xt7wdb7vn46x https://exploreuk.uky.edu/dips/xt7wdb7vn46x/data/mets.xml Kentucky. State Geologist. 1882  books b97-20-37305401 English Stereotyped by 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 Lincoln County.Linney, W. M. (William M.) Report on the geology of Lincoln County  / by W.M. Linney. text Report on the geology of Lincoln County  / by W.M. Linney. 1882 2002 true xt7wdb7vn46x section xt7wdb7vn46x 











GEOLOGICAL SURVEY OF KENTUCKY.



JOHN R. PROCTER,



DIRECTOR.



                 REPORT


                    ON THS



GEOLOGY OF LINCOLN COUNTY.



BY W. M.



LINNEY.



STEREOTYPED FOR THE SURVEY BY MAJOR, JOHNSTON A BARRETT, YEOMAN PRESS, FRANKFORT, KY.

 This page in the original text is blank.

 















            INTRODUCTORY LETTER.



JOHN R. PROCTER, ESQ.,
              Director of the Kentucky Geological Survey:
 DEAR SIR: Please find accompanying this my Report on
 the Geology of Lincoln County.
 Thanking you for your unvarying kindness, and for repeated
 favors received from your hands,
                      I am, respectfully, yours,
                                    W. M. LINNEY.
 HARRODSBURG, Ky., December, i882.

 This page in the original text is blank.

 





GEOLOGY OF LINCOLN COUNTY.



                     TOPOGRAPHY, &C.
  Lincoln was one of the original counties created by the
Legislature of Virginia in 1780; and at that time comprised
ahont one third of the area of Kentucky. Since its first
organization, it has been shorn of most of its territory by
the formation of new counties, until now it comprises about
one hundred and ninety-five thousand acres. It is bounded
on the north by Boyle and Garrard, on the east by Garrard
and Rockcastle, on the south by Pulaski and Casey, and on
the west by Casey and Boyle counties.
  In i870 Lincoln county-had a population of ten thousand
nine hundred and forty-seven. This number had, in i88o,
increased to fifteen thousand and eighty. Stanford is the
county seat and the largest town, and in i88o it contained
twelve hundred and thirteen inhabitants, a gain of four hun-
dred and sixty-one in ten years. There are a number of
other small towns, among which are Crab Orchard, near Crab
Orchard Springs, well known as a summer resort, and Hus-
tonville, in the southwestern part of the county.
  The Cinlinnati, New Orleans and Texas Pacific Railway
(Cincinnati Southern) extends through the county in a direc-
tion northwest and southeast. The Knoxville Branch of the
1lotlisville and Nashville Railroad passes through in a more
directly east and west course. The Kentucky Central Rail-
road has connection with the latter at Richmond Junction, and
it is highly probable that it will be continued through the
county, and thence to Nashville, in the near future.
  A portion of the county is well supplied with turnpikes,
which are substantially constructed of broken limestone, or of
pebbles and gravel, which form beds in all of ithe streams.

 


GEOLOGY OF LINCOLN COUNTY.



Stanford has two good schools-one for males and the other.
for females. Hustonville and Crab Orchard have enjoyed fair
facilities for educating the young, while the popular schools
have been conducted with more than average success in the
county.
   There are no manufactories of any great extent. There
are several flour mills, three or four distilleries, and a number
of saw-mills, which ship a portion of their products. Grain,
live stock, and lumber are the principal exports, with a limited
exportation of Crab Orchard salts. The surface features of
this county are varied; in general terms, it may be said that
the northwestern half lies almost wholly within the commlionly
called Blue grass Region of the State, and includes surfaces
which are either level, gently undulating, or highly rolling.
These lands comprise the agricultural region of the county,
and contain many fine farms and much material wealth.
  Nearly the entire drainage of this part of the county is
into Dix river, which stream passes partly through and partly
along the eastern portion.  Hanging Fork rises iear the
Casey county line, flows northeasterly, and enters Dix river
near where Boyle, Garrard, and Lincoln counties come to-
gether. This part of the county has a perfect drainage illi
the great number of small creeks which unite with those
larger streams.
  On Dix river and Hanging Fork, near the mouth of the
latter, are some perpendicular cliffs, which rise something like
one hundred feet above the water. They are soon lost in
going up either stream. The general surface in this part of
the county does not rise high above the general drainage
linees; and in this feature they are in marked contrast with
the deep cations seen but a few miles down Dix river, between
Boyle and Garrard counties.
  The southern and part of the western boundary ot this
region is encircled. with a belt of isolated hills, usually termed
"knobs," which rise from one to two hundred feet above it.
These make a pretty and picturesque frame to the more level
lands.



