xt7qrf5k9x4t https://exploreuk.uky.edu/dips/xt7qrf5k9x4t/data/mets.xml Moore, Philip North, b. 1849. 1877  books b96-12-34887752 English Stereotyped for the Survey by Major, Johnston & Barrett, Yeoman Press, : [Frankfort, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Geology Kentucky. Coal Kentucky. Report on the geology of the Nolin River district  : embracing portions of Grayson, Edmonson, Hart, and Butler counties / by P.N. Moore. text Report on the geology of the Nolin River district  : embracing portions of Grayson, Edmonson, Hart, and Butler counties / by P.N. Moore. 1877 2002 true xt7qrf5k9x4t section xt7qrf5k9x4t 

         N. S. SHALER, DIRECTOR.








          BY P. N. MOORE.


79 A So

 This page in the original text is blank.



Professor N. S. SHALER, Director Kentucky Geological Survey:
I herewith transmit my report upon the geology of that por-
tion of the western coal field between Green river and the
Louisville, Paducah and Southwestern Railroad, lying east of
Bear Creek. The limits of the work have been determined
more by geological and topographical boundaries than by
political divisions. It therefore embraces portions of Butler,
Grayson, Edmonson, and Hart counties, without including the
whole of any of them.
I desire here to acknowledge the valuable assistance ren-
dered to the Survey by Mr. John R. Procter. In addition to his
services in the field, Mr. Procter has been of great assistance
in preparing the cross-sections which accompany this report.
His observations have been extensively used in their construc-
                Respectfully submitted,
                              P. N. MOORE, Asssistant.
   VOL. I. -6  


              AND BUTLER COUNTIES.

  The area covered by the present report consists of that por-
tion of the western coal field, and the immediately surrounding
country, which lies east of Bear Creek, between Green river
and the line of the Louisville, Paducah and Southwestern Rail-

                    SURFACE FEATURES.
  This region, for one in which the vertical height of the hills
is comparatively so small, affords considerable variety in its
topographical features, which have been formed solely by ero-
sive agencies slowly acting upon sedimentary rocks of various
kinds, which are comparatively undisturbed, and lie nearly
  A great variety of forms of topography are presented, which
offer fine illustrations of the effect of the different rock forma-
tions of a country upon its surface features by the different
degrees with which the rocks resist erosion. Resistance to
erosion has been alone the determining agency in forming the
topography; it has not been appreciably affected by distor-
tions, upheavals, or faults in the strata; for, taking the region
as a whole, it is very little disturbed, and the rocks usually
retain their original position, lying horizontally or dipping
slightly to the west.
  There are, it is true, in portions of this region, in the lime-
stones and sandstones of the Chester Group, a large number



of small faults, some of which extend up into the overlying
coal measures; but they are usually of small vertical extent,
rarely measuring more than 50 feet, and they do not seem to
have exerted any appreciable effect upon the topography.
There are few prominent hills, but the general surface of
the country may be best considered as a plain of considerable
elevation, with the variations in height caused by the streams
cutting through in different ways. The highest elevations will
not exceed 490 feet above low water in Green river, at Browns-
ville, or 920 feet above tide water, estimating Green river at
Brownsville as 430 feet above sea level-a level obtained from
the best data at command, which, however, are imperfect.
The general level of the country, on the ridges and compar-
atively flat uplands at the heads of the streams, is from 300
to 400 feet above Green river; while the level of the valleys,
which in the lower part of this region are usually quite narrow,
is from 200 to 250 feet below the uplands.
The drainage is all into Green river, chiefly through its two
principal branches, Nolin river and Bear Creek, although there
are a number of small creeks flowing directly into Greenriver,
in the southern part of the region.
To the north, on the ridge which forms the divide between
the waters of Rough Creek and those of Nolin river and Bear
Creek, and along which the Louisville, Paducah and South-
western Railroad passes, the surface cff the country is level or
gently rolling. To the south,it is much more broken, showing
high table lands with the streams cut as deep gorges or canons,
with precipitous and often impassable banks, affording remark-
ably picturesque scenery.
The topography of the northern portion is due to the al-
ternate thin sandstones, limestones, and shales of the Ches-
ter Group, which, not offering great resistance to the erosive
agencies, are acted upon quite uniformly, giving us even and
gentle slopes, except where there is a limestone or sandstone
thicker than usual, when the streams cut narrow and gorge-
like but shallow valleys, leaving the general surface above the
streams still comparatively level and unbroken. On the south,




