xt7hhm52g752 https://exploreuk.uky.edu/dips/xt7hhm52g752/data/mets.xml Lesquereux, Leo, 1806-1889. 1857  books b96-11-34700490 English A.G. Hodges, public printer, : [Frankfurt, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Paleobotany Carboniferous. Paleobotany Kentucky. Coal Kentucky. Pal5ontological report of the fossil flora of the coal measures of the western Kentucky coal field  / by Leo Lesquereux. text Pal5ontological report of the fossil flora of the coal measures of the western Kentucky coal field  / by Leo Lesquereux. 1857 2002 true xt7hhm52g752 section xt7hhm52g752 











PALAONTOLOGICAL



REPORT



               OF THE


FOSSIL FLORA OF THE COAL MEASURES


               OF THE


   WESTERN KENTUCKY COAL FIELD:


                BY



IlEo LESQVYER'E-ux,



PALZONTOLOGIST.

 This page in the original text is blank.

 



               INTRODUCTORY LETTER.


  DEAR SIR: I herewith submit my report on the identification of the
veins of the Southwestern Coal Measures of Kentucky.
  Permit me first to most gratefully acknowledge the liberal and en-
lighteded support that I received from you, to ensure the success of
my researches. It is by following exactly your directions, that with
the co-operation of Mr. E. T. Cox, your able assistant, we are able to point
out now, for the first time, some general and reliable characters, which
may prove of practical advantage for the identification of the richest
beds of coal of Kentucky, and of the whole coal-fields of the United
States.
  It was understood that I should only have to collect and examine
the fossil plants bf the Western Coal Fields of Kentucky, with essen-
tial references to the peculiar species of each bed of coal. You want-
ed thus to ascertain the practicability of establishing the order of su-
perposition, and by this means, the identification of the beds. I had
been engaged during two years, in following the same researches for the
state survey of Pennsylvania, in the anthracite coal-fields of that state,
and had obtained some interesting and practical results from the study
of the fossil plants found in connection with the shales of each bed of
coal. But as soon as we began our explorations, in the bituminous
coal-fields of Kentucky, it became evident that the marine element
was predominant in the shales of most of the beds, and that it would
be of little advantage to limit our researches to the fossil botany
only, since shells and remains of fishes were mostly found in the
shales, without any plants whatever. For that reason, and confident
that the general principles exposed hereafter, would prove reliable for
the distribution of the shells, as well as of plants, I determined to
carefully examine the marine remains of each bed, and to collect them
for comparison and study.
  Mr. E. T. Cox, who is entitled to his share of the practical results of
our explorations, being better acquainted with the shells than I am,
took especial care of this part of our work, and by his unremitting
reearches, and arduous labor, we have been able to collect a large num-

 



502       PALSONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.

ber of specimens, which have been subjected to your examination.
From them it is evident that the distribution of the species of shells
in the shales of a bed of coal is as reliable, for its identification, as
the distribution of the species of fossil plants.
  The following introductory remarks may appear out of place in a
local report like this, but I think that they are not without a practical
advanlage. They will give not only an answer to a question scarcely
understood as yet, and often put to us by persons interested in the
coal business, viz: what is the coal, and how has this fuel been formed
But they will also enable the reader fully to understand the practical
deductions, and to test their value.
   It is unnecessary to dwell on the advantages of undoubtedly ascer-
taining the geological level of a bed of coal, since it is evident that
profitable explorations for coal can be made, with some chances of
success, only from the directions of a previously ascertained and well
established geological level. When this is exactly ascertained, a sin-
gle glance at a vertical section of the measures gives an answer to the
question: at what distance above or below shall we expect to find
another coal, and what will possibly be the thickness of the bed
   The few quotations and references to researches previously made by
myself, in the coal-fields of Pennsylvania and Ohio, will be easily
excused, since they tend to solve the problem of the coeval formation,
even of the primitive connection of all the coal-fields of the United
States-a question most interesting for geology, and eagerly discuss-
ed just now. And as for the right I may have to quote a few lines of
a report delivered in 1854, to the director of the Geological State Sur-
vey of Pennsylvania, and of which a small pamphlet, " Description of
new species of fossil plants, ke.," has only been published, I do not
think that it can be denied me. This report, elaborated with great
care, and the arduous labor of two years, was to appear in the final
report of the Geological State Survey of Pennsylvania, but it is a
question if it will ever be published. Therefore, I do not think that
I am bound to entirely disregard some scientific results, which may be
of general advantage, for the only reason that they have been made
under the direction of another state.
             I am, sir, most respectfully, yours,
                                           LEO LESQUEREUX.
 Dr. D. D. Owzi, Diredor of Me &OB Hunrey of Kenauokt

