Lithologic and geochemical investigations of the Fire Clay coal bed, southeastern Kentucky, in the vicinity of sandstone washouts

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International

E LS EV | E R

Journal

of

International Journal of Coal Geology 26 ( 1994) 95-115

Lithologic and geochemical investigations of the Fire Clay coal bed, southeastern Kentucky, in the vicinity of sandstone washouts W i l l i a m M. A n d r e w s , Jr. a'bA, J a m e s C. H o w e r b, J o h n K. H i e t t b aDepartment of Geological Sciences, 101 Slone Building, Universityof Kentucky, Lexington, KY40506-0053, USA bUniversity of Kentucky Centerfor Applied Energy Research, 3572 Iron Works Pike, Lexington, KY40511-8433, USA (Received June 28, 1993; revised version accepted March 15, 1994)

Abstract The Fire Clay (Hazard No. 4) coal bed of the Middle Pennsylvanian Breathitt Formation in eastern Kentucky is interrupted by a series of discontinuous sandstone bodies. This sand belt, which includes two washouts, was studied in Perry County. The coal thickens toward the interruptions and the coal between the sand bodies is highly disturbed. Several prominent durains in the upper bench of the coal bed are laterally continuous within the study area. Statistical analysis indicates that the durain layers contribute much of the vertical coal quality variation. The sandstone bodies are inferred to be a result of post-depositional fluvial activity and the disturbance of the coal between washouts is due to compaction-related slumping. A thin kaolinite-rich lens similar to the flint clay parting was found below the main parting.

1. Introduction The Fire Clay ( H a z a r d No. 4) coal bed is an extensive coal bed in the central Appalachian basin and correlatives o f this coal can be found in eastern Kentucky, West Virginia, western Virginia and eastern Tennessee. In the eastern Kentucky coal field, the Fire Clay is assigned to the Breathitt F o r m a t i o n o f Middle Pennsylvanian age (late Westphalian B in Europe, U p p e r M o r r o w a n in the Illinois Basin). tPresent address: Department of Geology, Duke University, Durham, NC 27708-0229, USA. 0166-5162/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDI 0166-5162 (94)00004-J

96

~2M, ,Indrews, Jr. eta/. ' h~ternationad.lourna/ r!/('oal Geology 26 (1994) 95 ~I i5

The coal is low rank, high volatile A, bituminous and has moderate ash (mean ~ 10%) and low sulfur (mean ~ 1%), which makes it an important resource for the region. In 1991, 21.5 million short tons of this coal were mined in Kentucky, making it the second largest producing coal bed in the state, and the leader in the eastern Kentucky coal field. Metallurgical and utility markets are the primary customers of this coal. Hower et al. (1994) and Eble et al. (1994) discuss the Fire Clay coal bed in the region from the standpoint of regional coal quality, with respect to utilization and paleodepositional environments, respectively. The coal bed contains a distinctive flint clay parting (the Fire Clay tonstein), which aids in identification of the seam in mines and outcrops, and provides a time-correlative datum throughout the basin. This parting is inferred to have a volcanic ash fall origin (Chesnut, 1983; Lyons et al., 1992) and is dominated by kaolinite, with minor microphenocrysts of sanidine,//-quartz paramorphs, euhedral zircons and Fe-Ti minerals such as ilmenite and futile (Bohor and Triplehorn, 1981; Lyons et al., 1992; Hower et al., 1994). Sanidines from the flint clay have been dated using 4°Ar/39At, yielding an age of 312 Ma _+ 1 Ma (Lyons et al., 1992). An extensive system of sandstone interruptions of the Fire Clay coal bed exists in the area of the Hyden East and Hazard South 7.5 minute quadrangles in southeastern Kentucky (Fig. 1 ). In some places the interruptions appear to have completely isolated large blocks of coal. The interruptions are subparallel, trending roughly east-west to northwest-southeast. They range from tens to hundreds of meters in width, from 0.1 to tens of kilometers in length, and occur in areas overlain by a larger sandstone body. Interpretation of drillers' logs indicate that this overlying sandstone is from 10 to 40 m thick and 4-5 km wide in places. Other investigators have discussed similar sandstone bodies associated with coal beds and generally associate such bodies with ancient fuvial processes. Nelson ( 1983 ) discussed a variety of geologic interruptions of coal beds in the Illinois Basin, including both contemporaneous (e.g., the Galatia and Walshville channels) and postdepositional (e.g., the Anvil Rock Sandstone) channels. He noted the occurrence of an 'island' of isolated coal, inferring a change in course of the eroding channel. Kertis ( 1985 ) examined the effects of channels on coal beds, including anomalous thicknesses and reduced coal quality (including higher ash and sulfur contents), due to partings and inferred fluid flow within the coal bed. Potter and Simon ( 1961 ) used subsurface data to delineate the Anvil Rock sandstone and discovered numerous small sand bodies associated with areas of thin or no coal, which are similar in distribution to the washout pattern shown in Fig. 1. These cutouts are, in turn, overlain by a major channel system. Guion ( 1987 ) described a sandstone channel from Derbyshire, England, which cut out the underlying seam, producing tilted and disturbed blocks of coal due to channel bank collapse. Weisenfluh and Ferm ( 1991 ) investigated the Fire Clay coal bed south of the present study area. They described episodic clastic deposition contemporaneous with deposition of the precursor peat. In places, fluvial processes have eroded the

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kilometers

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f

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4

I

Hazard South

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--'~cation

Cross Section Location

f

~Hazard f

of

f

/

f

37 ° 7' 30" N

83 ° 7' 30" W

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v-/

j

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37 ~ 15' N

Fig. 1. Map showing distribution of washouts in the Fire Clay coal bed. Hatch marks toward sandstone, dashed line indicates approximate extent of channel system overlying Fire Clay coal bed. Inset: location of quadrangles.

83 ° 22' 30" W

Hyden East

Hyden

D

x..

2

i

a

o

Study Area

I

¢3

•"~.

"-

J

T

meters

20

10

30 1

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0 leters

t

2

Site 5

11

-

~ Site 2

1 Site 3

1

1

C

Site 6

;ire 4

Zig. 2. Study area cross-section, showing exposure within mine, datum is mine floor, Note irregular profile o f mine roof. especialb within-sandst~,;>: podies. Location of tonstein not shown.

3

1

Site W S 1

1

;ite 1

3eneralized Cross Section

t,

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Site

41002

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South

ws1

II

tonstein

30 cm

2

4

4931

m

cannel

[]

4944

m

dull clarain / durain

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Fig. 3. Cross-section showing lithotype profile.