a series of heavy, coarse sandstones, culminating in the mas-
sive conglomerate, which is from ioo to i8o feet thick, are the
determining rocks, and give us a characteristic topography.
  Where the massive sandstone forms the tops of the hills,
and is underlaid by friable shales and shaly sandstones, we
have for the uplands a nearly level surface, streams narrow
and precipitous at the upper part, where each one heads in
the sandstone, and wider below, giving occasional valleys
which afford good-sized farms of nearly level land. This is
the character of the topography over a large portion of this
region-of nearly all of that north of Sycamore and Dismal
Creeks to the edge of the coal measures. Here a massive,
thick-bedded sandstone, ranging from 40 to 6o feet in thick.
ness, lies near the surface, and gives character to the topogra.
phy. All the streams head in it, or cut their way through it
near their heads, where it shows many exposures of its full
thickness, in precipitous cliffs.
  Further south, the conglomerate sandstone is of great thick-
ness, and the streams are cut in it and the underlying lime-
stone. The result is, that they are little more than narrow but
deep gorges for their entire length, with little or no tillable
land even near their mouths. The walls of these gorges are
often precipitous cliffs from 75 to 150 feet in height. The
country is so cut up by streams of this class, that travel is very
difficult or impossible, except by following the main ridges or
divides between the streams.
  Some of the most romantic and beautiful scenery of the
State is to be seen on the streams of this region. The well-
known Dismal Rock, on Nolin river, at the mouth of Dismal
Creek, is but one instance among many. Piney, Pigeon,
Bylew, and the other creeks in the heavy conglomerate, pre-
sent a series of wild and picturesque cliffs which have been
rarely seen by appreciative eyes, but are well worthy the
attention of the tourist.  Were they more accessible, the
region would doubtless become a well known and attractive
resort. As it is, some of the finest scenery is but a short ride





from Mammoth Cave, and can readily be visited from that
Nolin river, from Dismal Creek to its mouth, cuts its way
through the heavy conglomerate. Its valley, which above had
been at some places of considerable width, at once narrows, and
at many places is little wider than the bed of the stream; and
the banks are so steep that it is with difficulty one can make
his way along them. In this distance, at almost every turn,
abrupt, precipitous cliffs tower above the stream from 150 to
200 feet high, and some even higher. Among the best known
of these are Dismal Rock, at the mouth of Dismal Creek, on
the very edge of the thickest conglomerate, Bylew Rock and
Whistling Mountain, one on each side of the mouth of Bylew
Creek. A sketch of Dismal Rock is given by Dr. Owen in the
first volume, first series, Kentucky Geological Reports.
  To the east we have the topography determined by the
heavy, massive, and cavernous limestone called the St. Louis
limestone. It is of great thickness, homogeneous, stratified
in heavy beds, with few shaly and friable members. Into this
Green river is cut deep, with high precipitous banks, but the
tributary streams on the surface are generally few and short.
The drainage is chiefly underground through the labyrinthine
caverns and crevices with which the limestone is honey-combed.
The country is full of sink-holes, funnel-shaped depressions,
into which the water flows and disappears. There are many
valleys which have evidently been cut out by streams when the
level of Green river was much higher than at present. As
Green river cut deeper and deeper into the limestone, the
tributary streams, having perhaps reached a level where the
limestone was more subject to the action of water, left their
former beds and sought an exit underground, through the
seams and fissures which were gradually enlarged by the sol-
vent action of the water until they form the numerous caves
which are so characteristic of that region.
  These in their turn were abandoned for other channels, as
the river cut still deeper, and the most of them remain com-
paratively dry. The surface of the country thus underdrained,



is fairly pitted with the sink-holes, into which the water runs,
and from them gradually drains away through the limestone.
Often the sink-holes become filled with clay and earth so that
the water remains in them the whole year round. If at any
time it is desired to drain them, it is easily accomplished by
simply digging down through the clay till the limestone is
reached, when the water sinks away at once. By reason of
the great abundance of these sink-holes the topography is
quite complex and varied, but the chief characteristics have
been already stated; they are absence of long streams above
ground, and abundance of sink-holes through which under-
ground drainage is facilitated.
  We have represented in this region only the rocks of the
carboniferous system, in the following divisions:
Carboniferous.                           Coal measures.
Sub-carboniferous or Mountain Limestone  Chester Group.
                                        ISt. Louis Limestmo.
  The description of these different formations will be given,
beginning with the lowest of the region:

                  THE ST. LOUIS LIMESTONE.
  This is the limestone known in the first series Kentucky
Geological Reports as the cavernous member of the Sub-car-
boniferous Group. It is the limestone in which Mammoth
Cave and all the similar caverns of that region have been
formed. It is usually quite homogeneous in structure, very
heavy-bedded, not very fossiliferous, occasionally somewhat
earthy in appearance, and shows conchoidal fracture. The
cavernous nature of this region is due wholly to the charac-
ter of this limestone. It is so homogeneous and thick-bed-
ded that such gigantic excavations as Mammoth Cave can be
made in it without its crumbling or falling in, and thus filling
them up.
  The greatest thickness of this limestone which we have
exposed within the field under discussion is about 230 feet,
which is its height above Green river at Mammoth Cave.




  In only a small portion of the field, covered by the accom-
panying map by Mr. Page, and that on the eastern part, does
this limestone come to the surface not covered by other rocks.
  The total thickness of this limestone in Kentucky has not
been accurately determined. It is, however, much thicker than
any exposure in this region, as has been proved by borings
made in search of oil some years since. One of these wells,
sunk on a branch of Dismal Creek, penetrated to a total depth
of 804 feet, of which the last 524 feet is said to have been in
solid limestone, and the boring was stopped without reaching
the base of it. This gives us a greater thickness of this lime-
stone below the drainage than we have exposed above. It is
true that all of this limestone may not belong to the St. Louis
Group; the limestone of the lower portion of the well may
be a still lower member of the sub-carboniferous system, such
as occur in other States, known as the Keokuk or Burlington
limestone; but until they have been recognized in this State,
it will be accurate enough to consider the whole thickness
as belonging to the St. Louis.
                    THE CHESTER GROUP.
  Between the massive St. Louis limestone and the sand-
stones and shales of the coal measures, there is a series of
irregularly and frequently alternated limestones, sandstones,
and shales, which mark a period of comparatively rapid and
frequent geological changes; a progress toward the conditions
which attended the formation of the coal measures, met by fre-
quent returns to those which enable the deposition of a fine-
grained crinoidal limestone, such as must have prevailed during
the long period of the deposition of the St. Louis limestone.
  From paleontological evidence, Mr. C. J. Norwood, Assist-
ant in the Kentucky Survey, has identified this series with the
Chester Group of the Illinois geologists. For the evidence
upon which the identification is based, see his report.
These rocks immediately underlie the conglomerate at the base
of the coal measures, and are exposed in nearly all this region.
  Nolin river has its bed in these rocks for the whole distance
covered by this report. Bear Creek runs in them from its head



to some distance below the mouth of Sycamore Creek. Rock
Creek likewise cuts its channel in them from head to mouth.
All of the branches of Nolin river, of any size, in the region
covered by Mr. Page's accompanying map, have their chan-
nels cut in the Chester rocks for the greater portion of their
distances. They usually head in one of the sandstones of the
coal measures; but the descent is rapid and steep until the
Chester limestone is reached, when it becomes much more
gentle and regular, and the fall is comparatively slight. The
same is true of all the branches of Bear Creek, except Beaver
Dam and Gulf Creeks, which, although touching the limestone
once in the course of their descent, run in the conglomerate
sandstone most of the way, as after these streams have once
cut through to the limestone, a rapid dip to the west again
carries it underground, and brings the conglomerate down to
the bed of the creek once more.
  The ridge forming the divide between the waters of Rough
Creek and Nolin river and Bear Creek, and along which the
Louisville, Paducah and Southwestern Railroad runs, is formed
by Chester rocks, which here extend southward three or four
miles before they are overlaid by coal measures.
  The total thickness of the rocks of this group, as shown
along the line of the Louisville, Paducah and Southwestern
Railroad, is given by Mr. Norwood in his report as 262 feet.
Mr. Norwood's general section of the Chester rocks, along
the line of the railroad, as given in his report, is sufficiently
accurate in its details for the northern part of the region cov-
ered by this report, but as we go south there is -a marked
change.  The great thickness of marly shales, called the
Leitchfield marls, and the numerous thin limestones, give place
to heavy-bedded limestones and sandstones. This change
svill be alluded to more in detail hereafter. The thickness of
the series, in the region covered by this report, does not vary
much from that given by Mr. Norwood. It may be stated in
round numbers at 250 feet.
  The base of the Chester series, the equivalent of the Big
Clifty sandstone of Mr. Norwood's report, is reached at but





few places, except on the very eastern portion of the field, on
Green river and its immediate branches.
  Some wells, which have been already referred to, sunk in
search of oil in this region a number of years since, pene-
trated through the entire thickness of this series and deep into
the underlying St. Louis limestone. The records of some of
these borings have fortunately been obtained for publication.
One of these wells was sunk on a branch of Dismal Creek by
Wm. C. Dodge, of Bowling Green, to whom we are indebted
for the records. This well was started just below the level of
the lowest coal of the neighborhood, and close to the top of
the conglomerate, which is here only 25 feet thick.
  The following is the record:

                      No.                            Thick- Total.
                              No.                     ness. depth.