 



              INTRODUCTORY REMARKS.


  In tracing the features, and studying the rocks and compounds of
the earth's surface, no problem has more frequently occupied the mind
of geologists than the formation of coal. Where does this black sub-
stance come from, bard as stone, and nevertheless inflamable as wood;
half bitumen, half charcoal, encased between beds of shale and rock,
which, by their fossil remains, their fishes, shells, or plants, attest the
highest antiquity  Has coal been originated in the bowels of the
earth by some volcanic agency, and deposited in a fluid state, like the
lavas or the primitive rocks of many mountains  No! for it is strat-
ified, laminated, extended in horizontal beds, covering very large sur-
faces with a nearly constant thickness. Moreover, the shales in which
it is ordinarily incased bear evident proofs that they have been slowly
deposited in a quiet water basin, and that subterranean fire has had no
action upon them, except perhaps as a hardening agency. Or, perhaps,
has coal been made of the remains of extensive forests, overthrown,
transported, and deposited again in valleys and hollows, by an uni-
versal flood. But, by such a cataclysm, those remains could not have
been distributed in an harmonious manner, in extensive beds of equal
thickness, and especially in such purity that they scarcely contain any
particle of mud, saud, or any substance that does not belong to the
chemical compounds of the wood. For the same reason, also, the beds
of coal cannot be the result of heaps of drift-wood along the banks of
the large rivers, or on the shores of the sea. It is then necessary to
admit, with most of the best living geologists, that the coal beds have
been formed nearly in the Eame manner as the peat-bogs of our own
time, and that the coal itself is nothing else but decomposed and har-
dened woody matter, remains of immense and successive forests, grown,
decayed, heaped up, and then entombed on the spot, in their gigantic
shrouds of black slate, of black, white, and grey limestones, or of yel-
low sandstone.
  But such an explanation is too general, too indefinite, to be easily un-
derstood, and especially to give a satisfactory account of the various

 



PALEONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



accidents which have accompanied the formation of the coal. And
since it is, from the nature of the shales of the coal-beds, and from the
remains, whether plants or animals, found in connection with them, that
the writer of this report intends taking the characters that may help to
'heir identification, or to the ascertaining of their geological level, it
is necessary to give, at least, the details that may be justly required,
as reliable proofs of the validity of his opinion.
  The vegetable is cotemporary with the animal kingdom. Plants
and animals have appeared at the same time on the earth, and grown to-
gether in parallel lines-for the remains of marine plants or fucoides
are found in the oldest stratified rocks, in connection with the petrified
remains of shells. As soon as a part of the earth's surface has been
thrown out of the sea, like a new-born child, nature, its kind mother,
has covered it with the green carpet of another vegetation. But the
rise of a solid surface above the sea does not appear to have been a sud-
den and paroxismal event. Impelled by the action of an internal fire,
the crust of the earth, still thin and scarcely solid, was continually
swelling here and there, with a variety of undulating movements-
ascending and then subsiding at the same place-either propelled by
the internal fire, or depressed by its own weight, when the force lost its
energy. In this manner, ranges of hills began to appear, breaking
the monotonous horizon of an universal ocean; and at their base, im-
mense plains, leveled by the long protracted action of the waves, being
by and by raised to the surface and separated from the sea by heavy
banks of sand, were thus transformed into shallow marshes, prepared
for another kind of vegetation. Such marshes though. of a far more lim-
ited extent, are seen in our time along the shores, both of the Atlan-
tic and of our great lakes, the Dismal and Alligator swamps of the
south; the Sandusky, Montezuma, and Toledo marshes of the north.
   But before those immense plains were thus slowly elevated and sep-.
arated from the vast deep, the sea came for a long time, breaking its
waves against the primitive hills, or at least, was long engaged in de-
posi'ing around their base the mud with which its waters were charged.
Those gigantic deposits of red sandstone, bordering the coal basin on
its eastern margins, are especially the work of the tides. Like the
conglomerates which were afterwards deposited upon them, they thick-
en to the east, and nearly disappear in the contrary direction, evidently



