rock types. Cleat 

in coal occurs as two fracture sets oriented at approximately 90" to each 

other. One cleat is usually much better developed than the other, exhibiting 

larger and more continuous fracture surfaces. This fracture is commonly known 

as the face cleat. The other set, called the butt cleat, is less continuous, 

is often curved, and frequently terminates against the face cleat. 

Cleat orientations were measured in Pennsylvania and Alabama where coal 

is mined from coalbeds one above the other and in Pennsylvania and West Virginia where a number of coalbeds are being stripped in a vertical sequence. 

The purpose of this study was to determine the relationship between cleat 

directions for coalbeds located at different stratigraphic levels at a given 

location. 

The authors thank the staffs of all the mines and companies from which 

data were collected. Cleat surveys were made underground and in the strip 

pits with the cooperation of the individual company officials. Without the 

assistance of the individual companies a report of this type would not be 

possible. 

HISTORICAL BACKGROUND 

As early at 1915, Hofer (4) recognized that the orientation of coal 

cleats and rock joints was essentially the same throughout a vertical sequence. 

Ver Steeg (15) in eastern Ohio, Hodgson (3) in Arizona and Utah, Parker (ll) 

in New York, and Stutzer and Nbe (2) and Kendall and Briggs (2) in Great 

Britain have all noted similar findings, but have different explanations as 

to how rock joints and coal cleats were formed. 

There have been reports that coal cleats do not always show the same 

directions through a vertical sequence. In 1925, Dron (2) studied coalbeds 

in Scotland and found that the cleat directions varied between upper and lower 

seams in the same coalfield. 

In 1967, Nickelsen and Hough (lo), working in the Appalachian Plateau, 

demonstrated that for similar rock types throughout the stratigraphic section, 

joints (including cleats) shawed similar strike and spacing. 

CURRENT STUDIES 

In 1974, McCU~~OC~, Deul, and Jeran (2) reported that cleat orientations 

varied only slightly within individual mines;where the variation was large 

or differed greatly, the area was closely examined and often structural faults 

were located. 

Diamond, McCulloch , and Bench (L) found that underground cleat orientations over a large area could be successfully predicted from surface joint 
measurements and photolinears obtained from infrared photographs. Cleat 

orientations of individual mines were predicted approximately 80 pct of the 

time using surface data gathered directly above and adjacent to the mine. 

The ability to predict fracture orientations in advance of mining is 

becoming increasingly important as new mines open in deep coalbeds where the 

gas content is expected to be high. Such fractures in coal are natural 

avenues through which fluids flow most easily and provide directional permeability characteristics to the coalbed (5-1). In one study, coal gas flow 

parallel to the more continuous face cleat was found to be 2.5 to 10 times 

greater than flow parallel to the butt cleat (2). Advance knowledge of the 

cleat orientation will assist in the planning of degasification programs as 

to the most efficient placement of vertical, horizontal, or directional slant 

boreholes . STUDIES OF ADJACENT COALBEDS MINED UNDERGROWID 

Little multiple-coalbed mining has taken place in this country since in 

the past the low price of coal and the readily available supply of petroleum 

has discouraged such mining practices. However, increasing demand for fuel, 

the increasing depths necessary to acquire high-quality coal, and the unresolved disputes about surface mining will probably make multiple-coalbed 

mining more necessary . 

Three areas were found where two coalbeds are being actively mined, one 

over the other : In Greene County, Pa. , the Sewickley and Pittsburgh coalbeds ; 

in Cambria County, Pa., the Upper and Lower Kittanning coalbeds; and in Walker 

County, Ala., the American and Mary Lee coalbeds. It should be pointed out 

that mines in these areas do not necessarily have active workings directly 

over each other. Normally the lower coalbed advances first and the upper coalbed is mined in the same area later; eventually both coalbeds are accessible 

in the same area. 

Sewickley and Pittsburgh Coalbeds 

In southeas tern Greene County, Pa. , where the Sewickley and Pittsburgh 

coals are mined, the vertical separation is approximately 100 feet. The 

Sewickley, the upper coalbed, is mined from the Warwick No. 3 mine operated 

by Duquesne Light Co., whereas the deeper Pittsburgh coalbed is mined from the 

Shannopin mine, operated by Jones and Laughlin Steel Corp. 

Figure 1 shows the location and the relation of the mines to each other. 