Oeb.&-            J     ( lay.....     ..........      8    8
           .        &boxferos 33   2 Black sandstone (conglomerate S. S.)  25  33
                       3 Shale.....     ...... .. . .  25    58
                       4 limestone... .. .. .. . .. .   9    67
                       S Shale.     ...... . .. .         15    82
                       6 Limestone.... . .. .. .. . .  34   116
                       7 Shale.. .. .. . .. .. . .. .        124
Chestrseres; t thckne 239 t.  8 limestone ......  . . . . . . .  42  i66
                       9 '. Mud vein" (probably shale). . . . .  17 183
                       lo limeeton .      .20                203
                       t Black- sandstone. .15               218
                     112  , Sand and shale... .. . .. ..   42   26o
                       13 Shale... . S.           .o 280
9 L-6 fim-eot- 524 &e .1 4  .....et . 14  Grey limestone (St. Louis limestone) .  524  804

  The above record is given as it was furnished for publica-
tion. The names in parentheses are added by the author of
this report.
  The horizon at which this well was begun is well ascertained
to be the top of the conglomerate.
  We have shown by the above section 239 feet of Chester-
rocks, reckoning the shale between the conglomerate and
limestone, as belonging to this group. There is always a large
margin to be allowed for error in measurements, and for mis-
takes in recognizing the material through which the drill is
penetrating, as well as the precise point of change from one
rock stratum to another, in considering sections obtained by




drilling. It is a difficult matter, without the most careful
study, to tell exactly what is the material being penetrated by
the drill, for the reason that it is usually all finely pulverized,
and there is a considerable admixture of material broken down
from the sides of the well above by the drill-rods. Neverthe-
less, when these allowances are made, these records are of
great value, and should always be kept. In the case of this
well,there may be some errors in the record of the frequently
changing strata of the Chester Group, but it is not probable
there is any error in the total thickness, or in the measure-
ment of the St. Louis limestone.
  Other wells were sunk in this region on Rock Creek and
on Brier Creek; but as yet we have been unable to obtain the
records. Six wells, in all,were sunk in this region during the
oil excitement. The following is the record of one of these
sunk by the Kentucky Oil Company, on the Nolin Furnace
tract, near Bear Creek, above the mouth of Decker Branch.
The records were kindly furnished for publication by Col.
Chas. E. Smith, of Indianapolis, under whose direction the
well was sunk. The records were very carefully kept in de-
tail, but in the following account they have been somewhat
condensed and summarized. The exact geological level of
the mouth of the well is not known, but it is evidently not far
from the top of the Chester:

                                              Thickness. Total depth.
                                             Feet. Incbes. Feet. Inches

  XEarth         .                      . ...... .. . .. .. .             29.
  2 Alternate bands of shale and limestone, mostly limestone .   6  21   6
  3 Shale, with thin bands of limestone, mostly shale . . .  14  7  31
  4 Hard limestone..... .. .. .. . .. . ....    38    6    74  7
  5 Sandstone.... .. . .. .. . .. .. . .. ..   20    3   94    10
  6 Limestone....      ........                46    2   141 .
  7 Blacksandstone.......  .....................9 . . .  i50   
  8  "Mud" (probably soft clay shale) . ............. 6  . . . .56  .
  9 "Slate" (probably hard shale)... .. .. . .. ..    2    6   58  6
  so Fi ne-grained sandstone .....................9  . i9  6  178  .
  xx Black mud" (probably soft black shale) . -.-.-.-.-.- .  20  . 198 .
  - 2 Black sandstone.................              6 . .. 2o4
  13 "Slate rock".                               o.............  ......lo.. .  . .1214   
  14 Hard limestone (St. Louis limestone) . . -.-.-.-.-.-.- . 288 . . . 492 . . -