25 meters I i

[--"1 clarain / bright clarain

Petrographic Cross Section

4913 5

i'1~49~7

E

North

I

3

W.M. Andrews, Jr. et al. / International Journal ~[ Coal Geology 26 (l 994) 95-11,5

100

Table 1 Petrography, ash and sulfur data Site Interval K C E R #

Bench

5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 4 4 4 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 6 6 6

roof 1 69.6 parting 2 90.8 3 72.8 4 66.6 5 60.6 6 73.2 7 71.9 8 33.2 9 78.8 10 50.6 11 79.9 flint clay 12 76.6 13 69.9 14 43.7 floor roof 1 47.2 2 73.7 3 79.7 4 78.2 5 37.7 6 78.4 flint clay 7 7t.5 8 61.3 sandstone wedge 9 50.1 floor roof 1 74.6 2 75.4 3 35.3 4 77.8 5 70.1 flint clay 6 64.2 7 63.4 8 24.7 floor flint clay 1 72.3 2 60.5 3 45.2 roof I 67.5 2 60.7

NC NC NC NC A/5 B/5 C/5 D/5 E/5 NC E/5 G/5 G/5 H/5

A/4 B/4 B/4 C/4 D/4 E/4 G/4 G/4 NC G/4

B/2 C/2 D/2 E/2 E/2 G/2 G/2 NC

G/3 G/3 G/3 A/6 A/6

4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4930 4924 4925 4926 4927 4928 4929 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4943 4941 4942 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4987 4988 4989

VII-

PVT

FUS

SFS

MIC

MAC EX

RES

6.1

2.4

4.4

7.8

0

c~

0.7

2.8 1.7 5.9 8.2 11.7 5.6 6.2 9.9 2.4 7.4

1.7 4 4.8 6.7 2.6 4.1 18.6 1.7 26.7 2.6

2.8 9.2 8.2 10.9 5.9 10 24.7 1.8 13.8 2

0.2 5.3 6.7 6.5 3,3 3,2 5,1 3,3 0,7 2,5

0 0 0 0.1 0.1 0.1 0 0 0 0

1.4 6.9 7.2 6.8 3.1 4.8 12 4.4 5.8 5.6

0.3 0.1 0.6 0.2 0.1 0.3 0.2 0.1 0 0

3.3 3.7 0.2

3.4 6.8 3

5.9 6.7 2,2

6,5 6.2 34,9

0 0 0

4.3 6.7 16

0 0 0

3.7 2.9 4.6 1.8 0.9 3.7

8.5 5 4.5 3.8 17.6 3.1

20.5 6.4 2.2 7.2 21.6 4.1

8.7 8,7 6.1 3.5 6,3 5,4

0 0 0 0 0 0

11.3 3.3 2.9 5.5 15.9 5.3

0.1 0 0 0 0 0

2.8 5.1

5.3 7.9

4 8.5

10.6 12.1

0 0

5.8 5.1

1.2

7.3

5.1

21.7

0

14.5

0.1

6.5 0.7 1.1 7.6 12.3

3.5 4.7 15.4 1.2 1.6

3.2 7 18.9 1.3 2.5

8.5 5.8 12.2 8.2 7.8

0 0 0 0 0

3.6 6.3 17 3.8 5.7

0.1 0.1 0.1 0.1 0

5.3 3.3 0.9

4.2 7 17.2

3.8 6.2 8

16.6 13.3 20.9

0 0 0

5.7 6.6 28.1

0.2 0.2 0.2

0.7 1.8 0.9

5.4 7.5 10.1

2.5 6.5 9.5

14.9 16.6 21.6

0 0 0

4.2 7.1 12.5

0 0 0.2

1.4 0.9

3 7.7

7.7 9.3

11.1 12.8

0 0

9.3 8.6

0 0

0 0

Ash

Sulful

93.76 35.86 85.67 69.81 11.59 2.86 4,05 4.4 6.63 16.25 4.19 4.35 7,36 83.36 14.39 9.21 19.87 92.31 96.38 6.23 5.78 12.18 7.24 22.14 12.85 85.52 15.29 15.44 85.4 51.91 89.25 89.87 8.19 t3.46 22.64 5.33 7.89 85.56 11.41 8.28 54.85 93.5 85.26 12.81 13.01 31.65 83.71 18.91 7.74

0.(t2 0.6l 0.13 0.27 0.83 0.73 0.92 1.4 0.72 0.61 0.8 1.96 2.78 0.09 3.42 0,97 0.91 0.07 0.39 2.43 3.11 6.77 0.67 0.63 2.23 0.33 1.06 0.94 6.95 0.4 0.14 0.6 3.92 5.69 0.55 1.67 1.24 0.08 0.89 0.98 0.45 0.06 0.38 2. t 0.86 0.58 0.31 4.38 3.72

W.M. Andrews, Jr. et al. ~International Journal of Coal Geology 26 (1994) 95-115

101

Table 1 (cont.) Site Interval K C E R #

Bench

VIT

PVT

FUS

SFS

MIC

6 6 6 6 6 6 6 6 6 6 6 6 1 1 1 1 l 1 1 1 1 1

3 39.7 4 72.2 5 23.8 6 87.5 7 35.6 8 81.2 9 68.2 flint clay 10 59.1 11 61.1 12 63.6 13 32.5 1 54.2 2 76.7 3 56.5 4 84.8 5 39.4 6 83.5 7 66.3 flint clay 8 67.5 9 61.1

i.5 7.5 0.7 2.4 4.4 5.1 10.6

1 6 . 9 20.1 4.7 4.5 19.1 38.6 0.9 4.1 1 1 . 6 22.1 3.4 1.6 3.8 3.2

2.5 6 1.4 0.2 1 11.7 4 2.3 4.7 3.2 8.2

15.7 6.5 9.2 6.3 8 6.8 3.8 1.4 7.2 1 3 . 9 2.5 2.8 7 15.3 0.9 2.2 1 6 . 8 16.7 1.8 2.3 6.9 5.5

A/6 B/6 C/6 C/6 D/6 E/6 E/6 G/6 G/6 G/6 H/6 A/I B/1 C/I C/I D/1 E/1 E/1 G/1 G/I

4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 41000 41001 41002 41003 41004 41005 41006 41007 41008 41009 41010 41011

11,1 2.6

2.6 8.9

2.2 7.1

MAC EX

RES

Ash

Sulfur

9.1 6.8 4.8 3.1 9.8 2.8 5.4

0 0 0 0 0 0 0

12.7 4.3 13 2 16.2 5.8 8.8

0 0 0 0 0.3 0.1 0

10.9 12.7 12 50.1 10.5 3.5 8.5 6.2 6.5 5.7 5.8

0 0 0 0 0 0 0 0 0 0 0

5.3 4.7 8.2 12 13.2 2.8 8.7 3.6 15.9 3.5 7.3

0 0 0 0 0 0 0 0 0 0 0

11.5 12.9

0 0

5.1 7.2

8.99 3.45 16.71 5.62 21.78 5,51 13,24 80,58 16,86 9,89 10,47 27.58 9.25 2.91 8,22 5,18 16.04 4.89 6.54 82.74 16.96 12.34

0.53 0.69 0.7 0.8 0.57 0.83 2.75 0.07 0.68 0.88 0.82 0.78 3.36 0.65 0.81 0.71 0.6 0.76 0.8 0.07 0.77 0.83

0 0.2

NC = no correlative.

underlying peat. Elsewhere, the coal and clastics inteffinger, indicating both contemporaneous and postdepositional scenarios on a localized scale.