Figure 2 is a stratigraphic column of the area showing both coalbeds and adjacent strata. 

Face cleat orientations measured in the Warwick No. 3 mine indicate an 

average face cleat direction of N 77" W for the Sewickley coalbed. The butt 

cleat has an average orientation of N 18" E. 

Measurements taken of the Pittsburgh coal cleat in the Shannopin mine 

indicate the face and butt cleats to be oriented at approximately N 73" W and 
Greene County, Pa. 

N 18" E, respectively. The distributions of face and butt cleat directions 

for both the upper and lower coals are shown on figure 3. 

Comparison of cleat orientations in both mines indicates that cleat 

directions are similar even though the two coalbeds are vertically separated 

by 100 feet. The N 77" W face cleat direction for the Sewickley coalbed 

compares favorably with the N 73" W face cleat measured in the Pittsburgh 

coalbed. The average butt cleat directions are identical. Table 1 sumanarizes 

the information obtained from cleat readings taken in both mines. 

TABLE 1. - Face and butt cleat orientations in the 

Warwick No. 3 and Shannopin mines 

'separation is defined as the angular difference between the average face 

and butt cleat directions. Ideal separation is 90". 

2~ifference in cleat direction. 

Mine 

Warwick No. 3. 

Shannopin. .... 

Coalbed 

Sewiskley. 

Pittsburgh 

A 

Approximate 

vertical 

separation, ft 

100 

Degrees of 

separation1 

9 5 

9 1 

- 

Average orientation 

Face cleat 

N 77O W 

N 73" W 

a 04" 

Butt cleatN 18" E 

N 18" E 

2 00" 
Average 1 butt cleat 

Lrl 

299 readings 16 measurements 

Shannopin mine 

Pittsburgh coalbed 

Average 

Iz0 butt cleat 

N 18OE 

W E 

LrJ, 140 readings 16 measurements 

Warwick No. 3 mine 

Sewickley coalbed 

Key Map 

FIGURE 3. - Rose diagrams of coal cleat orientations of the Beckley and Pittsburgh coolbeds. 

Upper and Lower Kittanning Coalbeds 

In Cambria County, Pa. , the Upper and Lower Kittanning coalbeds are mined 

at the Cambria No. 33 B and C' mines. The vertical separation is 100 feet. 

Both mines are operated by Bethlehem Mines Corp. The Lower Kittanning 

(B coalbed) has been mined for 11 years, whereas the Upper Kittanning (C ' 

coalbed) has only been worked for 5 years. Figure 4 shows the spatial relation of the coalbed workings to each other. Figure 5 is a stratigraphic 

column taken from company core logs showing the position of both coalbeds and 

adjacent strata. 

Cleat orientations for the Lower Kittanning coalbed are shown in 

figure 6. The face cleat trends approximately N 69" W. The butt cleat direction averages N 19" E. 

The Upper Kittanning coal cleat directions also are shown in figure 6. 

The average face cleat direction is N 67" W. The butt cleat shows variation 

in trend with at least three peaks shown on the rose diagram, but the average 

butt cleat direction is N 22" E. 
Cambrio No. 3#=, 

I 

1 Pennsylvani

B mine ; tF> I i ' I 

/I/ // 

// / 

1. 0 4,00

-

Scale, ft 

FIGURE 4. - Location of Cambria No. 33 C' mine (U

Kittanning coalbed) in relation to the 

bria No. 33 B mine (Lower Kittanning c

bed), Cambria County, Pa. 
Averoge N butt cleat 

1,725 reodings 40 meosurements 

Cornbrio No. 33 mine (8 seam) 

Lower Kittonning cool bed 

Averoge 

foce cleot 

N 67OW 

Averoge 

butt cleat 

N 2z0 E 

L,rJ 

200 reodings 8 meosurernents 

Combrio No.33 mine (C prime) 

Upper Ki ttonning coal bed 

Pennsylvania 

FIGURE 6. - Rose diagrams of coal cleat orientations of the Upper and Lower Kittanning 

coa lbeds, 

There is a very close correlation between the average coal cleat directions in the upper and lower coalbeds. The difference in face cleat directions is only 02", and the difference in butt cleat directions is only 03". 

The information is summarized in table 2. 

