Common wealth of Kentucky
Departm ent of Highways
KENTUC KY SOILS: THEIR ORIGIN, DISTRIB UTION
AND ENGINEE RING PROPER TIES
by
R. C. Deen
Research Engineer
A Report Presente d at the Kentucky Highway Conferen ce,
Universi ty of Kentucky , Lexingto n, March 29, 1956.
Highway Material s Research Laborato ry
Lexingto n, Kentucky
March, 1956
KENTUCKY SOILS: THEIR ORIGIN, DISTRIBUTION
AND ENGINEERING PROPER TIES
Soil Derivation
Soil is the product of the action of climate and living organisms
upon parent materials, as conditioned by local relief.
The length of
time over which these forces are operative is of great importance in
determining the properties of the final soil product.
are five principal factors in soil formation:
C\Ctivity,
5.)
3.)
l.)
nature of the parent material,
Altogether, there
climate, 2.) biological
4.) topography,
and
time.
The major differences in the soils of Kentucky result chiefly from
diff<;orences in
rived and
I.) the rocks from which the parent materials were de-
2.) the topographic position of the materials.
Topography controls, to a great extent, the depth as well as the
nature of the soil.
Erosion is greatly influenced by the slope of the
ground surface, and this also affects the proportion of rain water that
will seep into and through the soil to that which will run off on the surface.
The percolation of water through soil removes soluble matter and
fine particles from the surface layer, the "A" horizon.
The upper por-
tion of this horizon is also the zone of accumulation of organic matter.
The soluble matter and fine particles are carried to and deposited at a
lower depth, the subsoil layer or "B" horizon.
The underlying undi£-
ferentiated parent material is designated the "C" horizon.
A vertical
section through the different horizons - considered together as integral
parts of a natural unit - is called the soil profile (see Fig. I).
- 2 Soil differences depend not only upon the nature of the rock from
which the parent materials were weathered, but also upon whether these
materials have remained in their original positions or have been moved
and redeposited, and if the latter, by what agency.
When the parent rna-
terial has not been moved, the soils are known as residual.
These soils
consist primarily of the insoluble residue of rock material after the
soluble material has been removed by leaching and erosion.
Residual
soils are widely distributed throughout Kentucky, and were derived from
sandstone, shale, and limestone rocks, either singly or in various combinations.
Where the parent material has been moved and deposited by
water, the soils are known as alluvial; where the moving and deposition
is by wind, as aeolian; and by moving ice sheets, as glacial.
Most of the upland soils of Kentucky have been formed from re sidual materials.
Bottomland soils, which are extensive in many parts of
the state, were derived from alluvial materials.
A fine wind-blown rna-
terial known as loess covers a considerable portion of the Jackson
Purchase area; and a small area along the Ohio River from Oldham County
to Bracken County has been affected by glaciation.
Central Kentucky Physiography
The physiography of central Kentucky (see Fig. 2), which is a reflection of geologic features of the area, is largely controlled by the
Cincinnati Anticline, a broad arch that stretches north and south through
the centralportion of the state, reaching a peak in Jessamine County.
To the west the strata dip into the broad syncline of the Western Coalfield.
Fig. 1.
The Soil Prof ile. (Fro m Purd ue Univ ersit y
Expe rime nt Stati on Bulle tin No. 87)
PHYSIOGRAPHIC DIAGRAM
of
KEN TUC KY
By A.K. Lobeck
Fig. 2.
Phys iogra phic Diag ram of Kent ucky .
- 3 qui te
ks of the Cin cin nat i Arc h are
The dip s of the stra ta on the flan
eve r, has
by the eye . Thi s arc hin g, how
gen tle and can not be det ect ed
sur fac e of
n to be act ive , exp osin g on the
bee n suf fici ent to allo w ero sio
war d fro m
s in the sta te. Pro cee din g out
the dom e the old est for ma tion
a con cen tric
nge r for ma tion s are exp ose d in
the Jes sam ine Dom e, the you
arr ang em ent .
rai sed
Riv er lies an are a tha t was not
To the wes t of the Ten nes see
n Pur cha se,
ic tim e. Thi s are a, the Jac kso
abo ve sea lev el unt il late geo log
xic o, and
an em bay me nt of the Gul f of Me
was at one tim e at the hea d of
vel and cla y.