  By the above record, which is, of course, subject to the
before-mentioned liabilities of error, we have a thickness of
214 feet of Chester rocks, and 288 of St. Louis. We note
here the beginning of the change in the upper part of the
Chester to frequent thin limestones and shales, which are so
characteristic of this formation further north.
The heavy sandstone, which is the base of the Chester
series in the eastern part of this region, seems, as we go west,
to disappear and give place to alternate thin sandstones and
shales, the shales prevailing. This feature is shown quite con-
clusively by the two borings given above. Mr. Norwood also
reports finding the same character to this rock in the western
part of the coal field.
  Further north and east, the sandstone occupies its proper
place, growing thicker toward the east. Where the Louisville,
Paducah and Southwestern Railroad crosses Big Clifty Creek,
the thickness is stated by Mr. Norwood at 125 feet. At Mam-
moth Cave it is from 6o to 70 feet thick; but on descending
Green river to the west it rapidly decreases to 40 or 50 feet,
and even less. Near the head of Rock Creek it is 50 feet in
thickness, but lower down it is only from 25 to 30.
  In the region around Bee Spring, in Edmonson county, and
for some six to ten miles north, the character of the Chester
rocks differs materially from what it is in the neighborhood of
Grayson Springs and Leitchfield. In the Bee Spring region,
the series consists of three, and sometimes four limestones,
with shales and sandstones between, the sandstone prevailing.
The limestones, with the exception of the upper, are usually
massive and homogeneous, ranging from 15 to 45 feet in
thickness, and occasionally thicker. The upper is usually only
from two to ten feet in thickness, and is often in several thin
bands in shale. The section of the well last given shows this
feature very characteristically. This limestone is usually more
fossiliferous than the others. Where it is split up into several
thin bands, the aggregate thickness is usually greater than
when it consists of a single layer.




  The two wells, the records of which have just been given,
show typical sections of the Chester rocks of this region, as
just described.
  Further north, around Grayson Springs and Leitchfield, in
place of the heavy limestones at the upper part of this series,
we have a very changeable series of shales, marls, or marly
shales, thin shaly sandstones, and limestones. At Cedar Knob,
near Grayson Springs, a thickness of II 5 feet of these rocks is
seen, and the most of the shales and sandstones are calcare-
ous. The limestone here, which is persistent, is probably the
lowest one of the series. It occurs on Bear Creek, near Gray-
son Springs, and below. It is seen, at the Chapel, 40 feet in
thickness. It dips, however, rapidly down stream, and is over-
laid by the shales already referred to, which take the place, in
this region, of the heavy limestones further south. Above
Grayson Springs it rises rapidly.
  In the northern and eastern portions of this region the
Chester rocks are peculiarly subject to faults.  There are
almost innumerable small faults of from io to 50 feet vertical
distance. They are most abundant where the Chester rocks
are not overlaid by the coal measures, but in many places they
are seen reaching up through the conglomerate. They are
so numerous and irregular-not, so far as we can at present
see, following any general direction, any line of uplift or down-
throw-that they are often very perplexing, and render the
taking of accurate sections quite difficult. They are usually
local, and, in most cases, seem to be down-throws.
  The Grayson Springs issue near a fault of this kind which
extends through the lower sandstone and limestone of the
Chester Group. The line of this fault undoubtedly deter-
mines the position of these medicinal springs which are here
in so great number: the waters, from a depth, probably follow-
ing the line of the fault underground, as they find it the chan-
nel of easiest ascent. The number of springs here is great.
and their value high. For analyses of the waters from these
springs, see the report of Dr. Peter.




                DIP OF THE CHESTER ROCKS.
 The region covered by this report is really a projecting
 tongue of the coal measures in the form of a basin or trough,
 in which the rocks have a general dip to the west, while there
is also a modified dip from north and south toward the center
of the basin or trough. The Chester rocks underlying the
coal measures rise to the surface both to the north and south.
The northern edge of this basin is the ridge already referred
to, along which the Louisville, Paducah and Southwestern
Railroad runs. Chester rocks are the only ones exposed for
from two to three miles south, when they are overlaid by the
coal-measure rocks. They are seen, however, still dipping
south and west, on all the streams until Dismal Creek is
reached, when the dip begins to change and they gradually
rise toward the south, coming to the surface again on the south
side of Green river, beyond the field of the map. The rise
southward from Dismal Creek cannot be traced accurately in
many places, as the upper part of this series is cut away by
the heavy conglomerate. We only know that the rise does
take place, as we find the rocks much higher to the south,
even when the heavy conglomerate overlies them.
By reference to the accompanying cross-section, No. 2,
running nearly south from Grayson Springs Station to Green
river, the above mentioned facts in regard to the dip will be
readily seen. The lower limestone of the series is 30 feet be-
low the railroad at the station, which, by Mr. Page's levels, is
313 feet above low water in Green river, at Brownsville. The
rocks descend to the south by a series of small faults until we
find the top of the same limestone about 20 feet above Bear
Creek, at Grayson Springs, or 150 feet above Green river.
This descent is in two and one half miles distance. The top
of Cedar Knob, near Grayson Springs, is 330 feet above
Green river, with marly shales and limestones of the Chester
Group extending to the very top. The descent is quite rapid
from this point at first, something near go feet per mile, and
then more gentle, until at the crossing of one of the branches
of Dismal Creek, near Berry's Lick, where the upper Chester