TABLE 2. - Face and butt cleat orientation in the 

Cambria No. 33 C' and B mines 

Mine 

Cambria No. 33 

C. 

Cambria No. 33 

B. 

lseparation is defined as the angular difference between the average face 

and butt cleat directions. Ideal separation is 90". 

2Difference in cleat direction. 

Degrees of 

separation1 

89" 

88" 

I 

Coalbed 

Upper 

Kit tanning. 

Lower 

Kittanning. 

Approximate 

vertical 

separation, ft 

100 

Average orientation 

'E'ace cleat 

N 67" W 

N 69" W 

2 02" 

Butt cleat' 

N 22" W 

N 19" E 

203" 
American and Mary Lee Coalbeds 

The American and Mary Lee coalbeds are mined in Walker County, Ala. , in 

what is physiographically known as the Warrior basin. The vertical separation 

here is approximately 400 feet, with the American being the upper coalbed. 

The coalbeds are mined by the Alabama By-Products Corp. from the Gorgas No. 7 

and Mary Lee No. 1 mines. Figure 7 shows the location and relation of the 

mines to each other. Figure 8 is a stratigraphic column of the area showing 

the position of the two coalbeds and adjacent strata. Cleat orientations for 

both mines and coal outcrop are represented by rose diagrams shown on figure 9. 

The American coalbed is mined from the Gorgas No. 7 mine. Cleat orientations for the American coalbed are face cleat N 58" E and butt cleat N 37" W, 

a separation of 95". The Mary Lee coalbed is mined below from the Mary Lee 

No. 1 mine (fig. 7). Here the face cleat orientation is N 63" E , while the 

butt cleat averages N 33" W. 

Again the face cleat directions of both coalbeds are similar. In this 

example, the face cleat varies only 05" , and the butt cleat by 04". 

Key Mop 

Alabamo 

FIGURE 7. - Location of Gorgas No. 7 mine (American coalbed) in relation to the Mary Lee 

No. 1 mine (Mary Lee coalbed), Walker County, Ala. 
Average 

face cleat 

Average N 58"E 

butt cleat 

N 37"W 

EW E 

'-,-I k-' 

30 readings 4 measurements 92 readings 8 measurements 193 readings 4 measurements 

Unnamed coal from outcrop Gorgas No. 7 mine 

American coalbed 

Mary Lee No. l mine 

Mary Lee coolbed 

FIGURE 9, - Rose diagrams of coal cleat orientations of the American and Mary Lee coalbeds 

and coal cleat measured from the outcrop. 

In this area there are a number of outcrops of coal. Cleat measurements 

were taken; the face cleat was found to be N 58" E (fig. 9), and the butt 

cleat was N 35" W. Again, from table 3, it is evident that the cleat directions from all three coalbeds are similar, despite a total vertical separation 

of 600 feet. 
TABLE 3. - Face and butt cleat orientations in the outcrop and 

in the GO~R~S No. 7 and Mary Lee No. 1 mines 

Mine 

'separation is defined as the angular difference between the average 

Outcrop ....... Gorgas No. 7. . Mary Lee No. 1 

face and butt cleat directions. Ideal separation is 90". 

2Maximum difference in cleat direction. 

Coalbed 

STUDIES OF ADJACENT STRIP-MINED CQALBEDS 

Unnamed. 

American 

Mary Lee 

Several strip-mined locations where two or more coalbeds have been 

exposed were examined. Measurements were taken from at least two coalbeds 

within a single stripped area and compared to determine cleat orientation 

relationships. Two areas were examined. The first was in southwest Pennsylvania, where two adjacent coals are strip-mined, and the second was in southern West Virginia, where several coalbeds are being stripped in the same 

vicinity. This area also has several underground coal mining operations where 

cleat orientations were measured and compared with surface cleat directions. 

Approximate 

vertical 

LEGEND 

A Strip mine location 

separation, ft 

200 

400 

Pennsylvania 

0 10 

Average orientation 

Face cleatl~utt cleat 

Scale, miles 

Degrees of 

separation1 

N58"E 

N 58' E 

, N 63" E 

2050 

Connellsville 

quodrangle I 

Cormichaels 

Y 

quadrangle 

N35"W 

N 37" W 

N 33" W 

04" 

FIGURE 10. - Location map showing three 

strip mine locations, Fayette County, Pa. 