6

 

GEOLOGY OF LINCOLN COUNTY.



  Beyond the knobs the elevation is somewhat higher, but
slopes gently from them for a long distance towards the south-
east. This part of the county is deeply cut by the drainage
lines which flow partly into the Cumberland and partly into
Green river.  Here the surface has not been so largely
cleared of its forests for agricultural purposes; consequently,
the streams are clearer, and their average flow greater througlh
the year, than in the more level fa-rming lands where the
Woods have been largely destroyed.
  From some of the greater elevations which mark the water-
slhed between the tributaries of the Cumberland and the Ken-
tuLcky rivers, there are extended landscape views which are
not excelled in beauty from any of the altitudes which stir-
round the far-famed Blue Grass Region. One of the finest
of these may be seen from a point above Hall's Gap.
  More than a semi-circle is opened from this point, and for
miles and miles one may trace the salient points to where the
fringe of forest and the horizon blend together. Spread out
to the -eye is more than half of Boyle, Lincoln, and Garrard
counties, with portions of several others. The dotted dwell-
ings, the open fields, the skirted woodlands, the sloping hills,
and the winding valleys, encompassed with a rim of highlands,
make a charming picture.
  A few miles to the south one may gain points from which
X iews may be had that reach far into Rockcastle, Pulaski,
and Casey counties. Here one sees a country of sparkling
streams and widespread forests stretching back to where hills
rise like mountains in the dim distance. It is worth the walk
of many sumnmer days to reach the numerous points in Lin-
coinl county from which nature has unrolled so many and such
varied scenes.

                 ANCIENT GEOLOGY.
  All the rocks which are exposed in Lincoln county belong
to the three great ages, the Silurian, the Devonian, and
the Carboniferous, which make the Paleozoic Time. Neither
the beginning nor the ending of ancient time is recorded in



7

 

GEOLOGY OF LINCOLN COUNTY.



the exposures here, nor do the beds have the great thickness
here which they attain at other places. They are, however,
not without interest, as in a few miles they may be traced
through many groups, and their changes noted in the rocks
and soils in the surface features and in the forests.
  The lowest rocks brought to view in the county are to
be seen near the mouth of Hanging Fork of Dix river, and
the highest near Highland Post-office. By tracing the out-
crops between these two points, a thickness of over fourteen
hundred feet is exhibited. Some of them are to be seen
only in limited localities, and they mark but a small feature
in a general way. Could these rocks all be seen together,



and in their geological positions, they would
the following divisions and measurements:



exhibit nearly



                                                  Feet.   Feet.


 Subearboniferous..... . . Upper      .375
                         Lower.30

 Hamilton.Black slate . . . . . . . . . . .        50      65
 Corniferous.            Corniferous limestones....   15 6
     ._U_ . _
  E5T  l urian
  Clinton ..... .. .. . . Crab Orchard shale......   40)     75
  Medina..     ......... .. Medina sandstone.  .....    35X

Lower Solurin-
Hudson River.... .. .. Upper beds.. .. .. .. .    300         0
                         Middle beds.              150  i  650
                         Lower beds.... .. .. .    200

 Trenton... .. .. . ..  Trenton limestones.17) 1
                         Birdseye limestones..... ..   90 f

    Total..... .. .. . . . .. .. .. .. .. .. .. . .. .   1,430



       LOWER SILURIAN-TRENTON EPOCH.
  Birdseye Group.-The rocks to be seen in Lincoln
county which belong to the Birdseye Limestones are exposed



8

 

GEOLOGY OF LINCOLN COUNTY.