2. Procedure A three-entry mine unit through the Fire Clay washout belt in Perry County provided a cross-section for study of the washouts and the nearby coal (Fig. 2). The mine-through, with fewer entries and cross-cuts than a normal mine section, provided access to the coal on the south side of the channels. The coal was described in detail at six sites (Fig. 3), using the lithotype descriptions of Hower et al. (1990). All descriptions were made facing west. A total of 71 incremental samples were taken from five of these columns, with lithotype variation being used to determine sample thickness. Various thickness measurements were also taken along the 350 m north-south traverse. Determinations of ash and sulfur were obtained using ASTM methods. Maceral composition was determined using the procedures found in Stach et al. (1982). Table 1 summarizes the petrography, ash and sulfur data for samples in this study. Table 2 presents geochemical data on ashed samples of the Fire Clay coal bed.

102

14'.M. Andrews. Jr. et al. / International Journal q / ( ))a/ Geology 26 (1994) 95- 11 ."

Table 2 Ash geochemistry data KCER~ 4913 4914 4915 4916 49t7 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4987 4988 4989

SO3

0.08 9.39 5.97

MgO

Na20

Fe2()3

TiO2

SiO 2

1.64 1.93 1.88 1.83 1.07 1.11 0.26 0.31 0.20 0.25 0.07 0.09 0.00 0.07 0.20 0.98 1.52 0.52 0.42 0.21 0. I1 0.00 0.12 O. 13 0.45 0.00 0.18 0.40 0.88 1.52 0.46 0.41 0.28 0.00 0.26 0.16 0.33 0.08 O. 19 0.27 0.77 1.51 0.07 0.21 0.36 0.83 1.85 0.36 0.76

0.33 0.86 0.28 0.31 0.40 0.74 0.26 0.19 0.00 0.00 0.00 0.00 0.05 0.00 0.02 0.10 0.13 0.80 0.97 0.00 O.Ol 0.00 0. tl 0.00 0.00 0.00 0.00 0.00 0.08 0.23 0.52 0.78 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.00 0.23 0.25 0.22 0.00 0.00 0.12 0.28 0.34 0.24

5.46 6.36 5.34 5.06 3.72 7.92 11.98 25.63 3.71 2.37 3.82 35.00 0.32 23.87 3.97 5.53 4.57 42.34 2.62 39.42 53.59 65.73 2.89 1.49 17.84 1.08 4.49 3.44 2.69 4.50 17.3t 11.81 57.31 54.41 1.00 28.86 9.24 0.91 2.07 2.98 2.10 5.18 0.97 13.71 2.29 2.57 5.51 49.17 24.73

1.17 1.08 1.03 1.05 1.08 1.16 1.52 0.67 1.57 2.83 1.26 1.21 1.37 1.00 2.39 1.15 0.94 0.94 0.73 1.71 0.51 0.27 1.61 2.40 1.16 1.55 1.58 1.18 1.19 0.92 0.51 0.39 0.47 0.84 2.63 0.83 1.49 1.29 1.20 1.31 1.70 0.97 1.45 1.18 1.49 1.55 1.01 0.54 0.73

60.12 64.47 59.30 57.48 54.02 47.00 46.73 25.20 48.08 64.24 48.89 35.00 53.60 41.21 56.97 56.00 59.00 28.21 84.50 32.50 17.90 13.87 52.04 72.01 42.73 52.75 51.56 54. t I 64.17 59.55 66.59 75.23 19.51 25.36 73.35 33.52 52.60 55.67 56.7 l 54.67 64.16 62.67 53.79 47.92 57.81 64.40 59.68 20.46 38.36

CaO 0.46 0.95 0.25 0.30 0.81 3.19 3.61 8.82 5.31 1.56 2.07 1.11 0.43 0.73 2.40 0.79 0.21 2.44 0.51 2.55 4.78 3.99 6.49 1.29 7.32 0.38 2.89 2.55 0.26 0.26 0.51 0.90 3.08 1.43 1.04 4.15 1.27 0.36 1.26 1.34 0.20 0.29 0.34 1.42 0.97 0.42 0.23 9.11 5.97

K20

[:'205

AI2()3

Mo

4.43 4.03 5.10 5.19 3.85 2.22 0.71 0.31 0.40 1.84 0.53 1.49 0.43 0.95 1.41 4.12 4.82 0.69 1.41 0.60 0.21 0.17 0.38 1.49 1.22 0.42 0.74 1.70 4.58 4.65 1.39 1.21 0.62 0.18 1.76 0.48 1.54 0.49 0.88 1.49 4.26 4.30 0.50 0.79 1.81 3.83 4.93 0.27 3.07

0.08 O. 15 0.05 0.05 0.07 0.07 0.09 0.09 0.13 O. 11 0.15 0.14 0.10 0.14 0.10 0.08 0.05 0.29 0.11 0.09 0.06 0.05 0.74 0.08 0.16 O. 10 0.22 0.08 0.04 0.04 0.06 0. ll 0.06 0.05 0.10 0.08 0.16 0. t2 0.27 O. 12 0.05 0.04 0.13 0.20 0.12 0.05 0.04 0.04 0.05

25.92 20.42 27.00 29.25 33.89 34.63 32.55 25.20 32.38 24.15 40.69 24.61 44.63 32.09 31.03 3t.62 28.46 2173 8.27 19.93 16.02 9.27 30.27 20.05 21.77 42.45 33.90 32.38 25.31 26.10 11.03 6.44 14.06 15.16 18.01 26.77 30.67 39.07 34.80 35.90 25.98 22.87 42.21 32.44 33.60 25.58 24.34 11.23 18.69

0 t2 14 17 24 48 26 32 27 25 5l 2 21 10 22 22 14 53 25 0 39 37 22 11 1 7 1 32 18 18 27 29 25 25 8 34 3 22 0 46 14 13 19 0 30 18 20 24 22

W.M. Andrews, Jr. et al. / International Journal of Coal Geology 26 (I994) 95-115

Mn

Rb

Sr

103

KCER#

Zn

Cu

Ni

Co

Cr

Ba

V

Zr

4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4987 4988 4989

248 148 101 122 194 103 109 20 21 110 53 90 53 387 117 530 97 103 31 238 243 16 42 122 100 5 530 180 65 105 19 17 49 167 59 166 69 78 312 232 95 206 39 396 254 146 124 95 97