504

 



PU-AONTOLOOICAL REPORT OF GEOLOGICAL SURVEY.



showing where then were the first shores of the ocean-the first out-
line of the Alleghany mountains perhaps.
   The conglomerates of the anthracite basins of Pennsylvania are
about fifteen hundred feet high, composed of sand and pebbles of
quartz, which are sometimes as large as hens' eggs. On the contraryi
in the western part of the Coal MNeasures, in Indiana, Kentucky, and
Tennessee, they are comparatively thin, and of a finer texture-just as
it happens that near the shallow shores of our lakes, or of the Atlantic,
the gravel and coarse materials of the bottom are heaped by the waves
nearer to the margin, in proportion to their size, the finest particles of
sand being necessarily drawn farther from the shores where the action
of the waves is less violent. It was in this manner that the first basin
of the coal was prepared. Bordered to the east by a chain of hills, the
bottom was slowly upheaved, and the ocean damed far away to the
west, began there, by its perpetual movements, to build again its new
shores, and to close in the coal basin with high banks of sand and grav-
el. This separation was necessary, for a shallow, quiet, water, of a
constant level, is the first condition of the formation of peat, and con-
sequently of coal.
  The plants of the bogs have a peculiar growth and a peculiar com-
position. They live ordinarily half immersed in water, and raise their
stems, branches, leaves, and flowers above the surface. They are gen-
erally of a woody texture. Even the mosses and the grasses of a
peat-bog contain, comparatively to their size, as much woody fibre as
the hardest oak. The trees are most of them resinous. In the north-
ern part of the United States the balsam-fir, the black and white
spruce, the tamarck, the arbor-vitae and the white cedar; in the south,
the bald cypress, the great and Emall laurel magnolias, the tulip-tree,
are commonly seen growing on the cedar swamps, with birches, alders,
poplars, and other resinous shrubs. The peat bogs of Europe are
abundantly covered with a kind of dwarf-pine, from the leaves and
twigs of which the rosin trickles upon the mossy ground, forming all
around the trees a hard floor of tar many inches in thickness Most
of the plants of those marshes, vxcept a few trees, belong to that pe-
culiar station; they do not grow out of their bogs, neither can they
be transported and cultivated out of them. For that reason the vege-
tation of the cedar swamps cannot be taken as a true representative of

             64



506

 



5ALRONToLOGICAL REPORT OF GEOLOGICAL BURVEY.