93 

95 

96 

- 

FAYETTE COUNTY /- 

40rt Necessity 

quodrongle 
Pennsylvania 

Beol~n coal County, Pa. 

Horlem cool 

Bokerstown cool 

Brush Creek cool 

Upper Freeport cool 

Lower Freeport coal 

Upper Kittonning cool 

Middle Kittonning cool 

Lower Ki ttonn~ng cool 

Clorion cools 

Brookville coal 
The second area examAverwJ2b~ iFt 

ined is in the Connellsville 

7 -112 -minute quadrangle. 

face ckat face cleat Here the upper coalbed, the 

N 68O W N 64OW Bakerstm coal, has an 

average face cleat direction 

+' w 27 readings 2 measurements 13 readings l measurement 

of N 66" W and an average 

butt cleat of N 22" E 

Brookville coal Clarion coal (fig. 13) . The lower coal - 

bed, the Brush Creek, has a 

face cleat striking N 67" W 

and a butt cleat striking 

Key Map N 26" E. The two coalbeds 

are separated by about 

FIGURE 12. - Rose diagrams of coal cleat orientations of 60 feet of sandstone and 

Clarion and Brookvi l le coalbeds, Fort shale. 

Necessity quadrang le, Fayette County, Pa. 

'4 

33 reodings 2 measurements 

Average 

foce cleat 

N 67O W 

Brush Creek cool 

Average 

butt cleot 

N 26O E 

Key MOP 

Average 

foce cleat 

N 66O W 

Average 

butt cleot 

N 22O E 

Y 

20 readings 2 measurements 

Pennsylvonio 

Bokerstown coal 

The third strip-mined 

area studied is in the 

Carmichaels quadrangle. The 

Washington coalbed, the 

upper coalbed, has a face 

cleat striking N 71" W; the 

butt cleat strikes N 19" E. 

Fifty feet below, the 

Waynesburg coalbed has a 

face cleat striking N 65" W 

with the butt cleat striking 

N 29" E. Figure 14 shows 

rose diagrams of the cleat 

orientations for both these 

coals. 

FIGURE 13. - Rose diagrams of coal cleat orientations of Face and butt cleat 

Bakerstown and Brush Creek coalbeds, orientations for all three 

Connellsville quadrangle, Fayette County, strip mines are shown on 

Pa. table 4. 

In the three stripmined areas of southwestern Pennsylvania studied, there appears to be an 

excellent correlation of cleat orientation through vertical sequences of coalbeds. The largest angular difference between cleat orientation of upper and 

lower coalbeds observed was 06" for the face cleat in the Carmichaels quadrangle and 10" for the butt cleat in the Connellsville quadrangle. The 

average deviation of face and butt cleats between vertically separated coalbeds is 04" and 07", respectively. Similar deviations in cleat directions 

have been noted in individual coalbeds at a single location. 
t Average 

N 

t Average 

Averoge butt cleat 

face cleat I N 29"E 

Li 

27 readings 2 measurements 

Waynesburg 

coo D 

Average butt cleot 

face cleat I N1gOE 

i 

13 readings I measurement 

Washington 

coa l 

Pennsylvania 

FIGURE 14. - Rose diagrams of coal cleat orientations of Washington cmd Waynesburg coalbeds, Carrnic haels quadrangle, Foyette County, Pa. 

TABLE 4. - Face and butt cleat orientations in strip mines 

studied in Fayette County, Pa. 

Coalbed 

Fort Necessity quadrangle: 

Clarion .................... Br ookvi 1 le ................. Conne llsville quadrangle : 

Bakerstown ................. Brush Creek ................ Cannichaels quadrangle: 

Washington ................. Waynesburg ................. 

Approximate 

vertical 

separation, ft 

lseparation is defined as the angular differ !rice between the average face 

Avzrage orientation 

Face cleat 1 Butt cleat 

and butt cleat directions. Ideal separation is 90". 

2~aximum difference in cleat direction. 