rec eiv ed dep osi ts of san d, gra
st
or Lex ing ton Pla in, inc lud es mo
The Inn er Blu e Gra ss reg ion ,
s. Thi s
Jes sam ine , and Me rce r Cou ntie
of Fay ette , Sco tt, Wo odf ord ,
the are a hav e
ing upl and ter rai n. Riv ers in
is a low lan d wit h a gen tly roll
ma jor
of 400 to 500 fee t. Exc ept for
ent ren che d the ms elv es to dep ths
cha nne ls,
is thro ugh sub terr ane an solu tion
stre am s, mu ch of the dra ina ge
, sol utio n
uen ts of lim esto nes are solu ble
And , sin ce ma ny of the con stit
sin kho les, are not unc om mo n.
cha nne ls, as wel l as cav es and
d fro m
ped dee p res idu al soi ls der ive
The lev el upl and s hav e dev elo
pla stic ,
w tha t suc h soi ls are rela tive ly
lim est one . Phy sic al tes ts sho
the wa ter
d bec aus e the bed roc k allo ws
yet the se are ver y wel l dra ine
aus e the
ts, and solu tion cha nne ls and bec
to esc ape thro ugh cra cks , join
ura l
ctu re. Ho wev er, whe n this nat
soi ls dev elo p a fra gm ent ary stru
rati ons for eng ine erin g pur ear thw ork ope
.
soi l stru ctu re is des tro yed in
as
and rea ct in mu ch the sam e way
pos es, the soi ls bec om e pla stic
.
oth er cla y-li ke ma teri als .
- 4 n as the Ou ter
Le xin gto n Pla in is kn ow
Th e are a en cir cli ng the
mp ara tiv ely im en Hi ll Co un try . Th e co
Ed
the
ing
lud
inc
s,
as
Blu e Gr
, hil ly co un try
le ha s pro du ced a rou gh
sha
d
de
ero
y
sil
ea
d
an
pe rvi ou s
d by the de co men Hi lls ha ve be en for me
Ed
the
of
ls
soi
e
Th
3}.
{se e Fig .
w and wi nd ing ,
s. Th e va lle ys are na rro
ale
sh
and
s
ne
sto
e
lim
po sit ion of
and bri dg es.
ich req uir e ma ny cu lve rts
wh
ms
ea
str
s
rou
me
nu
en ter ed by
po rt at no rm al
vid es po or pav em ent sup
pro
and
c
sti
pla
hly
hig
Th e soi l is
lan dsl ide s and are
slo pe s fre qu en tly pro du ce
t
cu
ile
wh
,
nts
nte
co
mo ist ure
ble m.
a ma jor en gin eer ing pro
soi ls of the
the Jes sam ine Do me , the
m
fro
ard
tw
ou
g
din
ee
Pr oc
Blu e Gr ass .
ila r to tho se of the Inn er
sim
re
mo
me
co
be
ass
Gr
Ou ter Blu e
tha n the Ed en
ted as sub gra de ma ter ial
sui
re
mo
are
s
on
riz
ho
Th e up pe r
t of the Ed en .
ial is ve ry sim ila r to tha
ter
ma
t
ren
pa
the
h
ug
ho
Sh ale s, alt
n {se e Fig . 4}
lin g na tur e of the ter rai
rol
tly
gen
the
t
tha
ate
It is for tun
cla y fin d·s its wa y
litt le of the un de sir ab le
t
tha
so
ts,
cu
r
hte
lig
req uir es
int o the sub gra de .
kn ow n as the
is a na rro w be lt of lan d
ass
Gr
e
Blu
the
g
din
un
Su rro
4) tha t are
co nic al kn ob s {Se e Fig .
the
by
ed
riz
cte
ara
ch
Kn ob s are a,
we st. Th is
r up lan ds to the sou th and
me
for
of
nts
na
rem
l
na
the ero sio
the Blu e Gr ass ,
the lim est on e co un try of
ng
cli
cir
en
a
are
le
sha
is a na rro w
the Cu mb erits we st and sou th, and
to
us
tea
Pla
ian
pp
ssi
wi th the Mi ssi
a reg ion of
n are a to the ea st. It is
tai
un
Mo
rn
ste
Ea
the
of
lan d Pla tea u
fla t and wi de.
th the ma jor str ea m. be ds
rou gh top og rap hy bu t wi
the we st and
us for m a bro ad be lt to
Th e Mi ssi ssi pp ian Pla tea
Th is be lt
the W est ern Co al Fie ld.
ng
cli
cir
en
,
ass
Gr
ue
sou th of the Bl
al rel ief
lim est on e, wi th sm all loc
m
fro
d
me
for
in
pla
d
is a rol lin g up lan
Fig. 3.
Fig. 4.
Top ogra phy of the Ede n Hill Cou ntry .