the fipra of a whole country. It has its place in the harmony of na-
ture, like the fruits and flowers of our gardens, the grass of the prairie,
the trees of the forest. It was destined for the condensation, the pre-
servation of carbon, for the formation of coal. For truly, when we
examine fossil plants that have been preserved in the shales of the
coal, or when we analyze the substance of the coal itself, we find that
the plants which formed it have the greatest likeness to those of our
actual peat-bogs, viz: the ferns, the club-mosses, the horse-tails, the
rushes, the reeds, and especially the resinous trees. The most remarka-
ble difference is that all these plants, compared with those of our time,
were of a monstrous size. They were, indeed, the mastodons, the
mammoths, of the vegetable world.
  Every body is now acquainted with Liebig's explanation of the corn-
bustion and decomposition of wood. When heat is applied to it, it
burns with flame, developing carburetted hydrogen. When woody
fibre is brought into contact with air, in a moist condition, it is gradual-
ly decayed, viz: changed into mould or humus, by the conversion of
the oxygen of the air into the same volume of carbonic acid. Its
carbon is then not only preserved, but augmented. When the access
of air is restrained, decay, or a slow burning of the wood, is in like
manner produced, but the process is different  The disengagement of
carbonic acid, though continuous, is slight, and the final result is
charcoal, wood-coal, lignite, mineral-coal, anthracite, even diamond,
according to the conditions under which this slow burning has taken
place  the quantity of water, the more or less free access of the oxy-
gen of the air, compression, heat, &c. Says Liebig: "A slow bat con-
tinual removal of oxygen in the formr of carbonic acid, from layers of
wood-coal, or of wood immersed and decomposing in water, transforms
necessarily the woody substance into mineral coal. On the contrary,
the removal of all the hydrogen of mineral coal, converts it into an-
thracite." From this we draw the conclusion, that for the formation
of coal, a large production of woody fibre, at a constant water level, is a
necessary condition.
  The presence of the water, and its constant level, are necessary not
only to prevent a too rapid decomposition of the wood, but also for the
vegetation, itself, of the marshes. Plants living entirely immersed in
water, do not have a larger proportion of woody fibre in their tissues.



506

 



PAL.ONIOLOGICAL REPORT OF GEOLOGICAL SURVEY.



The fucoides, or marine weeds, are of this kind. To elaborate wood,
the plant wants the contact of the air with the porous surface of its
leaves. The marsh plants, then, having their roots fixed in the ground
below water, expand their leaves either on the surface of the water or
above it.  Trees need, for their vegetation, the absorption of air
through their roots. Hence, those which grow on the bogs, extend
their roots and rootlets in a large circuit, let them run near the surfhace
among the mosses, and ordinarily plant themselves on a higher level,
either on the decayed trunks of other trees, or orn some heap of mat-
ter. In any case, a formation of peat is impossible in a marine basin
not entirely secured against the action of the tides, or in the marshes
of rivers, which, though covered with high water in the spring, become
dried by the heat of the summer months. Along the shores of the
ocean, of our lakes or our large rivers, there are extensive marshes,
inaccessible during the spring, and even during part of the summer,
covered with rushes and reeds, the bottom of which is constantly and
slowly elevated by thin layers of mud or clay, but never covered with
peat.
  The same phenomenon is produced in lakes and bayous, where water
is too high for the growth of the plants, and on the borders of which
the water level is not constant. The matter deposited at the bottom
of those deep marshes is constantly a fine mud.
  There is perhaps no place in the world where the process of the for-
mation of coal may be studied, with better chances of a clear elucida-
tion of all its phenomena, than in the Dismal and Alligator swamps
of southern Virginia and North Carolina. The extent, though truly
nothing compared with the area of the coal-fields of America, covers
nevertheless, thousands of square miles. They are separated from the
bays and sounds that surrounds them by broad hills, and large banks
of sand, bordering the Atlantic, in a continuous row, from Cape
Henry, or Norfolk in Virginia, to the mouth of Cape Fear river, or
Wilmington in North Carolina. They contain, in their wide area, sand
hills, deep deposits of peat, and lakes. The hills are covered with the
vegetation of dry land. The peat, from one to fifteen feet thick,
follows at its bottom the irregularities of the surface on which it rests,
thinning and disappearing entirely where it abuts against the hills:
for a bed of peat, depending for its formation on the level of the water,



607

 



508        PALRONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.

has just the same apparance, or at least, by a cross-section, would
present the Eame front as the transverse soundings of a shallow sheet
of water.




                                             C
 Fro. 1. Appro-iwe sectkon across the Dis-al Swampa Deposits of peat. a' Depo-
 sits of trees at the bottom of Dummo.d's lake. 6. Surface of lake Drummond. c. White
 clay of the bottom- d. Hills of sand. e. Sand below the marsbes.