Degrees of 

separation1 

Southern West Virginia 

Surface and subsurface information gathered in Raleigh and Wyoming 

Counties, W. Va. , indicates cleat orientations to be similar throughout the 

sequences of strata examined. 
No. 2 gas cool 

20 readings 

Eagle cool 

22 readings 

Little Eogle coal 

26 reodings 

Lower War Eagle coal 

15 readings 

Gilbert cool 

18 reodings 

Douglos cool 

22 readings 

Key Mop 

FIGURE 15. - Stratigraphic position and cleat orientations of six coalbeds in Raleigh and 

Wyoming Counties, W. Va. 
A particularly good example of the persistence of cleat direction through 

a vertical sequence is shown on figure 15. This shows the stratigraphic 

position and cleat orientation of six different coalbeds which were examined 

in an area of active strip-mining operations in Raleigh County. The Douglas 

coal, which is stratigraphically the lowest coal examined, is separated £ram 

the uppermost No. 2 Gas coalbed by some 300 feet of sandstone and shale. The 

six coalbeds were studied within an area of approximately 2 square miles. 

The face cleat directions of all six coals are within 06" of each other, 

the average direction being N 46" W. The average butt cleat direction is 

N 46" E, with a separation of 92". Variation in butt cleat direction is 12". 

Surveys of cleat directions were conducted at three nearby underground 

coal mines south and east of the strip-mined area by Popp (l2) in 1974. 

Figure 16 shows the locations of these mines. The deep mines are presently 

working in the Beckley coalbed which is stratigraphically approximately 750 

feet below the No. 2 Gas coalbed (fig. 17). 

Distributions of cleat directions for all three deep mines have been 

graphically displayed in figure 18. The average face cleat direction is 

N 36" W. This is 10" from the N 46" W face cleat direction of the six coals 

examined on the surface. Distributions of butt cleat directions for the three 

deep mines in the Beckley show greater variation than for the six different 

surface coalbeds. The average butt cleat direction of N 60" E is 14" to the 

east of the average butt cleat direction measured on the surface. 

i 

LEGEND 

Surface coal cleat measurement 

B 

loco t ion 

Underground mine location - e 4-A 

t 0 

WYOMING 

COUNTY \ RALEIGH 

@ \ COUNTY 

FIGURE 16. - Location of strip mines and deep 

mines in the Raleigh and Wyoming Counties, W. Va., study 

areas. 

0 - I6,OOO 

Scale, ft 
No. 2 gas coal 

Douglas coal 

Sewell coals 

Beckley coal 

Fire Creek coal 

Key 

FIGURE 17, - Stratigraphic sections of interval from 

No. 2 Gas coalbed to the Beckley coalb
Face and butt cleat information measured in the six successive coalbeds 

and in the three deep mines is summarized on table 5. 

TABLE 5. - Face and butt cleat orientations in six overlying coalbeds and 

in three deep mines, Raleigh and Wyoming Counties, W. Va. 

CONCLUSIONS 

Bureau research in the Appalachian coalfields shows that the directions 

of cleat orientations are similar throughout vertical sequences of coal-bearing 

Degrees of 

separation1 

92 

92 

96 

90 

88 

94 

95 

85 

109 

strata. In areas examined, coals that are separated vertically by as much as 

400 to 700 feet show similar directions of cleat orientations. 

lseparation is defined as the angular difference between the average face and 

butt cleat directions. Ideal separation is 90". 

"~a~le Meadow. 

~eckle~. 

4Beckley No. 1. 

The vertical distance which separates two coalbeds apparently has very 

little effect on differences in cleat orientations in the areas examined. 

Coalbeds studied in some strip-mined areas separated by 50 feet or less show 

face cleat variations between coalbeds from 05" to 06" similar to coalbeds separated by up to 400 feet of such strata. A corresponding relationship 

of butt cleat variation with vertical separation also is observed, although 

butt cleat orientations tend to be irregular and the variations in measureApproximate 

stratigraphic 

separation 

between 

coalbeds, ft 

35 

45 

70 

65 

85 

250 

(2 1 

(3 1 

(4 ) 

County 

Wyoming.. 

DO.. ... Raleigh.. 

Do.. ... Do ..... Do.. ... 

Do..... 

DO .......... Wvominp.. 

Direction 

ments between coalbeds are somewhat higher. 

Coalbed 

No. 2 Gas.. .... Eagle.. ........ Little Eagle.. . War Eagle.. .... Gilbert ........ Douglas ........ 

Beckley ........ do. ....... ..... do.. ...... 