Blue Gra ss is
The gent ly rolli ng terr ain of the Out er
grou nd are the
show n in the fore grou nd. In the back
ss Reg ion.
coni cal knob s that enci rcle the Blue Gra
- 5 nd.
, the dra ina ge is und erg rou
Ex cep t for the lar ge r riv ers
ge fav or the
y and lac k of sur fac e dra ina
The gen tly rol lin g top ogr aph
Blu e Gr ass
ls, sim ila r to tho se of the
soi
al
idu
res
ck,
thi
of
ent
dev elo pm
uct ion . In dee p
all y goo d in Hig hw ay con str
are a. Th ese soi ls are usu
is fre que ntl y enl of pla sti c, uns tab le cla y
cut s, how eve r, a gre at dea
(se e Fig . 5).
cou nte red ,
al Fie ld,
dis onv ille is the We ste rn Co
Ma
und
aro
ed
ter
cen
ion
The reg
ntr y is a dis sec ted
str uct ura l bas in. Th e cou
a top ogr aph ic as we ll as a
An out sta ndi ng
mo der ate ly wid e val ley s.
pla tea u wit h rol lin g hil ls and
, is the bro ad
ll as of the Jac kso n Fu rch ase
fea tur e of thi s reg ion , as we
are a, for me d by
r riv ers . Th e soi ls of thi s
allu vi,a l bot tom s of the lar ge
to tho se of the
s and sha les , are sim ila r
the we ath eri ng of san dst one
Ea ste rn Co at Fie ld.
rou gh top oreg ion cha rac ter ize d by a
The Ea ste rn Co al Fie ld, a
inc lud es all of the
and dee p, nar row val ley s,
gra phy wit h nar row rid ges
at a mi nim um ;
Es car pm ent . Fla t lan ds are
sta tes eas t of the Po ttsv ille
lan ds hav e
le out cro p·, num ero us bot tom
but loc all y, in are as of sha
al upl and flo ats .
one s hav e giv en ris e to loc
dev elo ped . Ma ssi ve san dst
usu all y
se san dst one s and sha les are
The soi ls der ive d fro m the
ter rai n, the dee p
ial . Be cau se of the rug ged
qui te goo d sub gra de ma ter
sis t pre do mi in hig hw ay con str uct ion con
cut s and hig h fill s req uir ed
k in thi s are a
les (se e Fig . 6). Th e bed roc
nan tly of san dst one s and sha
eri ng sig nif ica nce .
thu s bec om es of gre at eng ine
the Gu lf
t pa rt of Ke ntu cky lyi ng in
Th e Jac kso n Pu rch ase is tha
pla in wit h ver y
reg ion . It is an und ula tin g
Em bay me nt, a c.o ast al pla in
soi ls are gre atl y
a has bee n cov ere d and the
litt le loc al rel ief . Th e are
Fig . 5.
Fig . 6.
roll ing ter rai n of the
In the for egr oun d is the gen tly
Pot tsv ille Esc arp me nt
Mi ssis sip pia n Pla tea us. The
Cum ber lan d Pla tea u of
rise s in the bac kgr oun d to the
Eas ter n Ken tuc ky.
tern Coa l Fie ld, sho win g
The rug ged ter rai n of the Eas
uir ed in hig hwa y con the dee p cut s and hig h fill s req
stru ctio n.
- 6 all old er ma ter ial s.
lo es s, wh ich ov erl ay s
n
ow
-bl
nd
wi
the
by
inf lue nc ed
iss iss ipp i, Oh io,
ve fo rm ed alo ng the M
ha
t
ten
ex
ge
lar
of
ns
Fl oo dp lai
an d Te nn es se e Ri ve rs.
of So ils
En gin ee rin g Pr ob lem s
ob lem s en co un ter ed
ea tly va rie d an d the pr
gr
e
ar
te
sta
the
in
So ils
so lut ion of a so il
us . Th e mo st log ica l
ro
me
nu
e
ar
m
the
of
in the us e
sit e. Un fo rtu ch oo se a mo re fav ora ble
to
or
d"
un
aro
o
"g
to
pr ob lem is
ntl y, the so il
no t fea sib le; co ns eq ue
ly
ral
ne
ge
is
ion
lut
so
na tel y, thi s
d co rre cti ve tre aton om ica l re me di es an
ec
t
es
gg
su
to
is
job
en gi ne er 's
.
the pr ob lem co nc ern ed
me nts fo r the so il an d
, pa rti cu lar ly in
rta nt so il co ns ide rat ion
po
im
st
mo
the
ly
ab
Pr ob
po we r. W he n
, is tha t of su pp ort ing
on
cti
tru
ns
co
nt
me
ve
ter ms of pa
lly ev er y en gin ee rin g
ts, ult im ate ly, vir tua
or
pp
su
il
so
t
tha
d
ze
it is re ali
t to the fro nt.