 As for the vegetation itself, and its action on the formation of the
 peat, let any tourist try to find his way directly across the swamp, from
 some point on the canal to Drummond's lake and he will understand
 at once all about the mystery of the heaping of vegetable matter.
 Wading at least knee deep in water, or in a black soft mud, or sinking
 at every step deeper and deeper in the hillocks of green mosses, where
 he thought to find a dry and solid footing for a minute's rest. he has
 literally to cut a path through a wall of canes, of reeds, and of shrubs.
 The only place where he finds firm stepping and a clear space, is on
 the roots of the bald cypress, which raise themselves above the water
 around each tree, like the scalped skulls of a tribe of Indians; or,
 perhaps, on the prostrated trunk of a huge magnolia tree, covered with
 mosses, and slowly sinking in its muddy grave, not to decay, but to be
 embalmed and preserved like an Egyptian mummy. Every year the
 mingled mass of vegetation, the mosses, the canes, the reeds, the
 trunks, branches and leaves of the trees and shrubs, are heaped and
 deposited on the surface of the bog, to be, by and by, transformed into
 combustible matter, by the process of slow decomposition.
   Some of the lakes now open on the surface of the marshes have cer-
tainly been hidden, formerly, by a thick coat of vegetation. Drum-
mond's lake is only fifteen feet deep, and its bottom is strewn with
the remains of an overthrown forest, which has probably sunk by its
own weight. Phenomena like this are frequent in the large peat-bogs
of northern Europe, especially in Sweden, Denmark       even in the
mountains of Switzerland. The green carpet of vegetation which, by

  Tbe figure is drawn without reference to any exact proportions in depth it represents
about one foot In the t pact of an inch; In Iserb o9e inch would represent maore than two
miles

 



PALMONTOLOGICAL REPORT OF GEOLOGICAL EURVEY.



the agency of floating mosses, spreads on such lakes, is sometimes so
thin that it breaks under a light pressure, and men and animals are
frequently engulfed and irretrievably lost in their treacherous waters.
The rich cabinets of Lund and Copenhagen are filled with antiquities
collected in the peat-bogs of that country-weapons and armor;
ornaments of copper, silver and gold; tools and instruments of every
description; bones and skulls of extinct or living races of animals; of
men also; even the whole skeleton of a woman, with her clothes, have
been found imbedded in the peat.
  Drummond's lake has now been open for many hundred years; its
black water has entombed its sunken forest under a bed of mud. The
surface of the lake, like the general surface of the Dismal swamp, is
only 16- feet above mid-tide of the Atlantic.  If we suppose a slow
depression of all the space covered by the Alligator and Dismal swamps,
of say only a few feet in a hundred years, what would be the result
At first the water rises above its former level, since its outlets are ne-
cessarily obstructed, and the remains of the plants still growing here
and there upon the hillocks of the marsh, fall every year into the wa-
ter and sink to the bottom-not to add any more matter to the bed of
the peat, but to be incorporated with the soft mud continually deposi-
ted by the water. If the downward movement continues, every trace
of vegetation must disappear, and the marsh forms an extensive lake,
connected by some outlet with the sea, which brings to it a few species
of its inhabitants, either fishes or molluscs; and, by and by, after a
still lower depression, either the sea spreads quietly over the whole
space, and its water covers it with a deposit of limestone, wherein are
imbedded the remains of the shells and animals of the deep; or, per-
haps, after a sudden cataclysm, there is a depression of a few feet, and
the sea, overcoming its barriers, rushes into its old level, sweeps over
its old bed with impetuosity, and brings with its waves the banks of
sand and the gravel of its shores, to scatter them more or less irregularly
over the whole surface. Let the land rise and the water recede again,
and the formation may be repeated many times, with many modifica.
tions. This simple work of nature, operating in this wise for an im-
mense number of ceuturies, will necessarily result in the transforma-
tion of the whole Stratum to true Coal Measures. The compressed
and crystallized peat will be the coal; the soft mud slowly deposited



509

 



PALZONTOLOGICAL REPORT OP GEOLOGICAL SURVEY.