9



for a few miles on the Hanging Fork and on Dix river, near
where those two streams come together. The) constitute
the heavy -walls of nearly vertical cliffs for about ninety feet
above the water. Those strata are the continuation of the
same beds which have been described in the Reports of Mer-
cer and Garrard Counties.  There is no change in theWt
general character, being heavy-bedded, mostly dove- colored
stones, fine-grained and brittle.
  They afford no characteristic soils here, and have only been
quarried to a small extent, and that for only local purposes,
though good quarries could be opened in them. There is a
sharp dip in the rocks here to the southeast, and the) are
soon carried beneath upper ones, and are seen no more in the
county.

  Trenton Limestones.-The limestones and shales of
the Trenton, which overlie the Birdseye group, are to be
seen in Lincoln county, exhibiting their usual phases; but,
like the beds which underlie them, they disappear beneath
the drainage from the same cause which carried the others
clown.
  lIhe ordinary features of the Blue Grass beds, the Granular
Limestones, and the Upper Birdseye beds, are to be seen
over a very limited surface. Eight or ten farms in the county
are situated in whole or in part over these beds. They are
all located near the Hanging Fork, and within a mile or a
little more of Engleman's Mill.
  These rocks, in their disintegration, produce the best of
soils in the State, inferior to none, except that, in their conti-
gtuity to the cliffs and the steep dip to which they are sub-
jected, they have been left more broken than is usual, while
they form larger tracts in other counties.

               HUDSON RIVER EPOCH.
  The rocks formed during the Hudson River Epoch are, in
Kentucky, naturally separated into three divisions, and are
widely exposed to view. But in this county it is only the

 

GEOLOGY OF LINCOLN COUNTY.



upper beds which give noticeable surface features, the others
being hardly seen, unless by one who knew their relations to
other beds, and sought them out.

  Lower Beds.-The rocks and shales of this division
overlie the Trenton beds in a narrow strip, which is not over
one half mile in breadth. The dip which carried the others
down has become steeper, and the rocks, like the last, are
soon lost to view.
  The hills have the same contours which usually mark the
position of those beds in other localities. Their surfaces are
in part covered with the fragments of limestone, broken down
by the disintegration and removal of the shales beneath.
The soils are usually stiff clays, and have a disposition to
cut into deep gullies. They have to be cultivated with some
care to prevent injury from this cause. They are best seen
in the county near and just south of the residence of Mr.
R. L. White, near Hanging Fork. (See map.)

  Middle Beds.-The Middle beds of the Hudson River
group have, like the last, large exposures in the State, and
even make up a large portion of the soils in Garrard county
-those on Sugar and Back creeks. In Lincoln county their
exposures are quite narrow, for the same reason which limits
the groups heretofore mentioned.
  East of the Danville and Stanford pikes they are better
exhibited on the farms of T. Alexander and J. T. Hackley.
but are seen in a narrow strip to where they cross Dix river.
The sandstones and sandy shales which compose them are to
be seen sometimes on the surface and again in a slight bluff
on the Hanging Fork. The peculiar mulatto-colored soil, and
the typical slopes to hills, are characteristic of the series in
other counties.  The concretionary member and the impure
limestones, with their wealth of shells and corals, are present.
  West of the pike mentioned above, these beds are seen
from the crossing of the Knoxville Branch Railroad up the
Hanging Fork for a number of miles. They only rise from



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GEOLOGY OF LINCOLN COUNTY



ten to fifty feet above that stream, and consequently give no
characteristic soils to the county.  Often large blocks are
torn up in the bottom of the stream, which would make
fine, smooth flag-stones. South of Hustonville, one of the
branches which enters Carpenter's creek has cut -down and
exposed those beds for a short distance.
  It will be understood that the series of rocks so far men-
tioned as occurring in Lincoln county are very limited in their
distribution, being covered outside of narrow lines by over-
lapping of higher groups. In the Reports on the Counties
of Madison, Garrard, Washington, Mercer, and Boyle, those
series will be more fully described, and their relations clis -
cussed. The reader who is interested in them is referred to
those reports for further information.