nc e is fo rci bly br ou gh
str uc tu re , its im po rta
sh ip be tw ee n
co nc ern ing the rel ati on
ise
ar
s
lem
ob
pr
us
ro
Nu me
he av e, fo r ex am ple ,
pe rfo rm an ce . Fr os t
nt
me
ve
pa
the
d
an
e
the su b gr ad
is no w kn ow n to va ry
n in re ce nt ye ar s, an d
tio
en
att
ial
ec
sp
ed
ha s rec eiv
cr ac ks in co nPu mp ing of joi nts an d
.
ed
ter
un
co
en
il
so
of
wi th the typ e
a so il is kn ow n
ted wi th so il typ e. If
cia
so
as
o
als
is
nts
cr ete pa ve me
as ur es sh ou ld be
mp ing , co rre cti ve me
pu
or
e
av
he
st
fro
to
to be su bje ct
oc cu rre nc e.
the pr ob ab ili ty of the ir
e
uc
red
to
on
cti
tru
ns
tak en du rin g co
of so ils , an d
ee rin g ch ar ac ter ist ics
gin
en
the
of
ge
led
ow
W ith a kn
ex ca va tio n
se so ils , es tim ate s of
the
of
n
tio
bu
tri
dis
d
an
the oc cu rre nc e
bil ity of
th ac cu rac y. Th e su ita
wi
de
ma
be
en
oft
n
ca
an d co nd iti on s
- 7 als o be det ering tho se at dam site s, can
fou nda tion ma ter ial s, inc lud
can be
ns of con stru ctio n ma ter ial s
min ed. The pos sib ile loc atio
tie s and
ilab le con cer nin g the pro per
sel ect ed if inf orm atio n is ava
are al dis trib uti on of soi ls.
roc k
are gen era lly lim ited to bed
Lan dsl ide s in hig hw ay wo rk
The mo st
sid e -hi ll fill s are req uir ed.
con diti ons wh ere dee p cut s and
out cro p in the
n fro m thi s sta ndp oin t is the
dan ger ous geo log ic for ma tio
es the cut
ntr al Ke ntu cky . In ma ny cas
Ede n Hil l Co unt ry of No rth Ce
bed roc k and
dw ay to be loc ate d ent ire ly on
is not dee p eno ugh for the roa
to cau se
e-h ill fill is oft en gre at eno ugh
the we igh t of the req uir ed sid
in a sid eter ial fro m the toe of a slo pe
slip pin g. The rem ova l of ma
the Hig hw ay
cau se slid es to dev elo p abo ve
hill cut is oft en suf fici ent to
(se e Fig . 7).
day
her fill s req uir ed in pre sen t
Wi th the dee per cut s and hig
fer ent
pro ble ms hav e inc rea sed . Dif
hig hw ay con stru ctio n ero sio n
uir e dif fer ent
cha rac ter isti cs and thu s req
soi ls hav e dif fer ent ero sio n
lec ts soi l
bot h int ern al and sur fac e, ref
tre atm ent s. Sin ce dra ina ge,
s to con tro l
l req uir e dif fer ent tre atm ent
pro per tie s, dif fer ent soi ls wil
wa ter con diti ons .
Soi ls
Ma ppi ng and Cla ssi fic atio n of
sig n,
n for use in the loc atio n, de
The nee d for soi ls inf orm atio
is gen era lly
ce of eng ine eri ng str uct ure s
con stru ctio n, and ma inte nan
h inf orm ay me tho ds use d to gat her suc
acc ept ed. Fie ld and lab ora tor
to use for
and ofte riti me s too exp ens ive
tion are ma ny and var ied -, a nee d for
sur vey s. Th ere is, the ref ore
ce
san
ais
onn
rec
ry
ina
lim
pre
rtc ut me tho ds.
the dev elo pm ent and use of sho
~;~:~~.