upcn it by quiet and shallow waters, will be hardened to black shales,
and show us the petrified remains of plants, shells, or fishes. The de-
posits of the deep, quiet, marine waters, have formed a bed of lime-
stone above it, and if, afterwards, sand has been brought in by the cur-
rents of the sea, the whole mcasures-coal, shales and limestone
become covered with sandstone.
  The only thing not explained above, is the formation of the fire-clay
of the bottom, which, by a cross-section, would certainly be found un-
der the coal of the Dismal Swamp, as it is found under nearly every
bed of the old Coal Measures.
  As we have seen before, the woody matter deposited in a basin can
only be preserved and transformed, if the water is of a constant level.
Resting on the sand, the water percolates through it, and consequently
is subject, by a constant motion, to a perpetual change of chemical con-
stituents, and to a renewal of the particles of air which it contains.
This change is opposed to the formation of peat, since water, before
being prepared for the preservation and transformation of woody sub-
stance, has to become saturated with a peculiar acid-the ulmic acid-
produced by the decomposition of wood itself.  Thence it follows, that
a peat or coal basin has to be separated and prepared to keep its water,
like a well cemented cistern. This work is done by very small animals
-iufusoria-and by peculiar species of plants.  In the peat forma-
tions of the present day the clay bottom of the bogs is prepared by
fresh water molluscs and infusoria, and by the vegetation of the char-
ace(e and confervce, two families of cryptogamous plants, which disap-
pear entirely, as soon as the peaty vegetation begins. They fix in their
shells, or in their tissue, the carbonate of lime or the silica,
abundantly dissolved in some water, and by their decomposition they
deposit those substances at the bottom of the water in the form of a
very fine mud. In Denmark, there are some perfectly isolated ponds,
vhere this soft mud or clay is formed, by the agency of the above
named animals and plants, at the rate of one foot and more in every
five years.
  As there is no bed of peat, but is underlaid by soft white clay, so
there is no bed of mineral coal without its bottom of fire-clay, except
when it has been deprived of it by some accidental circumstance. This
fire-clay is free from remains of animals and shells, but it contains very
abundantly the stems and leaves of a species of plant, &tigariafmi-



610

 



PALAuNTOLOGICAL REPORT OF GEOLOGICAL BURTEY.



des, (plate 7, fig. 2,) which undoubtedly, like the Chara and the
iorsetail of our time, has especially contributed to fix the silica, and
to precipitate it to the bottom with its remains.
  In this abridged exposition we cannot discuss the value of any of
the above made assertions. Nevertheless, not one of them has been
admitted without a critical examination, and after its trnth has been
ascertained by serious researches, or by reliable authorities.
  The formation of the coal being thus understood in its whole, it is
easy to draw from it the explanation of the different modifications of
the Coal Measures, and to deduce some general rules for the identifica-
tion of the veins.
                         Is,. THE FIRE-CLAY.
  This clay, ordinarily full of rootlets and stems of stigmaria, so gen-
erally underlays every bed of coal, and its general appearance and
chemical elements are so much the same, that except, perhaps, for its
general thickness, it cannot become a very reliable guide for the iden-
tification of the beds. Even its thickness is variable.  It depends on
the depth of the basin in which it is formed, and on the regularity of its
bottom-thickening in the hollows, and sometimes entirely disappear-
ing near the margins of the basin. Variously tinctured by more or
less of oxide of iron, it is generally whitish, but sometimes as red as
ochre, and even variegated like marble, in the same bed. The quan-
tity of stignzaria found in it is as variable as its color, and as for its
chemical elements they depend, like the color, on the mixture of iron
and lime, especially silica and alumina, which are never uniformly dis-
tributed in a wide expanse of shallow water. This fire-clay of the Coal
Measures appears sometimes alone, and without any bed of coal above
it. In which case it may be intermixed with layers of shales, covered
with the remains of plants, especially of ferus. Then it indicates only
the place which was prepared for the vegetation of a bed of coal.
Some aocident-the shallowness of the water perhaps, or some dis-
turhanoe of its level-has prevented the growth and accumulation of
vegetable matter in sufficient abundance to form the coal. But the
plants, growing upon the marsh, have been imbedded and preserved in
the shales above the fire-clay as testimony to its natural destination.
Nevertheless, those isolated beds of fire-clay, overlaid by plants, are not
always barren of coal, and by following them to some distance the coal