224 50 67 80 347 314 235 144 142 143 162 253 34 132 482 221 54 64 41 266 100 1 118 119 154 41 103 176 107 72 37 0 2 31 97 168 149 42 115 302 92 33 46 127 176 137 64 140 90

279 39 56 59 140 277 156 157 73 20 117 141 20 126 84 237 38 79 15 560 202 24 55 16 123 19 149 85 37 47 23 24 276 70 16 157 115 14 90 130 32 49 11 149 75 76 45 116 89

42 24 21 22 48 89 50 67 18 8 27 87 0 73 27 64 16 114 7 128 117 136 12 2 48 1 40 16 11 17 47 31 131 98 2 57 39 1 25 33 7 20 0 50 17 17 20 115 62

244 47 73 87 113 111 92 52 129 149 116 78 0 62 110 169 66 56 15 560 43 4 107 133 45 0 62 105 85 72 6 0 76 55 116 82 63 0 86 130 89 53 0 61 96 92 79 29 66

940 800 960 960 1020 1930 1220 1180 1020 700 1190 740 700 650 980 1080 900 690 395 970 1060 491 1360 610 640 670 760 730 940 900 366 339 1040 550 650 970 830 600 680 860 870 860 710 850 840 890 990 1000 830

880 129 170

297 840 361

570 466 670

1310 600 920

910 640 462

433 301 223 170 190 210 236 198 65 207 298 355 154 159 68 570 148 68 168 167 192 66 230 296 167 155 55 71 302 112 159 189 211 58 225 352 179 133 68 198 273 192 188 118 215

10 322 0 213 111 447 37 0 0 0 35 164 310 185 380 0 9 62 200 113 580 48 86 202 148 295 377 1941 43 0 61 0 0 11 0 21 0 249 6 0 0 0 330 86 136

530 231 22 0 0 274 13 143 4 38 131 510 680 0 162 0 0 0 0 234 127 0 0 241 720 680 98 101 0 0 372 0 243 0 0 219 780 580 0 0 248 580 650 0 253

2980 9400 6570 5980 6610 1620 5390 1800 910 1270 3870 2170 710 1610 324 2930 3580 1390 15900 1500 2220 830 2440 2210 890 720 186 234 3210 1580 1590 4570 3180 910 2650 3180 770 479 910 2930 3140 1390 760 2700 1520

680 1060 1050 680 1320 1260 1080 2070 1410 2280 1590 660 429 447 1560 770 336 112 1990 1280 2950 1590 5700 1250 670 410 306 384 360 230 1400 770 5280 1470 4560 1090 840 550 1440 4710 1680 850 441 280 272

W.M. Andrews, Jr. et al. / International Journal of Coal Geology 26 (1994) 95-1t5

104

Ta KCER# 4990 4991

4992 4993 4994 4995 4996 4997 4998 4999 41000 41001 41002 41003 41004 41005 41006 41007 41008 41009 41010 41011

2 (b

cI

oe

~

t

i

~

i~,

c

d

SO3

MgO

Na20 Fe203

TiO2

SiO2

CaO

K20

P205

A1203

Mo

8.07 10.44 0.34 3.19 0.09 5.03 16.77 0.04 7.63 1.58 0.54 0.23 7.34 10.24 3.71 4.08 1.27 1.20 9.20 0.00 0.25 0.64

1.37 1.44 0.11 0.89 0.39 0.83 0.97 0.12 1.86 0.77 0.35 1.25 0.13 0.88 0.43 0.88 0.39 0.36 0.56 0.00 0.13 0.53

0.00 2.32 3.77 1.09 0.08 0.36 0.02 0.14 0.00 0.00 0.00 0.02 0.02 0.50 0.00 0.18 0.00 0.05 0.00 0.16 0.00 0.12

1.84 0.88 2.04 1.29 2.45 1.18 0.79 1.35 0.74 1.43 2.85 1.11 1.16 0.70 2.04 1.11 2.59 1.30 1.28 1.55 1.21 1.31

55.16 36.94 65.74 49.34 73.05 48.49 30.03 58.30 39.79 55.84 65.60 59.59 29.80 34.73 56.40 43.92 67.16 53.94 44.15 57.80 57.00 57.97

10.81 10.60 0.75 4.25 0.48 6.08 14.48 0.50 19.42 2.23 1.17 0.64 6.60 13.52 4.66 5.48 2.06 2.20 11.33 0.46 0.86 1.46

0.25 0.49 0.33 0.40 1.69 0.66 1.13 0.47 0.62 1.62 0.77 4.09 0.28 0.34 0.47 0.45 1.96 0.80 1.48 0.44 0.85 2.02

0.07 0.18 0.08 0.08 0.09 0.13 0.09 0.10 0.18 0.17 0.14 0.06 0.35 1.07 0.57 3.51 0.10 0.14 0.17 0.13 0.17 0.08

18.64 25.96 22.19 30.83 19.14 30.33 16.97 36.20 25.63 32.21 24.06 25.80 10.88 30.39 23.99 32.11 21.27 34.90 26.29 36.84 35.87 31.89

16 49 11 34 21 35 25 2 2 41 20 24 21 41 19 28 22 30 11 4 6 36

3.14 8.68 2.84 6.66 1.51 5.09 20.22 0.84 2.16 2.22 2.56 5.29 41.41 7.08 5.75 5.91 1.60 3.13 3.55 0.70 1.97 2.04

3. Discussion

3.1. Fire Clay coal The sandstone interrupts the seam twice in the cross-section (Fig. 2 ), with an area of disturbed coal between the sandstone bodies. Sandstone is the dominant lithology of the bodies, but siltstone and claystone are present in minor amounts. Numerous north- and south-dipping shear planes are present within the sandstone bodies. The exposed contacts with the coal are abrupt, with no intertonguing of the sandstone and coal. The coal bed gradually rises nearly 4 m toward the south in the study area and the disturbed coal between the sandstone bodies occurs somewhat above the floor plane of the coal, outside the sand belt. North of the channel, the coal thickens towards the interruption, increasing 0.5 m from site 6 (samples KCER-4987 to KCER-41001 ) to site 5 (samples KCER4913 to KCER-4930). The coal is underlain by a dark gray clay. A cannel coal (KCER-4928 and KCER-41001 ), 4-7 cm thick, is present at the base of the coal and is continuous northward out of the study area. Cannel coal was not found at any of the sites within or south of the sandstone belt. The bottom bench of the coal bed, which is underneath the flint clay tonstein, contains alternating bright (bright clarain and claxain) and dull zones (dull clarain and durains) and thickens from 33 cm to 40 cm toward the channel.

