xt7mw6693m7p https://exploreuk.uky.edu/dips/xt7mw6693m7p/data/mets.xml Kentucky Geological Survey. 1884 books b97-20-37309380 English J.D. Woods, public printer and binder, : Frankfort, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Geology Kentucky. Birds Kentucky.Linney, W. M. (William M.) Beckham, Charles Wickliffe. Report on the geology of Spencer and Nelson counties / by W.M. Linney, including notes on the birds of Nelson County, by Chas. Wickliffe Beckham. text Report on the geology of Spencer and Nelson counties / by W.M. Linney, including notes on the birds of Nelson County, by Chas. Wickliffe Beckham. 1884 2002 true xt7mw6693m7p section xt7mw6693m7p

Maps and Charts for Kentucky Geological Survey
Publications, Series 2, Miscellaneous Reports, Volume 5

Map of Spencer and Nelson Counties is filmed after p. 59 of William
Linney's Report on the Geology of Spencer and Nelson Counties.

"Birds of Nelson County" is filmed after the Map of Spencer and Nelson
Counties following p.59 of William Linney's Report on the Geology of
Spencer and Nelson Counties.

Map of Montgomery and Clark Counties is filmed at the end of William
Linney's Report on the Geology of Clark and Montgomery Counties.

GEOLOGICAL SURVEY OF KENTUCKY.

JOHN R. PROCTER, DIRECTOR.

REPORT

ON TH E

GEOLOGY OF SPENCER COUNTY.

WITH MAP.

BY W. M. LINNEY.

STEREOTYPED FOR THE SURVRV

This page in the original text is blank.

INTRODUCTORY LETTER.

HON. JOHN R. PROCTMR,
Director of the Kentucky Geological Survey.
DEAR SIR: I herewith transmit to you my Reports on the
Geology of Spencer and Nelson Counties. I would suggest
that the two counties be exhibited on one map, and that the
two Reports be printed under one cover.
I have continued the divisions of the Hudson River Epoch
by colors on this map, and am happy to say that Mr. J. B.
Hoeing's careful and beautiful work has been very much
appreciated by all who have examined it.
I am, very truly, yours,
W. M. LINNEY.
FRANKFORT, Ky., January, I884.

This page in the original text is blank.

GEOLOGY OF SPENCER COUNTY.

Spencer county is situated in the north central portion of
Kentucky, and was formed in I824 from parts of Bullitt,
Shelby, and Nelson. Unlike the majority of counties ill the
State, its territory has remained unchanged since its first
formation. It has Jefferson and Shelby on the north, An-
derson on the east, Nelson on the south, and Bullitt on the
west. Its area is comprised in about one hundred and six-
teen thousand acres of surface, and in i88o its population
was 7,040. The county seat is Taylorsville, a neat little
town of about 5oo inhabitants. It is romantically situated
on Salt river, in an angle made by that stream and Brash-
ears creek. The various civil divisions have a small village
or post-office and store conveniently situated.
Salt river flows irregularly east and west through the
county, receiving Ash, Little Beech, Big Beech, Brashears,
Simpson, Elk, and Plum creeks as its larger affluentzs, while
into these and into the river innumerable rills carry the sur-
face water from the whole county. The Cumberland and
Ohio Railroad, operated by the Louisville and Nashville sys-
tem, passes through the county, giving needed facilities for
travel and shipping. Five turnpikes have been constructed,
but these are only a small portion of this class of roads which
the people should construct. Material for turnpikes is so con-
venient throughout the county that their cost of construction
should be at the minimum, and the whole county should have
a net-work of them, giving every citizen facilities of good,
substantial roads to every portion of the county.
Ta)ylorsxville has a high school of which her citizens are
proud, but the general schools of the county need better
houses and nmore money to make them as continuous and