rocks reach the lowest point on this section, i io feet above
Green river. The top of a limestone is seen lower than this
on Pigeon Creek; but this is where the upper members are
missing, having probably been cut away at the time of the
deposition of the heavy conglomerate. Near Brownsville we
have the highest Chester limestone exposed, i6o feet above
Green river. As already stated, the faults seem most abund-
ant on the northern and eastern borders of the region under
discussion. In the central region, between Nolin and Bear
Creek, faults seem  to be very rare.  Irregularities in the
upper surface of these rocks are, however, very great, espe-
cially where the heavy conglomerate rests upon it. These
irregularities are well shown along Green river, above and
below the mouth of Bear Creek. One half mile above the
mouth of that creek the limestone extends 50 feet above the
level of the river. At Bear Creek the conglomerate is seen
in the river banks, and the limestone near the level of low
water. Below Bear Creek, Mr. J. R. Procter reports the lime-
stone at Indian Fort as seen, 40 feet above Green river, while
one fourth mile below,it disappears below the drainage; the
top of the conglomerate at the same time descending from
235 feet to 125 feet above the river, thus showing undula-
tions equal to or greater than those in the limestone.
  In the northern part of this region there are numerous beds
of marly shale, which are quite conspicuous, in their frequent
outcrop,on account of their bright colors. They range from a
dark red to bright yellowish-green. As yet, they have been
only occasionally used, in small quantities, for paints. The
colors which can be obtained by the use of these earths are
fine, and they are capable of yielding an indefinitely large
supply. Analyses of these marly shales, from a number of
places, by Dr. Peter and Mr. Talbutt, give between four and
five per cent. of potash. They would, therefore, if the potash
can be rendered soluble, be of the greatest value as fertilizers,
especially for exhausted tobacco lands.  For the complete
analyses, and further information in regard to the value of
this material, see the report of Dr. Peter.



                    THE CHESTER COAL.
 At many points near the edge of this region, on Rock
 Creek, on Nolin river and some of its branches, as high as
 Roundstone Creek, on Dog Creek and Cub Run, and on
 Green river, there is found in the rocks of the Chester series
a thin coal. This coal has been already referred to in the
report of S. S. Lyon, fourth volume, first series Kentucky
Geological Reports, as having been found at the head of
Rock Creek. It has been observed at so many points that it
may be considered as of more than local occurrence. In fact,
it seems to be one of the best marked and most trustworthy
members of the series. It occurs at the base of a heavy lime-
stone, which is probably the lowest of the series. It has not
been seen by the writer of a greater thickness than three
inches, hence it is of no economical importance, as it is not of
workable thickness. It has served to delude some persons, in
times past, into the belief that they might find coal in quantity
to pay for working in places where only the Chester rocks
occur; but not much labor has been wasted in the search. It
usually has from a few inches to two feet of shale between it
and the limestone, and rests upon a thin band of fire-clay.
The coal is usually quite pyritous and somewhat slaty. The
overlying shale is pyritous also, containing casts of stigmariae
in pyrites. The shale contains abundant impressions of vari-
ous coal-measure plants, the leaves or spines of Lepidodendron,
Sf/henophyuzlm cordiates, &c. It usually immediately overlies
a thin shaly sandstone or marly shale, but is not far from the
top of the Big Clifty sandstone. The following section, at
Mr. Wise's, on the south bank of Green river, near Browns-
ville, shows the usual association of the coal:
Limestone, probably 35 feet in all, seen only.......... ..   .  25  feet.
Sandstone (partly covered) .40
Limestone.3. . ............ .... .3
Fire-cladyshl...... . . . .. .. . . . .. .. .                inch.