W.M. Andrews, Jr. et al. / lnternational Journal of Coal Geology 26 (1994) 95-115

KCER#

Zn

Cu

Ni

4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 41000 41001 41002 41003 41004 41005 41006 41007 41008 41009 41010 41011

50 52 49 77 44 59 138 56 282 246 153 314 37 30 12 42 120 157 95 46 246 240

137 139 73 118 89 160 62 23 40 168 411 158 89 127 111 81 138 149 157 32 109 234

31 110 25 103 17 102 88 16 67 87 78 154 53 113 45 77 20 113 89 12 108 206

Co 9 39 6 28 4 28 53 0 17 23 21 42 94 37 17 21 5 22 23 0 29 44

Cr

Ba

V

95 70 98 113 135 111 37 0 13 96 109 133 55 51 110 92 130 114 77 0 75 175

870 3230 920 2020 960 1730 720 680 690 1010 1150 1040 960 3110 1410 3580 750 1230 830 620 850 810

154 190 107 232 178 238 150 61 156 305 263 283 151 195 148 198 186 236 200 63 218 496

Mn 471 180 0 0 6 93 96 0 401 0 0 209 141 244 74 370 102 0 890 19 85 109

105

Rb

Sr

Zr

0 10 4 11 317 31 115 0 0 159 5 530 0 9 8 41 344 43 176 0 6 336

6540 12100 1840 7600 1520 6600 3450 1190 7110 3640 5850 1920 3710 23800 12700 2990 1930 6880 4420 1050 2610 2480

1420 1360 1210 1200 1170 1380 1530 1680 3780 1590 2160 660 477 2260 1910 150 1240 1480 3910 1830 4540 990

Within the upper bench, a series of prominent durains and dull zones can be traced to and across the sandstone bodies (Fig. 3). A thin dull clarain rests directly above the tonstein and is followed upward by a bright lithotype sequence with pyrite lenses and fusains. This sequence thickens from 34 cm to 45 cm towards the interruption. This zone is overlain by the first prominent durain. The bright zone between the first and the second durain also thickens toward the south (16.5-21 cm), as does the bright lithotype zone between the second and third durain (25.5-28 cm). The coal bed is overlain by gray silty sandstone. The coal north of the sandstone belt does not show signs of deformation or disturbance, although the actual contact with the sandstone has been mined away. Due to safety concerns, the walls of other entries were not examined. The coal bed between the sandstone bodies, however, is quite disturbed, with highly variable thicknesses, contorted bedding, slickensided shear planes and repeated sections. At site 4 (samples KCER-4931 to KCER-4943 ) (Fig. 4), banding in the coal is truncated by overlying sandstone and the coal bed is offset across a slickensided shear plane near the base of the seam. The coal bed is underlain by a hard gray clay that softens downward. The bottom bench comprises mainly dull lithotypes, with a thin, 2 cm sandstone wedge within it. The tonstein at this site is thinner than at other sites: only 8.5 cm, compared to > 14 cm outside the sandstone belt. Immediately adjacent to the shear plane the parting is even thinner and is somewhat contorted (Fig. 4). The sequence of bright and dull lithotypes

106

W.M. ,4ndrews, Jr. et a! / International.lournal ~!( "oal Geolog5l, 26 (1 •94) 95- I 15

Fig. 4. Photograph of relationships at site 4 (samples KCER-4931 to KCER-4943 t. Note displacement oftonstein ( t ) along slickensided surface.

is similar to that north of the channel, but the interval between durains is thinner, and the section is topped by a 17 cm dull zone, with banding truncated by the sandstone. Site 2 (samples KCER-4944 to KCER-4954) shows dramatic disturbance of the seam (Fig. 5 ), with a repeated section and erratic thicknesses. The coal bed is pinched out along a shear plane, which is overlain by a clay wedge, which, in turn, is overlain by another 'mat' of the Fire Clay coal bed. The tonstein within the mat thins toward the truncated end. Beneath the shear plane, another wedge of coal, resembling the base of the Fire Clay coal bed, is present (see Geochemistry section). The floor is gray clay and the roof is sandstone. The lithotype succession at this site is similar to site 5, with the upper bench truncated between the second and third durains above the flint clay (Fig. 3 ). Only the bottom bench of the overlying mat in the doubled section (site 3: samples KCER-4955 to KCER-4958 ) (Fig. 5 ) was accessible for description and sampling. Directly beneath the tonstein the dominant lithotype is clarain, with the base of the bed being durain. At the southern edge of the southern sandstone body the abrupt contact with the coal bed is well exposed (Fig. 6 ). The flint clay parting is separated into isolated 'lumps' along a shear plane within the coal. Due to the nature of the shear plane, the description of the coal had to be made in an offset manner; care was taken to ensure accurate measurements. The lithotype successions and thick-

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107

Fig. 5. Photograph of relationships at site 2. The coal bed is doubled at this site - - note the two locations of the tonstein (t) - - separated along a slickensided clay layer (c). Samples KCER-4944 to KCER-4954 collected in the center of the photo. Samples KCER-4955 to KCER-4958 collected out of view to the right.

nesses at site WS 1 (Fig. 2 ) are more similar to that of site 5 than to the coal bed found between the sandstone bodies. A 3 cm thick durain is found at the base of the coal bed (the basal cannel observed north of the channel is not present). The remainder of the lower bench consists of clarain. The upper bench is remarkably similar to site 5, with the only distinct variation being apparent toward the top (Fig. 3 ). The coal bed is underlain by clay and overlain by sandstone. Further south, at site 1 (samples KCER-41002 to KCER-41011 ), the coal bed returns to what may be considered a 'normal' section, similar to that at site 6 (Fig. 3). At this site the basal durain seen at WS1 is absent and the lower bench is entirely clarain. The tonstein is somewhat thinner here ( 12 cm) and the upper bench is similar to that of WS l, although the brighter lithologies between durains are thinner. As at site WS l, the roof is sandstone and the floor is clay.

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t! ~,~,1.,4 ndrews. .h. eta/. / lmernattonal Journal c~/( 'oal Geolog) 26 r1994) 95- / ] 5

Fig. 6. Photograph of relationships at site WSI. The tonstein (t) is split along the slump plane, with remnant 'dragged' along slump surface,

3.2. Flint clay lenses At site 1 a thin lens of hard clay, very similar to the tonstein, was collected just below the main tonstein (Fig. 7). The lens, approximately 1 cm thick and 6 cm wide, is exposed in the coal bed 2.1 cm below the main tonstein. A zone of small 'microlenses', identified using reflected light microscopy, is present above and on either side of the lens. Another, smaller, lens ( 1 mm thick, 8 mm wide) is present 1 cm below the upper lens. SEM investigations indicate that the dominant mineral in the lenses is kaolinite, the dominant Fire Clay tonstein mineralogy. Microphenocrysts were not observed in these lenses. Lenses such as these have not been mentioned in any previous literature on the Fire Clay coal bed and were not observed at other sites in the study area.