REPORr ON THE

valuable as is required. the county has a fine moral, social,
end economic record, and with more good roads and better
schools, it would be amongst the most desirable counties in
the State for health, plenty, and happiness.
The general surface of the county is what is usually termed
hilly, but in fact there are no hills which rise above the gen-
eral level of the country. It is nearly a plane, through which
water has chiseled the many lines of drainage. Often these
reach a depth of two to nearly three hundred feet. From the
higher portions one may usually look over a large part of the
county, and even see the higher points in the counties lying
to the north, east, and south. Many of these views are beau-
tiful, and all of them are interesting, as from them one obtains
some idea of the vast erosion of material which has taken
place from over the present surface of this region.
\With the countless hollows which mark this county the
number of good springs is comparatively few, and the pota-
ble water of the county is largely drawn from wells, which
are comparatively easy of construction. Artificial ponds have
been largely made, the conformation of the surface and the
clay beds being very favorable for their construction.

GENERAL GEOLOGY.
Spencer county lies entirely within the so-called blue lime-
stone area of the State, and its bedded rocks are comprised
entirely within the limits of the Hudson River Group of the
Lower Silurian age, consequently the lower rocks, as seen in
the State, have not here been reached in the channels of the
streams; neither do the higher series now occupy their places
on the tops of the higher points. So in this county we may
not look for those massive building-stones which are exposed
to view where the Kentucky and her tributaries have cut
into them, nor to the higher series where the coals and iron
ores of the State are to be found. But here the elements
of wealth must be expected from the vegetable productions
by a wise system of farming, by cultivation and grazing, and
a particular care in the preservation of the soils.

GEOLOGY OF SPENCER COUNTY.

GENERAL SECTION OF THE ROCKS OF KEN-TUCKY.

Feet. Feet.

Quaternary 20) .. .. 0.. .. ....

Ca(rboirifi rouls -
Coal Measures (14b'.. . .
Conglomnerate (r MliHstone Grit x 14a

lSob-o lgri, eierots-il
tpper or Limestone (131,A........ . .. .. .. . .. .. 300 t 600
Lower or Silicious (13a)...... ... . .. .. .. . .. .. 300

DeItonl i -
Hamilton Period 10)..... .. . Black Slate.... 60 76
(',rniferous Period9e.. . . .. Corniferous...... .. 16 .

I oe r .S'', "itr8m -
Niagpra Period.56 . Niagara.)... . ... ... .
_-.a.. . . ... C(linton.... ... .. .. .. 100
l_-.)... . .. .. \I1 lina.... .. .. . . J

Lams i"- ,Chi ria a -
Trenton Periodl A46 andl 4r) Hs. . . o Hsn River .650)
-- (4aq.. '. Trenton t.. . . ]60 940
Birdse-,e .130)
Canadian Periodr... .......... . . .. .. . . . ....
('haz (3). . ...... .. .. ... . .. .. . .. .. ..50

The above table exhibits a sectional view of the relations
which the rocks of Kentucky bear to each other and the
position occupied by the Hudson River Group, upon which
is based the soils and other features of Spencer county.
The Hudson River Group in Kentucky occupies the larger
portion of the Blue Grass area of the State, and has been
divided for convenience of description into three almost natu-
ral parts: the Lower, the Middle, and the Upper beds. In
each of these divisions there is a general similarity in the
larger part of the rocks; in the soils as derived from them;
in the general aspect of the surface, as well as in the distribu-
tion of the trees which constitute the forest over them.
These divisions are of unequal thickness, as will be seen
from the following table, which gives their approximate thick-
nesses in this part of the State:

REPORT ON THE

HUDSON RIVER GROUP.
'Upper Hudson River beds ...... . . . . . . ........... 300 feet.
Middle Hudson River beds . . . . . . . ....... .... ..... . 150 feet.
Lower Hudson River beds . ............. . . . .. .. . .. 200 feet-
650 feet