  Upper Beds.-The upper beds of the Hudson River
group are the superior rocks over a large part of Lincoln
county, and mark, by their outcrops, all that portion termed
the Blue Limestone Region, except the narrow exposures
referred to in the previously described divisions.  These
beds are not uniform in their composition and characters;
on the other hand, they are much varied.
  The lower portion of these beds is mainly thin limestones,
with a small proportion of clay shales between them. A few
six to eight () inch layers are included in them. The latter
are good solid stones, but the rest are disposed to be shelly,
and decompose comparatively fast.  These beds are seen
more particularly on and near Hawkins branch, and on each
side of the Hanging Fork, from Dawson's Mill to near Hus-
tonville. (See map.)
  Perhaps the soils derived from these layers are equal to
any in the State when they are at their best, and are at any
rate only excelled by those. derived from the best portion of
the Blue Grass beds. Blue-grass equal to any in the State
is grown on them, and there are farmers who claim it con-
tains more nutriment than the grass grown in better reputed
localities.



 11

 

GEOLOGY OF LINCOLN COUNTY.



   The rocks are literally filled with shells and corals, which
 so greatly distinguish this horizon in other counties; and it is
 to their chemical character that the fertility of these soils is
 due. Among the fossils seen here may be mentioned Plilodic-
 tya hi//i, Retepora angiea/a, Conchicoli/es corrugatus, Or/his
 /inneyi, Strep/orhyncus sinuatum, etc.
   The soils over these layers, even where they have been
very badly worn and exhausted, are restored in a short time
without other fertilizing agencies than being kept in grasses,
which help to decompose the rocks, and thus furnish the nec-
essary elements needed in good soils.
   Above these layers are some limestones which have rather
sandy shales included in them. They furnish good soils, and
are mellow, but more liable to wash than the preceding, espe-
cially on lands where the surface is rolling. These layers are
quite limited in extent.
  Overlying the above are some limestones which have a
greater proportion of earthy matters in them. The degrada-
tion of those give more clayey lands. There is some siliciouis
matter in them; and where this is the case, they are more
liable to be eroded by heavy rains. They are fertile, and,
where kindly used, are much valued by their owners.
  A succession of limestones, shales, and impure sandstones
constitute the rest of this division. These give the usual
varieties of soils seen in many other counties, as well as ill
Lincoln.
  Some of the limestones are quite pure and evenly bedded,
and are of great convenience to the people, being used for
fences and conmhmon building purposes, as well as for lime-
makinog. Some of the other beds are often quarried for those
purposes, and the inferior ones soon prove their worthless
character by crumbling to pieces. The beds, which contain
great numbers of Or/his lynx, associated with many other
fossil forms, outcrop in a great number of places; but they
are never fit for building purposes-they fall to pieces too
readily.



1 2

 


GEOLOGY OF LINCOLN COUNTY.



  The beds holding the great fossil corals, usually at the top
of the Hudson River group, are exposed at a number of
places in the county, and I have measured specimens of Col-
uninaria alveolata three feet in diameter. This coral bed is
not so largely developed in Lincoln as in Marion and Wash-
inigton counties; but some of the exposures are typical of its
character there, and contain the same association of fossils.
Hustonville and Stanford are both situated on the upper beds,
and are surrounded by fine bodies of agricultural land.
  During the whole period of time included in the Hudson
River Epoch, there were many and marked changes which
took place in the conditions existing on the floor of the old
ocean where those rocks were deposited. The change from
shale to limestone, from limestone to sandstone, must each
have been made by some disturbance here or at some other
point.
  The amount of silica contained in the whole group is con-
siderable, and much, if not all, of it must have been trans-
ported from some point where sandstones or other silicious
accumulations could have furnished the supply. Time after
time during this epoch was the floor of the sea raised so high
that the waves wlich passed over it left their marks ill the
shifting sands and mud at the bottom. These impressions
are seen at many points to-day; the ridges and furrows are
as plainly marked as if made to-day on a sandy beach.
  Time after time did the lime-secreting polyps rear their
coral reefs in the clear shallow waters, and by some change
those were broken down, and their structures buried by the
mud swept over them by waves or currents. At the close of
the Hudson River Period a great reef must have been here
for a long time, for through county after county can be seen
great accumulation of corals, many of which will weigh hun-
dreds of pounds each; and a great time was required for so
much lime to be secreted. This period closed here with an
influx of sand and mud, which destroyed the existing life, and
gave us a new period in geological time.