- 8 sif ic ave de ve lo pe d a cl as
ha
s
ist
nt
ie
sc
ils
so
l
Th e ag ric ul tu ra
er tie s
e to pr ed ic t so il pr op
us
n
ca
ey
th
at
th
m
ste
tio n an d ma pp in g sy
en ma pp ed
M an y ar ea s ha ve be
.
ity
tiv
uc
od
pr
l
ra
tu
ul
wh ich co nc er n ag ric
m ap s an d
in g ma pp ed . Th es e
be
e
ar
e
or
m
ny
ma
d
by su ch m eth od s, an
ef ul to
at wo uld be hi gh ly us
th
on
ati
rm
fo
in
of
h
alt
su rv ey s co nt ain a we
m ili ar
re po rte d in te rm s fa
r,
ve
we
ho
t,
no
e
ar
Th ey
the so il en gi ne er .
on re m ai ns
ab le so ils in fo rm ati
lu
va
in
of
ce
ur
so
is
, th
to hi m; co ns eq ue nt ly
gi ne er s.
la rg el y un us ed by en
lo gi st, ha s
ma pp ed by the pe do
d'
an
d
ie
sif
as
cl
as
Ea ch typ e of so il,
so il
sa me wh er ev er th at
the
ly
al
tic
ac
pr
be
ll
wi
ch ar ac te ris tic s th at
e fo r the
of sim ila rit y ho ld s tru
on
iti
nd
co
is
th
e
nc
Si
typ e is en co un ter ed .
ey s an d
ag ric ul tu ra l so il su rv
the
il,
so
a
of
s
tic
ris
en gi ne er in g ch ar ac te
in ve sti er in g re co nn aj. ss an ce
ne
gi
en
y
ar
in
im
el
pr
r
m ap s ca n be us ed fo
en gi ne er pr ac tic al ly id en tic al
ve
ha
to
d
un
fo
is
il
so
ga tio ns . If a gi ve n
, wh eth er
it ha s be en ma pp ed
er
ev
er
wh
B)
g.
Fi
ee
in g te st co ns tan ts {s
the in fo rev en in Te nn es se ej
or
ty,
un
Co
r
ce
er
M
in Fa ye tte Co un ty or
e am ou nt
, eli mi na tin g a la rg
ed
us
be
en
th
n
ca
rd
co
ma tio n al re ad y on re
ce ss ar y.
g no w co ns id er ed ne
of the ro ut in e tes tin
at er ia ls 'R es ea rc h
ss at the Hi gh wa y M
re
og
pr
in
w
no
is
e
Th er
te rm s
er in g sig ni fic an ce , in
ne
gi
en
e
giv
to
d
ne
t de sig
La bo ra to ry a pr oj ec
ho pe d
cl as sif ic at io ns . It is
l
ra
tu
ul
ric
ag
the
to
ne er ,
-fa m ili ar to the en gi
en te d by a sh ee t
ev en tu all y be re pr es
ll
wi
te
sta
the
in
il
th at ea ch so
Th e
ict io na ry of so ils ".
"d
of
nd
ki
a
in
8
g.
n in Fi
sim ila r to th at sh ow
ob se rv te ris tic s th at ca n be
ac
ar
ch
de
clu
in
uld
il wo
"d ef in iti on " of the so
as en gi ne er in g te st
an d co lo rs , as we ll
hs
pt
de
as
ch
su
,
ld
ed in the fie
co ns tan ts.
Hi ll Co un try .
A Sl id e in th e Ed en
Fi g. 7.
MAURY
SOI LS
Test Dol o
Horizon
Description
l
L.~37'Yo
P.L=B'Yo
A
Dark Brown Silt Loom
B
Brown Silty Cloy
GBR=B
ft
Max . Den. =105 lb./ cu.
LL. =4'2 %
P.l.= l7'r0
CBR •4
fl
Max Den.=IOO lb./ cu.
.
~
•
0
c
Cloy
Red dish -Bro wn Silty
0
L.L .=4 9 ?'0
P: 1.=19 "·
CBR .=4
ft
Max. Oen .•90 1b. /cu.
~
"0•
Bed rock
Fi g. 8.
otic Lim esto ne
High -Gra de Pho sp·h
ic tio na ry of So ils ".
A Pa ge Fr om a "D
- 9 Such an accumulation of soils data would permit the preliminary
soils work for an engineering project to be accomplished without the
engineer ever leaving the office.
Reasonably accurate estimates of
the engineering properties and problems associated with the soils can
be made before design or construction work is begun.
It was announced recently that the $7,000,000 topographic mapping
program of Kentucky had been completed.
Kentucky is now the first
state to be covered by a single-scale, topographic map.
On the other
hand, this state is greatly lacking in pedological maps and surveys.
Only 20 of Kentucky's 120 counties have been soil surveyed, and only
five of the soil maps are considered to be within modern standards.
Kentucky needs an effort, such as that used in the topographic mapping,
directed toward pedological soil surveys.
Since making the pedologi-
cal survey and map is a logical and economical point at which to start
the engineering soil surveys, the engineers of Kentucky will be at a
great disadvantage until much more soil mapping progresses to a much
greater degree of completion,