LOWER HUDSON RIVER GROUP.
These, the lowest rocks exposed in Spencer county, are
seen along Salt river and the other streams in the eastern
part of the county, showing at their deepest cut points about
one hundred and sixty feet of their upper portion. They
do not, therefore, rise to the upper part of the county and
make any considerable area of soils. It is here and there
that portions, or sometimes the whole, of small fields are
based on this series. Here they are of the same character
as described in the reports of other counties which contain
them. Their general characteristics are to be seen in many
places-layers of compact, often half crystalized, limestones,
usually rough bedded, from an inch to a foot in thickness,
separated by beds of shale, often thin but sometimes several
feet in thickness. The limestones often contain nodules of
hardened clay, and sometimes iron pyrites. The shales are
often a blue clay with few marks of stratification, and in this
county remarkably destitute of organic remains. Some of
these layers make tolerably fair building-stones, and have
been used, to some extent, for that purpose. The layers of
great wave-marks have lost none of their characters through
a half dozen counties, but are seen wherever their horizons
are exposed.
In all the stream beds where this division is seen the broken
blocks of limestone are exposed in great quantities. The
shales are torn out and dissolved by water, and the ledges
of stone break off by their own weight, where not originally
fractured, and drop down. Roads along those branches are
therefore often almost impassable from their roughness. The
same cause has often produced the same effects on the hill-
sides where the loose blocks cover the ground; and where no
care has been taken to preserve them the fields, or part of

GEOLOGY OF SPENCER COUNTV 9

them, become barren, rocky places, from which all the soil
has been washed away. Those places have usually been
turned out as worthless, and are enlarging each year. With
the removal of those stones and a part of the ledges, those
places could readily be brought back to grass or timber lands,
while the stones could be built into fences, and thus preserve
in part the timber, which is becoming much scarcer than the
interest of these lands require.
The soils on this series of rocks were of good quality, and,
where taken good care of, are very lasting. the destruction of
the shales and limestones being a continual source of renewal.
White oak was the great prevailing timber which covered
these soils, and even to-day, when the forests have been so
largely destroyed, its well-known character is exhibited in the
remaining woodlands. Sugar maple, red oak, sassafras, black
hickory, perhaps, were the most prevailing trees which grew
with the white oak.
Over some of the exhausted soils, and in some of the
remaining woodlands, young trees are coming up rapidly,
and, with care, in time would be very valuable; but, with
the exception of the black walnut, none of them have re-
ceived any care or protection. Among the young timber
there are places where the white oak is in fair numbers, and
apparently of vigorous growth.
This series of rocks, by a dip to the north and west, are
carried beneath all the drainage lines, and are hid everywhere
over the general surface by the rocks which compose the next
member of the Hudson River Group. The fossil forms which
they contain are very numerous, and are those species which
mark the same series in all the counties to the south and east.
Trinuicleus concentricus, Calymene senarit, A sap/ihus gigas,
Conularia Irentonensis, Gr;ap/oli/es gracilis, BeIle;-ophIon bibo-
ba/ts, Lep/cena sericea, Or/Izzs nrul/isec/a, and other, forms pecu-
liar or general to this horizon, are often seen, but rarely in
good condition. The shales are barren, and the limestones are
so hard that they give few specimens worth collecting. Some
particles of sulphate of lime, and a little iron pyrites, are often

REPORT ON THE

included in the shales or rocks, and in one instance a weak
brine spring was known to exist in them. So alike are all
the features of the Lower Hudson in Spencer, as compared
with the same division in Madison and all the intervening
counties, that one almost feels sure, in many places, that he
has been at the same point in other counties. The layers
of rock, the character of shales, the peculiarities of soils,
the distribution of trees and other plants, the variety of
slopes, and the condition of the fossils, all are so analogous
that they seem like well remembered places.

MIDDLE HUDSON RIVER BEDS.
This division of the rocks makes the upper surface in the
eastern portion of the county, and, like the former beds, pass
beneath the country in going to the north and west. The
map which accompanies this report shows well the relation
existing between the three divisions included in Spencer.
The Middle beds, which were described in the old series of
the Kentucky Geological Reports, by Dr. David Dale Owen,
under the name of the Silicious Mudstone, have, through a
number of counties, a nearly uniform thickness of about one
hundred and fifty feet. Their general character is very much
alike through the belt of counties studied so far; but some
changes have been noticed in their northwest extension.
As has been stated in the reports on other counties, these
beds are made up of mud-like sandstones and shales, with a
number of limestone layers included in them. To the south-
east some of the sandy layers are quite heavy bedded, and
leave a concretionary character. I was not able to find either
of these layers in Spencer county, though, with one other
exception, there is a general resemblance in the more com-
mon features. Within the lower third of the series there is
a layer of limestone which is marked with the great wave-
like character so common to the lower beds, and from some
slight analogies it seems as if the origin of the two phases
were the same.