' Face cleat 

N 48" W 

N 43" W 

N46"W 

N 46" W 

N 49" W 

N43"W 

N 35" W 

N 36" W 

N37"W 

'The largest variations of cleat direct ions between over lying coalbeds are 

shown to occur where a large horizontal distance separates two locations where 

coalbeds were examined. In south-central West Virginia, the strip-mined area 

examined is over 3 miles from the nearest deep coal mine in which cleat readings were taken. The difference in face cleat directions between the two 

locations is lo0, while the butt cleat orientations differed by 14". 

Butt cleat 

' N 44" E 

N 49" E 

N50°E 

N 44" E 

N 39" E 

N51°E 

N 60" E 

N 49" E 

N72"E 
The results of this study show that suitable cleat measurements can be 

taken from coalbeds in a deep mine, strip mine, or outcrop, so long as a 

representative sample of the cleat orientation is taken. No significant deviations were found in any of the studies to suggest a preferential method to be 

used, although outcrop readings of sufficient number over a small area are 

difficult to obtain. 

Best results are noted where two coalbeds were measured directly or 

nearly directly over each other without regard to amount of vertical separat ion. Differences in cleat orientations between upper and lower coalbeds 

became significant when the horizontal distance between measuring points 

increased. 

Knowing that coalbeds have the same major cleat orientations throughout 

a vertical sequence will become more important as mining progresses under deep 

overburden. Because gas content of coalbeds generally increases with depth, 

some form of degasification will be necessary if very deep coalbeds are to be 

mined productively. The ability to predict cleat orientations before degasificationwil assist in the planning of degasification programs and greatly add 

to our knowledge of the behavior of coalbed gas reservoirs. 
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. Dron, R. W. Notes on Cleat in the Scottish Coalfield. Trans. Inst. Min. 

Eng., v. 70, 1925, pp. 115-117. 

3. Hodgson, R. A. Regional Study of Jointing in Comb Ridge-Nawaho Mt. Area, 

Arizona and Utah. AAPB Bull., v. 45, 1961a, pp. 1-38. 

4. Hofer , H. Schwandspalten (Schlechten, Lassen) [shrinkage Cracks (Cleats, 

Separations)]. Mitt. Geol. Ges. Wien, v. 7, Nos. 1 and 2, 1915. 

5. Kendall, P. F., and H. Briggs. The Formation of Rock Joints and the 

Cleat of Coal. Proc. Royal Soc., Edinburgh, v. 53, 1933, pp. 164-187. 

6. Kissell, F. N. Methane Migration Characteristics of the Pocahontas No. 3 

Coalbed. BuMines RI 7649, 1972, 19 pp. 

7. . The Methane Migration and Storage Characteristics of the Pittsburgh, Pocahontas No. 3, and Oklahoma Hartshorne Coalbeds. BuMines 

RI 7667, 1972, 22 pp. 

8. Macrae, J. C., and W. Lawson. The Incidence and Cleat Fracture in Some 

Yorkshire Coal Seams. Trans. Leeds Geol. Assoc., v. 6, 1954, 

pp. 224-227. 

9. McCulloch , C. M. , M. Deul , and P. W. Jeran. Cleat in Bituminous Coalbeds. BuMines RI 7910, 1974, 25 pp. 

10. Nickelsen, R. 0. , and V. D. Hough. Regional Orientation of Joints in the 

Appalachian Plateau. Abs., Geol. Soc. Am. Bull., v. 69, 1967, p. 1624. 

11. Parker, J. M., 111. Regional Systematic Jointing in Slightly Deformed 

Sedimentary Rocks. Geol. Soc. Am. Bull. , v. 53, 1942, pp. 381-408. 

12. Popp, J. T. The Geological Factors Controlling the Migration, Retention, 

and Emission of Methane in the Beckley Coalbed. M.S. Thesis, Southern 

Ill. Univ., 1974, pp. 39-43. 

13. Raistrick, A., and C. E. Marshall. Nature and Origin of Coal and Coal 

Seams. The English University Press Ltd. , London, 1939, 262 pp. 

14. Stutzer , 0. , and A. C. Noe. Geology of Coal. University of Chicago 

Press, Chicago, Ill., 1940, 461 pp. 

15. Ver Steeg , K. Jointing in the Coalbeds of Ohio. Econ. Geol. , v. 37, 

1942, pp. 503-509. 

=Title enclosed in brackets is a translation from the language in which 

the item was published. INT.-BU.OF MINES,PGH.,PA. 2090 1