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PALJEONTOLOGICAL REPORT OF GEOLOGICiL SURVEY.



is often found somewhere reposing on their surface. The fire-clay is
generally a reliable guide for the identification of veins, when it sepa-
rates two beds of coal, forming what is generally called a clay parting.
In this case, it is ordinarily found, though of variable thickness, over
a wi'de extent. But it is then formed like the shales; in some cases, it
is even a true shale, and it is in the examination of the shales that
the reason of its formation, and of its appearance, ought to be looked
for.

                            2nn. THE COAL.
   There is no substance of which so many chemical analyses have
been made, and none, also, of which the chemical elements are so well
known. The general result of all these analyses has proved a curious
fact, viz: that two pieces of coal, taken from the same bed, at only a
few feet distance, have scarcely ever presented exactly the same propor-
tions in the quantity of their essential compounds. The reason of this
is easily understood: each plant, especially each kind of tree, has for its
wood a peculiar composition; each one is more or less resinous, hard or
porous, has more or less of woody matter in an equal volume, and each
plant has a peculiar acid; all the essential elements are locally preserved
in the coal. The same remark is true of beds of peat, of which two slices
cut either horizontally or vertically, at a distance of one or two feet from
each other, never present exactly the same appearance, nor exhibit ex-
actly the same proportion in their chenmical elements. Some plants of the
coal-the C(Jlamites and the Sligmaria especially, fix in their tissue the
silica of the water, and the quantity of ash varies in proportion to their
abundance in the coal. Some others are porous, and when lying on the
surface of a bed of coal, they let particles of mud percolate through, or
within their tissue, and produce the same result in another way, and at
another place.  From these different causes, the ashes of the coal have a
different color, and the distinction of white ash and red ash coal, which
may be of great moment in the identification of the beds of part of a
basin, is, when considered in a general point of view, of little value. If
we may rely on the sections of the anthracite basins of Pennsylvania
as they are generally given, the upper beds of it belong to the red, the
intermediate ones to the grey, and the lower ones to the white ash se-
nies. In the coal-fields of western Kentucky and of Illinois, the
upper beds of coal are white ash, the middle ones red, and the lower



5a 12

 


PAL.XONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



grey or reddish-'  The classification of the colors could not be more
completely reversed.
   This color of the ashes is probably, also, in immediate connection
with the nature of the vegetation which has formed the coal. In the
peat formations the matter formed by the heaping and decomposition
of trees gives white ash; a compound of small herbaceous plants,
ferns, rushes, canes, mosses, gives red ash; and a mixture of both
forms the grey color of the ashes of some beds.
  The external appearance of the coal is as much varied as its chemi-
cal elements. The trees, sometimes, when they are very resinous,
have formed, by their decomposition, such a compact and homogeneous
mass, that the coal receives a peculiar appearance; it is then known
by the name of cannel coal. Another species of wood preserves,
even in the coal, some trace of its primitive texture, and shows, in its
fracture, a peculiar reflection of light, called, by the miners, the birds
eye.
  The coal is mostly stratified in thin laminme or coats, alternately
shining and dull-an appearance which clearly indicates an annual de-
posit of decayed vegetable matter, and the action of the water on it,
during the winter time, or before the beginning of a new vegetation.
The stratification of peat is exactly the same as that of coal; but the
layers are variable in thickness, from the sixth of an inch to one inch
and more, becoming natuarally thinner under a great compression, and
nearer to the bottom of the beds.
  The laminated appearance of coal is already a proof against the of-
ten repeated opinion, that it has been formed by the overthrow of vast
forests; but there is a more conclusive argument against it. One
acr