I O

GEOLOGY OF SPENCER COUNTY.

There are many places where partial sections of these rocks
can be seen and studied, and they show, that while the heavier
layers of sandstones have disappeared, the general mass of
shales retain their characters very well, but that there has
been introduced a larger proportion of limestone.
Generally the soils derived from these rocks are naturally
very good. Their decomposition is rapid, and they give con-
siderable depth to the soils. Their porosity allows the infil-
tration of water through them, and the sandy layers hold a
good deal of moisture. This is a very favorable condition, as
they are well drained, and soon dry out on the surface in wet
seasons, and in dry ones the amount of moisture stored be-
neath, by its evaporation, brings not only plant food from
below, but moisture to sustain the growving crops.
Over the larger part of the County covered by this series
the surface lies in narrow ridges, with steep slopes on each
side. These ridges and slopes are cultivated year after year
without much apparent injury; yet their destruction is rapid
from the continual washing away of the surface. The decom-
position is so deep that a continual renewal of the soil on the
surface is produced by the exposure of the shales from be-
neath. There are no other soils in the State which could
stand half the rough, careless treatment much of this land
has received without being permanently ruined. Year after
year of corn-growing on slopes of twenty to forty degrees is
usually very destructive to our lands; but in many cases these
do not seem to be much injured by such treatment.
There are some conditions where these soils, or a part of
them, have been badly worn. It is where some hard, sandy
shales come in; these break up into fragments, and produce,
from some cause, poor patches in the fields. In the cultiva-
tion of these lands it would be better to plant in each of the
hollows over a farm some shrubs or small trees, which would
hold back and preserve the material which is so rapidly
washed away, and then if bands of grass land were left half
way from the top to the bottom, extending around the slope,
a great saving of soil could thus be made.

REPORT ON THE

An analysis of eleven specimens of these soils, made by
Dr. Robert Peter, gives the following average composition:
AVERAGE OF ELEVEN' MIDDLE HUDSON SOILS.
organic and volatile matters...... .. .. .. .. .. .. . .. .. . 4.778
Alumina and iron and manganese oxides .................. 7.064
Lime carbonate.... .. .. . ... . .. .. .. .. .. .. . .. . .101
Magnesia.... .. . .. .. .. .. . .. .. .. .. .. .. . .. . .605
Phosphoric acid (P2 06)...... .. .. . .. .. .. .. .. . .. . .165
Potash extracted by acids ........................ .155
Sand and insoluble silicates.... .. .. .. .. .. .. . .. .. .. . 86.551
Water expelled at 2120F ....................... not estimated
Potash in the insoluble silicates ........... .. .. . . . not estimated
In his notes on these soils the Doctor says: "These soils
contain average organic matters, alumina and iron oxide
and phosphoric acid; more than average magnesia and sand
and insoluble silicates, and less than the average of carbon-
ate of lime."
As these soils give, on an average, a less quantity of lime
than is usual, it would be interesting, and perhaps very profit-
able, for the farmers residing on them to institute a series of
experiments lasting through several years, in which various
quantities of lime were added to these soils. This would be
a cheap experiment, as from nearly every drainage line cut
through these soils can be procured limestone in quantity
which will burn into a good quality of lime.
The original forests over this series in Spencer was, as usual
in many other counties, composed largely of beech, often form-
ing as much as seventy-five per cent. of the trees. In some
places sugar maple and white oak were common species, while
yellow poplar and walnuts of fine proportions were scattered
in some quantity. Various other trees were sometimes seen,
but always few in numbers. Over what is called Briar Ridge
about i830 a destructive tornado leveled all of the timber for
some distance, and the trees now standing have grown since
that time. They are largely white oak, red oak, poplar, wal-
nut, ash, and beech.
This is not a series where fossils are well preserved or easy
to collect. The casts of Calynene senaria, Strophomena al/er-
nala, &c., are not uncommon in the sandy layers, while in the