13

 


GEOLOGY OF LINCOLN COUNTY.



                   UPPER SILURIAN.
  When we come to examine the rocks in the west which
were deposited during the Upper Silurian age, it is found that
they do not have the great thickness nor the regularity of
distribution as are exhibited in the east. In many parts of
Missouri they are entirely absent. In Ohio, Indiana, and
Tennessee they are distributed in patch-like areas, and in
Kentucky, also, their placement is very irregular.
  In Central Kentucky, in those counties where they have
been studied to some extent, they show some curious phases
-sometimes they are one hundred or more feet thick; at
other points they have thinned down to almost nothing, or
are apparently absent.
  It has been thought by some geologists that the Blue Lime-
stone Region of Kentucky, Ohio, and Indiana, as well as the
Lower Silurian area of Middle Tennessee, was an island
during the Upper Silurian and part of the Devonian ages.
Some have gone so far as to teach that the exposed Lower
Silurian beds have never since that period been covered with
any higher rocks.  For Central Kentucky, the observations
made would leave these theories unsupported by facts.
  There are no evidences to show that there was any erosion
of the rocks at the top of the Hudson River group. On the
other hand, we have it demonstrated the great reef of corals
was overlaid at different points with rocks of very distinct
characters, and these within very narrow limits. These beds
are more or less of a local character, and if not deposited at
the same time, they were made under very dissimilar condi-
tions.

                  NIAGARA PERIOD.
  Medina Sandstone.-In the northeastern portion of
Lincoln county there is to be seen, in a niumber of places,
a series of buff sandstones, which sometimes show as hard
concretionary shales, which are disposed to break into squares
hardly more than an inch in diameter.



14

 


GEOLOGY OF LINCOLN COUNTY.5



  These beds at their thickest points are about thirty-five
feet in thickness; and erosion over them is comparatively
rapid, and they leave a soil which is sandy and easy to wash.
These tracts have a local name of " Bald Hill Soils," from a
locality in Garrard county where the rocks are exposed, and
so called because they have become, in places, sterile .from
the amount of sand which covers them.
  Internally they show yellow and green spots. Some of the
layers have a small portion of lime in them. This series is
well exposed on a road leading from Richmond Junction to
Dudderar's Mill, on Dix river. Here, at many places in the
hill-sides, can the Columniaria bed be seen covered tip in the
sand which was brought by the currents and swept over themn.
  A little north and east of Hall's Gap Station, and on thee
road thence toward Crab Orchard, they may be seen as they
are presented in Garrard and Madison counties.  While at
nearly every point exposed the layers seem worthless for
building purposes, yet locally there are some fine, durable
stones among them. At Mr. J. T. Lynn's, about a mile from
Hall's Gap Station, stones were quarried for foundations, steps,
etc.; a very desirable stone was obtained, which has every
appearance of being very durable.  They are easily taken
from the quarry, come out in good shape, and can be dressed
with an axe, so soft is their character. They harden on ex-
posure, and become of a deep buff color. At James' Mill,
on Dix river, the stack was made of stones taken from these
beds, and nothing could have suited the purpose better.
  In every direction from Crab Orchard these rocks may be
seen when looked for, presenting often small sterile spots;
in some cases they have been built into stone fences. Some
of the soils over these beds are fairly good where they have
been taken care of; but too often they present the features
which are mentioned in the REPORT ON WASHINGTON COUNTY.
  In some of the heavier layers, at particular points, are
included a few geodes filled with calcite crystals of a pinkish
color. In some instances I found small masses of celestite



1 5

 

GEOLOGY OF LINCOLN COUNTY.