3.3. Statistical significance of lithologies Statistical analysis of the samples indicates that the variation in maceral composition, ash and sulfur is vertical, rather than lateral. Samples were grouped into 'intervals' that could be traced laterally across the study area (Fig. 3) and the calculated values for these intervals were compared using the chi-squared test of difference. (Values from each sample were weighted according to thickness when calculating values for each interval. ) Tables 3 and 4 show the results of the statistical tests.

IV.M. A ndrews, Jr. et al. / In ternational Journal of Coal Geology 26 (1994) 95- I 15

109

i

Fig. 7. Photograph of small kaolinite-rich lens (t) found below the main tonstein parting (not included in block, but occurring at the top of the coal). Smaller kaolinite lenses (k) occur betweenthe main flint claytonstein and the lens (t). Intervals on scale at left are l cm. The chi-squared value for each interval was well within the critical limits of the test. Interval A showed the highest value but was still within the limits for similarity at the 95% significance level. The higher level of variation in A may result from the influence of sandstone deposition (e.g., erosion and oxidation). The results showed that much of the vertical variation is associated with the durain layers. Interval D, the first distinct durain above the tonstein, constitutes a significant portion of the chi-squared value of vertical difference at each site. Other durains were not isolated as intervals, due to sampling difficulties, but interval C, the top of which is the second distinct durain, significantly contributes to the total chi-squared value, possibly as a result of the durain layer. The thickness oflithotypes does differ across the area, as shown in Fig. 3. When considering only the columns outside of the washout belt, a clearly lobate crosssection is found, but when the samples from the disturbed section are considered the picture becomes more complex. The interior sites may be of differing thickness due to slumping (discussion below).

110

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Table 3 Lateral statistical summary KCER#

VIT

PVT

FUS

SFS

MIC

EX

Ash

Sulfur

X2 totals

a/6 a/5 a/4 a/l X2totals b/5 b/4 b/2 b/6 b/1 X2 totals c/5 c/4 c/2 c/6 c/1 X2totals d/5 d/4 d/2 d/6 d/1 X2totals E/5 E/4 E/2 E/6 E/1 X2totals G/5 G/4 G/2 G/3 G/6 G /I X2totals H/5 H/6 X2totals

0.090 0.627 1.038 0.000 1.761 0.032 0.068 0.000 0.086 0.05t 0.238 0.267 0.041 0.014 0.018 0.087 0.428 0.255 0.059 0.024 0.011 0.276 0.625 0.056 0.015 0.103 0.000 0.002 0.176 1.023 0.106 0.000 0.633 0.157 0.000 1,920 0,823 0,823 1,646

1.709 6.373 0.013 1.773 9.868 1.445 2.356 0.370 0.068 1.445 5.684 3.542 0.235 1.368 0,074 0.002 5.222 2.170 1.894 1.610 0.255 0.444 6.373 0.462 1.381 1.225 0.012 0.520 3.599 0.016 0.000 0.014 1.850 0.001 1.735 3.617 0.000 0.000 0.000

0.792 0.000 0.465 0.033 1.290 0.236 0.331 0.004 0.319 0.349 1.239 0.063 0.002 0.261 0.000 0.668 0.994 0,423 0.160 0.022 1.210 0.40 1.855 0.108 0.046 0.688 0.231 0.214 1.287 0,374 0,056 0.170 0,093 1,740 0,132 2,565 0.047 0,047 0.094

2.535 0.392 4.074 0.040 7.041 0.795 0.000 0.196 0.040 0.410 1.440 0.682 0.033 0.065 0.407 1.052 2.240 0.731 0.031 0.174 0.081 0.808 1.825 0.218 0.760 0.273 0.095 0.181 1.528 0,032 0,000 0,061 0.054 0,050 0,169 0.367 0.089 0.089 0.178

0.217 0.710 0.012 0.238 1.177 1.127 0.328 1.176 0.147 0.958 3.736 0.379 0.225 0.372 0.291 1.039 2.305 1.039 0.354 2.232 0.415 0.274 4.314 1.017 0.012 1.613 0.396 0.066 3.105 2,984 0.098 0.354 2,525 0,013 0,000 5.975 1.359 1.359 2.718

0.384 0.842 0.232 1.112 2.570 0.014 0.033 0.024 0.229 0.111 0.410 0,000 0,036 0,349 0,365 0.036 0.787 0.710 0.000 0.161 0.062 0.000 0.933 0.011 0.000 0.086 0.455 0.062 0.615 0.064 0.126 0.001 0.653 0.056 0.000 0.900 0.286 0.286 0.571

2.486 0.413 1.947 1.069 0.390 0.009 0.197 0.235 df=15:23.71 (pet) 5.020 1 . 7 2 6 df=21:30.45 (pas) 0.278 0.390 2.380 3.268 1.137 1.033 0.860 1,181 1.332 1 . 2 3 8 df=20:12.7 (pet) 5 .9 8 7 7,110 df=28:25.84 (pas) 0.265 0,580 0.090 0,640 3 .5 5 5 9.175 0.069 0.508 0.652 0.569 df=20:12 (pet) 4.632 11.473 df=28:28.08 (pas) 0.627 0.00 0.284 0.002 0.417 0.003 0.204 0.000 0.704 0.000 df=20:15.9 (pet) 2.236 0.006 df=28:18.17(pas) 0.435 0.064 3.299 0.269 0.233 0.006 0.027 0.003 0.703 0 . 4 1 1 df=20:10.3 (pet) 4.697 0.752 df=28:15.76(pas) 0.450 0.630 0.192 0.008 1.366 0.022 2.984 0.000 0.248 0.077 0.030 0 . 0 8 1 df=25:15.3 (pet) 5.271 0.818 df=35:21.43(pas) 0.626 0.005 0.626 0.005 df=5:5.21 (pet) 1.253 0.010 df=7:6.47(pas)

pet = analysis of petrographic data only; pas = analysis of pet rographic, ash, and sulfur data; df= degrees of freedom.