GEOLOGY OF SPENCER COUNTY.

lower part of the limestones some of the forms of the Lower
Hudson are seen. Towards the top Strepftorhyncus p/ano-
convexus is very common, and is usually associated with one
or more of the common forms of chatetes corals.
In the northern part of the county I found two specimens
of a brachiospongia, perhaps digi/ata. One of these was loose
on the surface, but the other was imbedded in a layer of the
mudstone. This is an interesting fact, for it is not positively
known from what horizon the specimens found in Franklin
county came, they having been found separated from any
matrix, usually in the beds of the creeks. The one found
in Mercer county came from the top of the Trenton. So
we at last have-two known horizons for this singular fossil.
The similarity of this series, as seen in Spencer and com-
pared with other counties, is no less striking than that ex-
hibited in the Lower Hudson beds. The deep-cut hollows,
the narrow divides, the plant distribution, and other natural
features are much alike. This division, like the former, dis-
appears under the surface' and the streams as we go north-
westerly through the county. The map and section exhibit
this in an interesting manner.

THE UPPER HUDSON RIVER BEDS.
This series make the last and upper division of the rocks
of the county, but are not so homogeneous in their charac-
ter as the other divisions. They differ much at different
elevations in soil, rocks, timbers, &c., yet it is not advisable
to subdivide them by further names; but some description of
the unlike characters is necessary.
The lower part of these beds is tolerably pure thin lime-
stone, containing quite a percentage of phosphate of lime.
These limestones are to be seen resting on the Middle beds
through the county. They are often irregularly laminated,
and were evidently largely deposited in circling currents,
which left their impress on them everywhere that they are
exhibited to view. The grinding of the currents has left
them nearly barren of fossils wlhose forms can be determined,

REPORT ON THE

but it is the horizon of Pt/iodicdya hili, Or/iks linneyi, Con-
chico/i/es corrugatus, Relepora angulata, Cyrtoceras va/adng-
hami, &c. These rocks are about seventy-five feet thick,
and give what are usually considered the finest lands in the
county. Blue-grass undoubtedly grows better over them than
on any other beds, and they lie usually in gentler slopes; but
in Spencer there is not a large extent where they are at the
surface. Their rich character is largely due to the amount
of phosphates which they contain; so in this case the appli-
cation of bone-dust and like fertilizers is of little benefit.
Farmers had, as a usual thing, better experiment on their
farms with a variety of fertilizers than to purchase at a large
outlay those which their lands do not require. Too much
time and means have been wasted from an ignorance of
these subjects.
The principal distribution of timbers over these soils was
like that in other counties, being largely made up of blue
ash, wild cherry, chinquapin oak, hackberry, white ash, sugar
maple, black walnut, and shell-bark hickory. One passing
through parts of these counties of the Blue Grass Region.
and seeing the dying remains of its woodlands, could hardly
believe that once this region was covered with a continuous
forest of splendid trees.
Overlying the last are some one hundred and thirty feet of
limestones that are thin and shelly; except in a few instances,
disposed to decompose readily when exposed. These layers
are very full of the remains of shells and corals, and, from the
vast numbers of one species, have been named the Lynx bed.
Through many of these layers there is quite a percentage of
clay, which assists very much in their decomposition. Phos-
phate of lime is present in some layers in considerable quan-
tities.
There are two or three layers of stone in this section which
are sometimes worked into very good foundation stones. The
same layers, however, when followed for some distance, be-
come unfit for use. All of this section melts down into very
fair soils, and where the proper care of them is taken, they are

GEOLOGY OF SPENCER COUNTY.