or strontium sulpha/e in a heavy hard layer near the top, and
occasionally small nodules of zinc blende were seen.
   Many of the layers are remarkably full of sea-weeds; their
branching and matted stems covering layers everywhere as
far as they can be traced. One bed, a few inches thick,
seems to have held branching forms of C/haete/es corals; the
cavities filled with petroleum. Fossils are very few, and exist
only as very poor sandy casts. They probably include small
forms of Airypa r-elicu/a;'is and ZaSp/hentis bilateralis; but
such was their condition that they could not be determined
satisfactorily.
   In the western portion of the county those rocks are seen
between Moreland and Carpenter's Station; but here they
are thinner than in the eastern part, and present no new
phases. The whole series has the appearance of being a
reef-like accumulation, deposited largely or entirely by cur-
rents, and sometimes probably in the face of waves, as at
several points one or two layers have a wave-like structure.
The life which existed in the waters before seem to have all
been destroyed here at this time, and during the invasions
of the Medina sand seem not to have been fitted for any-
thing but plant-life, except in rare instances, and for a short
duration.

  Crab Orchard Shale.-Overlying the Medina sand-
stone in the eastern part of the county is a group of clay
shales, which reach in several instances a thickness of forty
feet, but thin down in others to a mere trace. These shales,
as seen in exposed places, are gray or white, sometimes
green; but when freshly excavated are black, green, olive,
blue, and red. They are soft and crumbling, and are soon
reduced to clay, and when tramped in wet roads become stiff
and tenacious.
  Within this deposit are a few hard. smooth plates of thin
limestones, with sometimes obscure markings of plants; these
plates are hard, and are often seen where all the shales haze
decomposed. These plates, and sometimes the shales, have



. i6

 


GEOLOGY OF LINCOILN COUNTY



I 7



a curved structure, and at times some of the laminx overlap
the thinned-out edges of others.
  Included in this bed are crystals of selenite (gypsum), and
crystals and nodules of iron pyrites; sometimes a plate of
iron shale is also seen. The whole bed seems to be impreg-
nated with carbonate of magnesia. To the presence of those
three minerals, in the form they assume, is due the peculiar
character of the magnesian compound, which, uilnder the flame
of Crab Orchard salts, is manufactured fromt these shales.
These shales are placed provisionally in the Clinton until
more is learned in regard to their relation.  As these shales
contain gypsum, soda, and potash. it would be advisable for
farners and others to make some experimental tests with
them as fertilizers.

  Other Beds.-Above the mouth of Flax creek, and near
Dix river, the following section is presented:
Ifeavv corniferous limestone layer ............... ... .   . 33 inches.
Covered space... .. .. .. . .. .. .. . .. .. .. . .. .. .  12 inches.
IDrab sandstone.... .. . .. .. . .. .. .. . .. .. .. . . 12 inches-
1',o(ck weathering to olive shale . ................. .  16 inches.
Sindstone with cauda-galli fucoids..... .. .. . .. .. . .. .. . 3 inches.
Sandstone with cutla-galli fucoids ............... ... .   . 20 inches.
Magnesian limestone ......................    . . . . . 2 inches.
.Magnesian limestone..... . .. .. . .. .. . .. .. .. . .. . 27 inches.
Crab Orchardshale..... .. .. .. . .. .. . .. .. .  .
  The magnesian limestone is probably Niagara, as in it
I found a species of Ialysites, Airita re/icaris, Stria/apora
cavernosa, a spirifer two and a half inches in length, and a
fivosife coral.  A heavy layer of limestone sometimes occu-
pies this position at other places, but I have not been enabled
to find any fossils in it.
  The sandstones above are well marked with specimens of
tie cock-tail sea-weed, and are seen sometimes resting oln
the Crab Orchard shale, and sometimes oil the Medina sand-
stone. They are very tough, rather more gray than drab in
color, and at points in Boyle and Marion counties have
included in them spines, teeth, and plates of large fishes.
    GEOL(G. SUB.-2

 


GEOLOGY OF LINCOLN COUNTY.



The plates are tuberculated externally. These remains be-
long to the genera Dinich/hys and Mfacrope/a/ic/hthys species
of which have been described from the rocks of Ohio by Dr.
J. S. Newberry. It would seem that those layers might rep-
resent both the Oriskany sandstone and the Cauda-galli grit.