3.4. Sandstone washouts Field observations and map relationships indicate that sandstone interruptions in the Fire Clay coal bed are a result of post-depositional fluvial processes. This is supported by the abrupt contacts between the sandstone and coal bed, the lack

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111

Table 4 Vertical statistical summary Interval

VIT

PVT

Sulfur

X2totals

a/l b/1 c/1 d/l e/1 g/l X2 totals b/2 c/2 d/2 e/2 g/2 X2 totals a/4 b/4 c/4 d/4 e/4 g/4 X2 totals a/5 b/5 c/5 d/5 e/5 g/5 h/5 X2 totals a/6 b/6 c/6 d/6 e/6 g/6 h/6 X2 totals a/avg b/avg c/avg d/avg e/avg g/avg X2 totals

1.84 2.05 2.94 10.18 2.42 0.02 19.45

3.41 0.11 4.85 8.07 2.36 3.17 1.26 2.82 1.08 0.05 1 7 . 0 3 10.29 0.02 1.29 2.48 0.25 0.01 1.03 1 3 . 0 6 2 3 . 6 1 22.92

1,17 2,16 0,10 0.14 0.43 3.02 7.02

3.46 0.01 3.34 4.09 1.38 1.12 7.95 5.57 1.27 1.39 0.31 3.26 1 7 . 7 0 15.45

4.23 0.22 0.16 0.27 0.13 0.11 5.10

df=25:104 (pet) df=35:124 (pas)

1.51 1.77 13.36 1.48 0.02 18.14

1.01 1.17 2.26 3.10 0.36 0.01 2.47 1 3 . 6 9 18.71 6.25 3.76 4.07 0.03 0.01 0.50 1 2 . 8 7 1 8 . 9 8 25.55

0.17 1.64 0.58 0.32 2.25 4.96

2.06 0.21 11.59 1.17 0.19 15.21

1.22 0.17 9.37 2.60 0.57 13.93

0.78 3.99 1.54 0.42 0.98 7.72

df=20:95.8 (pet) df=28:117 (pas)

0.18 9.30 0.95 3.99 1.72 1.08 1 4 . 2 3 11.48 2.47 3.97 0.11 1.98 1 9 . 6 6 31.80

0.37 0.00 1.81 0.09 0.40 2.52 5.19

1.69 2.91 2.84 0.67 0.67 2.01 8.48 8.12 0.79 0.04 0.67 0.82 1 5 . 1 3 1 4 .5 8

0.08 4.82 0.90 0.95 0.02 0.51 7.29

df=25:98.9 (pet) df=35:121 (pas)

0.03 2.00 1.56 13.43 4.84 1.75 5.44 29.04

0.59 0.07 0.47 4.68 1.92 0.99 0.07 0.61 0.15 0.00 2 5 . 3 1 28.35 0.80 2.53 5.45 1.20 0.07 0.69 5.89 1.60 5.00 1 3 . 2 2 3 2 . 1 2 41.10

0.64 3.51 3.64 1.61 4.08 0.74 76.20 90.42

0.08 3.35 2.68 2.95 0.92 1.01 2.53 4.30 0.91 1.50 0.52 0.22 8.73 1 0 . 4 4 1 6 . 3 7 23.77

0.06 0.03 0.19 0.29 0.40 0.45 0.07 1.51

df=30:222 (pet) dr=42:248 (pas)

0.07 2.98 5.90 9.25 5.28 0.09 11.87 35.43

1.94 0.44 0.01 3.78 0.30 1.30 0.68 0.89 0.44 0.12 5.07 27.31 2.91 1.05 3.92 0.00 3.41 0.18 3.35 0.84 5.10 1 2 . 7 9 1 2 . 0 0 38.26

0.80 0.01 0.05 3.51 1.83 7.25 7.85 2.43 2.63 1.13 8.51 5.49 7.31 0.19 1.89 0.22 0.69 0.14 96.16 1.80 1 5 .5 0 116.98 1 5 . 4 6 3 2 . 9 5

4.46 0.25 0.17 0.37 0.05 0.15 0.18 5.64

df=30:231 (pet) df=42:270 (pas)

0.52 0.30 0.00 0.69 0.00 0.19 1,69

df=25:88.2 (pet) df=35:103 (pas)

4.52 2.53 3.03 10.97 3.12 0.12 24.29

1.34 1.81 2.42 12.04 2.79 0.00 20.40

0.19 0.26 0.45 1.43 0.19 0.25 2.77

0.32 2.64 0.97 0.34 0.87 0.18 5.32

FUS

SFS

0.00 1.88 1.38 2.72 1.29 0.20 1 3 . 1 5 15.17 2.30 4.52 0.03 1.08 1 8 . 1 5 25.57

MIC

0.32 0.35 1.19 0.03 0.73 3.22 5.83

EX

Ash

0.68 0.60 2.30 2.24 0.84 0.55 8.20 8.22 0.66 0.71 0.19 0.97 12.88 13.29

pet = analysis of only petrographic data; pas = analysis of petrographic, ash, and sulfur data; df= degrees of freedom.

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of any tidal laminations in the clastic deposits and the general lack of inorganic partings in the coal bed (aside from the tonstein ). Elsewhere in the region (point Z, Fig. 1 ), mine data indicate splitting of the coal bed proximal to a channel, which could indicate contemporaneous channel development. This introduces the possibility of multiple episodes of channelling, beginning during the development of the peat-forming swamp and continuing until after peat deposition had ceased. The sandstone bodies are inferred to be deposits in small channels cut into the coal bed during periods of high water velocity (e.g., floods or crevasse splays). The extensive nature of the sandstone overlying the coal, as well as the recurrence of numerous subparallel, discontinuous washouts in the region (Fig. 1 ), indicates a major fluvial system. The channelling in the study area may also have been influenced by the compaction of the locally thicker area of peat. However, regional trends suggest that this was not a widespread control on channel placement. Outside the study area the sandstone body overlies coal beds of varying thickness, as well as areas where no coal is present. The disturbed coal between and south of the washouts can be explained by compaction-induced or bank collapse slumping of the peat and sand. The changes in the thickness of the tonstein parting and the undisturbed banding of the coal indicate placement of the washouts between the early stages of diagenesis and induration of the tonstein. The weight of later sediments could have caused deformation of the soft sediment and may explain the slickensides, slumping and thrusting of the coal bed. The minor differences in petrography, lithotype succession and thickness in the area between washouts could be related to the topographically higher position of this area relative to the coals outside the washout belt. Peat accumulating in topographically higher areas would be subjected to more aerobic activity and degradation; therefore the accumulations of peat would be thinner. Climatic fluctuations could also have influenced the vertical reoccurrence of the prominent durains throughout the study area, by causing changes in water levels as well as the aerobic content of the water. The sulfur distribution at site 5, being relatively low throughout the upper bench, differs from the typical increasing-upwards trend seen elsewhere in the region. This may be a result of fluids moving through the peat in the vicinity of the channels, either during or after sandstone deposition.