almost inexhaustible. Yet careless criminality or ignorance
has left some sad blots on them over the county in the shape
of bare places where the soils have been entirely washed
away. These places, by being covered with refuse, are soon
restored, and it is now common to see in this county fafms
which had been thought to be worn out restored to a high
degree of fertility. The increase in stock raising and in the
knowledge of the proper cultivation of lands and their care
have sensibly increased the character and worthi of many
tracts of land, and it is to be hoped that this will be further
extended.
A mixture of maples red oak, white oak, white chestnut
oak, walnut, hickory, black ash, mulberry, white elm, buck-
eye, water beech, and red bud were the principal timbers.
The forests have been largely destroyed, and there is urgent
aeed that farmers should take some care in propagating a
few acres of trees on each farm. In many places, on all the
various soils, there is sorme little pains taken to leave a few
black walnuts, but all the oth er species of valuable trees
should be cared for, as it is evident that mixed timbers
will grow better, give a better return, and be less liable to
death from insects, disease, or other causes than one spe-
cies. White oak, poplar, wild cherry, black walnut, ash,
black locust, mulberry, and catalpa should at least be found
in numbers on every farm, and these receive the same care
and solicitude as is given to a well-kept orchard.
In this section of the rocks fossils are wonderfully plenty
and well preserved. Orthis lynx, Orthis occidentalis, Or/his
den/a/a, S/ropihomena al/ernata, Ambonychia i-adia/a, with vari-
ous species of chaetetes, are especially abundant.
Two specimens of soils were collected from the farm of D.
B. Wigginton, some two miles north of Fairfield. The first
was taken from a field which had been cultivated for some
seventy-five years, and was eight inches of top soil, based
on the Lynx beds. The second was subsoil below the first,
ten inches in thickness. These samples were forwarded to
Dr. Peter, who has furnished me the following analyses:

I 5

REPORT ON THE

COMPOSITION OF SOIL AND SUBSOIL, DRIED AT 2170 F.

1 2

Organic and volatile matters.. .. .. . .. .. . .. .. . 3.550 3.205
Alumina and iron and manganese oxides ... ...... . . . 7.809 11.849
Lime carbmate.. .320 .295
Magnesia. . .. .. ... .. .. . .. .. .. . .250 .274
Phosphoric acid (P2). 05. ... . . . . . . .236 .221
Potash (extracted by acids).... . . .. ......... .228 .470
Soda (extracted by acids)........... ...... . .192 .117
Water, expelled at 3400 F.................... . .727 830
Sand and insoluble silicates.. 86.175 82 320
99.487 99.581

Hydroscopic moisture (per cent.)..... .. . .. .. . .. . 1.850 1.063
Potash in the insoluble silicates (per cent.). . . ... 1.063 1.206
Soda in the insoluble silicates.... .. .. . .. .. . .. . .473 .384

A portion. of the time this land has been over cultivated in
exhausting crops, but yet, as Dr. Peter says, " these still
remain better than average soils, the subsoil being especially
rich in potash; " and adds: " No doubt their fertility might be
improved by an addition to the organic matter-humus-by
stable manure, or the culture of clover or other green crops
to be ploughed under."
Above these is about one hundred feet of mixed layers of
limestones and shales. Near the bottom are several layers
of heavy-bedded limestones, with more or less clayey matter
in them, and mud shales between them. Those layers often
have strings of calcite in them, giving what is called a partial
Birdseye appearance. In places these layers are firm, solid,
good wearing stones, of which houses have sometimes been
erected, while at other places they are disposed to break and
split into fragments which crumble into soil. This is perhaps
largely due to the presence of iron pyrites, which, in oxidiz-
ing, rupture the layers, and assist in dissolving them. The
soils derived from these and other layers near this horizon
give heavy beds of clay, which make quite a good soil, and
are highly prized as wheat lands. They grow very fine
crops of clover, and are often sown in that plant to improve
the soil, and prepare it for grain growing. These soils are

GEOLOGY OF SPENCER COUNTY.