                       DEVONIAN.
  Corniferous limestone.-The rocks which here have
been referred to the Corniferous are not in great force, but
present several distinct phases. In Lincoln, and to some
extent in Boyle county, there is to be seen a very peculiar
rock, which has been referred to this group, and may be a
part of it, though there are no fossils by which it may be
determined.
  It is to be seen in a single layer, varying from two inches
to twelve feet in thickness, and sometimes occupies nearly
all the space between the Hudson River Group and the Black
Slate. I have not seen it where either the Medina sandstone
or the Crab Orchard shales are present.
  At times it has very much the appearance of a breccia,
having a massive gray base with fragments of brown distrib-
uted irregularly through it. At other places, while it has the
same distribution of colors, it does not seem to have resulted
from brecciation, but from alteration of fossils, or such like
cause.
  I forwarded a fragment of this rock to Dr. Robert Peter,
Chemist to the Survey, as -brecciated limestone, which lies
in our undetermined series between the Hudson River Group
and the Black Slate." I quote his analysis and accompanying
notes:
  "A dark gray, fine-grained rock, mottled with whitish and
light yellowish gray spots of various sizes and shapes; con-
taining small cavities, some lined with small quartz crystals,
some filled with calc. spar, and containing imbedded semi-
opal, &c. It contains bituminous matter, the irregular infil-
tration of which has caused some of the mottling."



I 8

 


GEOLOGY OF LINCOLN COUNTY.



'9



            COMPOSITION- DRIED AT 2120 FAHRENHEIT.
talcium carbonate ....... .   ......... ............ 48.580
Magnesiun carbonate . ................. . . .......27-838
Alumina and iron and manganese oxides .......... . . . . . . . . 8.750
Soluble silica. ............................. .      .180
Insoluble silica and silicates ....................... . 8.480
organic matter and loss ......................... . 6.142

                                                         100. X)
  I doubt that any part of this rock is brecciated. It resem-
bles very MUch. the description of the Water Lime as given
in the Reports of the Ohio Geological Survey. I do not
kilow that this stone has been used for any purpose in the
county, except, when taken from railroad cuts, it has some-
timnes been broken and spread for ballast. This layer is well
displayed in the railroad ctt near McKinney's Station, and
in the cut near Junction City, in the edge of Boyle county.
Both of those points are on the Cincinnati, New Orleans and
Texas Pacific Railway.
  The cause which distributed this rock so singularly in the
county is obscure; but the other beds of Corniferous, unlike
theses were spread alike all over the county, and in a very
even manner.
  ]The Corniferous proper can be seen in its place, wherever
its horizon is exposed; while the remnants of it can be seen
over all the lower rocks within the limits of the county. It
is usually comprised in three or four layers of heavy-bedded
magnesian limestones, light buff in -the interior, but on the
exterior dark buff or brown.
  At places it is largely filled with masses of hornstone
(flint), and this gives to it a very rugged appearance. Be-
sides the hornstone in this condition, it is locally'filled with
silicified specimens of horn and honey-comb shaped corals.
These all seem to assist in its decomposition, and it is not
unusual to see spots where all the lime has disappeared, and
the ground covered with these silicious masses. Sometimes
the soft rocks beneath this series have been removed by nat-
ural clauses, and the massive layers of the Corniferous have
fallen in great blocks. Where there is but a small propor-

 

GEOLOGY OF LINCOLN COUNTY.



tion of silica contained in the beds, some of the layers would
make good stones for massive structures. They have, how-
ever, been seldom used for any purpose.
  Besides the hornstone and fossils contained in these beds,
there are often druses lined with quartz crystals, while crys-
tals of calcite and dog-tooth spar are not infrequent. Dolo-
mite crystals are sometimes seen in them, and occasionally
the cavities in corals, &c., are filled with petroleum. At sev-
eral places, a small bed of iron ore is intercalated with the
layers. Within the Corniferous are sometimes small caves,
and in Lincoln county many of the finest springs issue fromn
them. The, soil derived from these beds is a red clay, ConI-
tailing a fair proportion of lime and magnesia, and a large
percentage of silica. It is the finest wheat soil in the State,
in several p