3.5. Geochemistry The ash geochemistry of the Fire Clay coal bed in the vicinity of the sandstone washout exhibits several interesting trends. Further discussion of the geochemistry of the Fire Clay coal bed throughout the region can be found in Hower et al. (1994). The repeated section (KCER-4955 to KCER-4958) and the underlying section, in particular the correlative section beneath the tonstein, show remarkable similarity. Compare the geochemistry; notably Sr and Zr, of KCER-4951 with

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113

KCER-4956, KCER-4952 with KCER-4957, and KCER-4953 with KCER-4958. To the best of our ability, the sampling of these lithotypes was carried out in a manner which properly represented the correlatable portions of the two sections. The similarity in geochemistry bears out the observed lithologic similarity and assists in confirming the original proximity of the portions of the doubled section. The three basal lithotypes of the KCER-4931 section (KCER-4939 to KCER4941 ) also resemble the latter two sets, although the differences in concentration are greater between the sites than within the doubled site. Some semblance of this trend can be seen as well in the KCER-4913 section to the north of the channel; the basal lithology is different, however. The Na20 content of the KCER-4991 to KCER-4993 sequence in the KCER4987 section is high compared to other lithotypes. The upper lithotypes in the KCER-4913 section (65 m to the south) are high, but not at the same level. CaO and MgO are also generally higher in the upper lithotypes in the north. There is a possibility that the concentration of certain elements may be related to fluid gradients established as the peat was disrupted by the sandstone channels. Similar arguments could be made for KCER-41005 and KCER-41003 in the KCER-41002 section, where Sr, Ba and P205 reach the highest levels of any samples in this study. The whole-coal pellets were searched by SEM-EDAX for phosphate minerals without success. The lithotypes are generally higher in Zr than is typical for eastern Kentucky coals (compare with the Pond Creek and Blue Gem coal beds, Hower and Bland ( 1989 ) and Hower et al. ( 1991 ), respectively). The highest concentrations are found in the lithotypes adjacent to the tonstein; which is not surprising as zircons are commonly found as accessory minerals in this altered air-fall volcanic ash deposit (Lyons et al., 1992 ). The persistence of relatively high Zr levels, probably from zircon, throughout the lithologic section may be a function of the reworking of mineral matter by rooting or continued minor ash falls into the Fire Clay mire.

4. Summary The above discussion can be summarized as follows: ( 1 ) Postdepositional sandstone bodies exposed in the mine-through have disturbed an apparently lobate body of the Fire Clay coal bed as slumping of the rapidly accumulating sand led to the disruption of the peat (e.g., by thrusting and slickensides, among other features) between and to the south of the washout bodies. (2) The thicker area of peat in the study area may have been a local control on fluvial channel placement. (3) A thin lens of material, very similar in kaolinite content to that of the tonstein parting, was found just below the main tonstein parting at a site south of the channels. (4) Prominent, laterally continuous, durains observed in the upper bench of

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the coal bed contribute significantly to the vertical statistical variation of coal quality factors. Lateral variation is not significant at this scale (350 m ). (5) The ash geochemistry of the basal lithotypes of the repeated section within the channel show similarities in their minor element concentrations. The high concentrations of Na20, CaO, MgO, P205, Ba and Sr in lithotypes on the flanks of the channel suggest that fluids were mobilized during compaction and slumping of the peat body and may have served to emplace those elements.

Acknowledgements The authors thank Dan O'Canna of the Kentucky Department of Mines and Minerals for assistance with mine map evaluation, Steve Greb of the Kentucky Geological Survey for assistance in field work and sedimentological interpretation, Whitaker Coal Company for information and free access within the mine, and John Ferm for helpful comments on the statistical portion of this paper. Paul Lyons and Jay Close provided critical reviews of the manuscript.

References Bohor, B. and Triplehorn, D.M., 1981. Volcanic origin of the flint clay parting in the Hazard No. 4 (Fire clay) coal bed of the Breathitt Formation in eastern Kentucky. In: J.C. Cobb, D.R. Chesnut, N.C. Hester and J.C. Hower (Editors), Coal and Coal-bearing Rocks of Eastern Kentucky. Annu. Geol. Soc. Am. Coal Division Guidebook (Field trip November 5-8, 1981 ), Kentucky Geol. Surv., Lexington, KY., p. 49-54. Chesnut, D.R., 1983. Source of voIcanic ash deposit (flint clay) in the Fire Clay coal of the Appalachian basin. C. R. l 0th Congr. Int. Strat. GEol. Carbonif~re (Madrid), 1:145-154. Eble, C.E, Hower, J.C. and Andrews, W.M., Jr., 1994. Paleoecology of the Fire Clay coal bed in a portion of the Eastern Kentucky coal field. Palaeogeogr. Palaeoclimatol. Palaeoecol., 106: 287305. Guion, P.D., 1987. The influence ofa palaeochannel on seam thickness in the Coal Measures of Derbyshire, England. Int. J. Coal Geol., 7: 269-299. Hower, J.C. and Bland, A.E., 1989. Geochemistry of the Pond Creek Coal Bed, Eastern Kentucky Coalfield. Int. J. Coal Geol., I 1: 205-226. Hower, J.C., Esterle, J.S., Wild, G.D. and Pollock, J.D., 1990. Perspectives on coal lithotype analysis. J. Coal Quality, 9(2): 48-52. Hower, J.C., Rimmer, S.M. and Bland, A.E., 1991. Geochemistry of the Blue Gem Coal bed, Knox County, Kentucky. Int. J. Coal Geol., 18:211-23 I. Hower, J.C., Andrews, W.M., Jr., Wild, G.D., Eble, C.F., Dulong, F.T. and Salter, T.B,, 1994. Coal quality trends for the Fire Clay coal bed, southeastern Kentucky. J. Coal Quality, in press. Kertis, C.A., 1985. Reducing hazards in underground coal mines through the recognition and delineation ofcoalbed discontinuitiescaused by ancient channel processes. U.S. Bur. Mines RI 8987. Lyons, P.C., Outerbridge, W.F., Triplehorn, D.M., Evans, H.T., Jr., Congdon, R.D., Capiro, M., Hess, J.C. and Nash, W.P., 1992. An Appalachian isochron: A kaolinized Carboniferous air-fall volcanic-ash deposit (tonstein). Geol. Soc. Am. Bull., 104:1515-1527. Nelson, W.J., 1983. Geologic disturbances in Ulinois coal seams. Ill. State Geol. Surv. Circ., 530: 147.

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Potter, P.E. and Simon, J.A., 1961. Anvil Rock Sandstone and channel cutouts of Herrin (No. 6) coal in west-central Illinois. Ill. State Geol. Surv. Circ., 314: 1-12. Stach, E., Mackowsky, M.-Th., Teichmiiller, M., Taylor, G.H., Chandra, D. and Teichmiiller, R., 1982. Stach's Textbook of Coal Petrology. Borntraeger, Berlin, 3rd ed., 428 pp. Weisenfluh, G.A. and Ferm, J.C., 199 I. Roof control in the Fireclay coal group, southeastern Kentucky. J. Coal Quality, 10(3 ): 67-74.