easy of improvement, seeming to possess in themselves all
the elements of richness, except vegetable matter, which is
given by the turning under ot green crops.
The timber here was largely white oak, and these clay
lands are usually here known by the name of white oak lands.
Sometimes, however, on the flatter ridges, beech made quite
a feature, and in this case the larger amount of moisture may
have had much to do with the change of timber, and also for
the preference of these lands for corn.
The fossils in these heavy layers are several forms of mur-
chisonias, lamellibranchs, and a leperditia; all of them are usu-
ally poorly preserved.
At the base of this section is everywhere seen fragments
of chert, which must have been at one time a continuous
bed in this horizon, but giving many curious concretion-like
forms. Throughout this chert, and associated with it, are
numerous forms of fossils-Orthis dentata, Chote/es fibrosa,
Heterosponoia subramosa, &c., silicified. In a number of places,
at the heads of drainage lines, where once were evidently
marshy places, beds of bog iron ore have been deposited,
the presence of the silicious chert aiding in its formation.
This ore is sometimes six or eight inches thick, but is quite
poor, and very limited in quantity.
Above the last the beds are quite variable. Sometimes
there is thirty feet of yellowish sandy layers or blueish sili-
cious shales, with limestones and clay shales. Again these
are largely magnesian, showing that the conditions which
afterward formed the heavy magnesian limestones of the
Upper Silurian had begun its work. Above these, and con-
stituting the highest layers seen in the county, and on its
western and northern boundary, is sometimes the great coral
bed so common in other counties at this horizon -Strepte-
lasma corniculum, Te/radium minus, Columnaria alveolata,
Columnaria s/ella/a, Bea/ricea nodulosa, and Bea/ricea undu-
la/a. Among these are often some of the brachiopod shells
and the smaller corals. These fossils are distributed in soft
GEOLOG. SUR.-2

I 7

REPORT ON THE

earthy limestones and shales, in which indurated clay balls
of many shapes are very common. These hardened clay
masses resist decomposition in a remarkable degree, seeming
at times to remain longer than the friable stones in which
they are included.
While this ends the existing rock series of the county, it
does not include what has undoubtedly been spread over its
whole surface in past ages. Within a few miles from the
line of the county the rocks of the Upper Silurian are seen
in place on three sides, and the time must have been recent,
in a geological sense, since this period had its place in the
rocks of the county. All the rocky series described in the
foregoing pages have, in time, stretched unbroken over the
county, and when we see the great number of valleys which
have been dug out of its floor by the action of the present
lines of drainlge, it is easy to comprehend what an im-
mense amount of material has been removed from over the
higher parts of the surface.
Occasionally in the soils are now found silicious remains of
rocks and fossils which belonged to series much higher than
any which now are seen. These extend up to and include
the conglomerate pebbles, which are now, wherever in place.
700 or 8oo feet higher than the rocks seen in this county.
The general erosion of the surface of the county is in a
northwest direction, and agrees with the position of the
KENTUCKY ANTICLINAL, an uplift which passes through the
State to the southeast of Spencer county. This erosion has
been modified most probably by an uplift in the region of
the northern lakes, made subsequent to the greater denuda-
tion of the surface.

BOTTOM LANDS.
Along Salt river and some of the larger creeks there are
bottom lands which are composed of mixed material brought
down and deposited by the action of the streams. As Salt
river has its source in Boyle county amongst the waste of
the conglomerate, and flows down over the lower subcarbon-

GEOLOGY OF SPENCER COUNTY.

iferous, cuts through all the Hudson River beds and into
the Trenton, it may be seen that those alluvial deposits are
the comminuted fragments from a great -variety of rocks
mixed with the vegetable remains from many soils. These
bottoms are, from narrow strips of sloping surfaces, where the
Lower Hudson cuts through, to wide level valleys as the
Upper Hudson is reached, toward the west of the county.
These bottoms have been highly prized in time as very
fertile lands, receiving, when overflowed, the deposits of fine
earth, leaves, and mold brought down by the river. The
country above has, however, been so devas